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2020 Volume 48 Issue 12
2020, 48(12): 1597-1606
doi: 10.19756/j.issn.0253-3820.201339
Abstract:
Ovarian cancer is a serious threat to women's health, and its mortality rate is the highest in gynecological cancer. At present, there is a lack of effective and convenient early diagnosis technology for ovarian cancer. Most of the patients with ovarian cancer are found in the middle and late stage and miss the best time for treatment. Therefore, the rapid, sensitive, economic, and accurate detection of early ovarian cancer is of great significance. In recent years, lysophosphatidic acid (LPA) has been found to increase in serum in the early stage of ovarian cancer, but less in other diseases. Therefore, LPA is a promising and highly specific marker of ovarian cancer. To detect LPA, many detection techniques and methods have been developed. In recent years, great progress has been made in this field. This paper summarizes the detection methods of LPA, and focuses on the important progress in this field in recent years. Finally, the challenges and prospects of LPA detection in real clinical application are also prospected.
Ovarian cancer is a serious threat to women's health, and its mortality rate is the highest in gynecological cancer. At present, there is a lack of effective and convenient early diagnosis technology for ovarian cancer. Most of the patients with ovarian cancer are found in the middle and late stage and miss the best time for treatment. Therefore, the rapid, sensitive, economic, and accurate detection of early ovarian cancer is of great significance. In recent years, lysophosphatidic acid (LPA) has been found to increase in serum in the early stage of ovarian cancer, but less in other diseases. Therefore, LPA is a promising and highly specific marker of ovarian cancer. To detect LPA, many detection techniques and methods have been developed. In recent years, great progress has been made in this field. This paper summarizes the detection methods of LPA, and focuses on the important progress in this field in recent years. Finally, the challenges and prospects of LPA detection in real clinical application are also prospected.
2020, 48(12): 1607-1615
doi: 10.19756/j.issn.0253-3820.201421
Abstract:
Metal organic frameworks (MOFs) are a new type of porous materials with some unique characteristics such as uniform pore size, adjustable pore structure, easy synthesis and structural diversity. Ionic liquids-modified MOFs (ILs/MOFs) composite materials not only retain the structural characteristics of MOFs, but also have advantages of adjustable physical chemical properties and high stability of ILs, showing great application potentials in separation and analysis fields. This article mainly summarizes different preparation methods of ILs/MOFs composite materials, and provides an overview of ILs/MOFs in separation and analysis, including adsorption/extraction, chromatographic separation, spectrum and electrochemical analysis, in the latest five years. The trends of future development are also discussed.
Metal organic frameworks (MOFs) are a new type of porous materials with some unique characteristics such as uniform pore size, adjustable pore structure, easy synthesis and structural diversity. Ionic liquids-modified MOFs (ILs/MOFs) composite materials not only retain the structural characteristics of MOFs, but also have advantages of adjustable physical chemical properties and high stability of ILs, showing great application potentials in separation and analysis fields. This article mainly summarizes different preparation methods of ILs/MOFs composite materials, and provides an overview of ILs/MOFs in separation and analysis, including adsorption/extraction, chromatographic separation, spectrum and electrochemical analysis, in the latest five years. The trends of future development are also discussed.
2020, 48(12): 1616-1624
doi: 10.19756/j.issn.0253-3820.201172
Abstract:
Food safety has always been one of the most important issues for human being. With the variety of food, it is required to develop rapid, low-cost and convenient detection techniques for food safety. As a representative, paper-based detection techniques have developed rapidly from simple test papers to various microfluidic paper-based devices. The paper-based analytical devices combining paper platform with a variety of advanced analysis methods have shown great application prospects for rapid food safety testing. In this review, the surface functionalization and modification of paper are introduced. Then, the construction and development of various detection techniques are discussed, including colorimetric analysis, fluorescent analysis, electrochemical analysis, surface enhanced Raman spectroscopic analysis, and multimethods on paper-based platforms for the application in rapid food safety detection. Finally, the prospects and future challenges of rapid detection techniques in food safety are also discussed.
Food safety has always been one of the most important issues for human being. With the variety of food, it is required to develop rapid, low-cost and convenient detection techniques for food safety. As a representative, paper-based detection techniques have developed rapidly from simple test papers to various microfluidic paper-based devices. The paper-based analytical devices combining paper platform with a variety of advanced analysis methods have shown great application prospects for rapid food safety testing. In this review, the surface functionalization and modification of paper are introduced. Then, the construction and development of various detection techniques are discussed, including colorimetric analysis, fluorescent analysis, electrochemical analysis, surface enhanced Raman spectroscopic analysis, and multimethods on paper-based platforms for the application in rapid food safety detection. Finally, the prospects and future challenges of rapid detection techniques in food safety are also discussed.
2020, 48(12): 1625-1632
doi: 10.19756/j.issn.0253-3820.201445
Abstract:
Food safety is closely related with human life and health, therefore, it is particularly necessary to establish a fast, sensitive, simple and convenient testing means for food contaminants. Surface-enhanced Raman spectroscopy (SERS) has the characteristics of quickness, convenience and high sensitivity for the field detection and analysis of food contaminants. In this work, the capillary effect of filter paper combined with the quick detection function of SERS technology was used to prepare SERS multi-functional base sensor cards. Firstly, a large area of dense nano membrane was prepared by using the self-assembly method of liquid-liquid interface with the synthesized gold nanotriangle, which was transferred to the surface of filter paper as SERS base membrane. Crystal violet (CV) was used as the Raman probe molecule to investigate SERS sensitivity and repeatability of the substrate membrane, and the plasticizer benzyl butyl phthalate (BBP) in liquor, thiabendazole (TBZ) on the peel surface and antibiotic malachite green (MG) on the fish surface were also detected. The results showed that the concentration of BBP, TBZ and MG could be detected at 1×10-8 mol/L. This kind of SERS substrate membrane showed a fast detection speed, high sensitivity, convenient operation, and a great potential for SERS analysis.
Food safety is closely related with human life and health, therefore, it is particularly necessary to establish a fast, sensitive, simple and convenient testing means for food contaminants. Surface-enhanced Raman spectroscopy (SERS) has the characteristics of quickness, convenience and high sensitivity for the field detection and analysis of food contaminants. In this work, the capillary effect of filter paper combined with the quick detection function of SERS technology was used to prepare SERS multi-functional base sensor cards. Firstly, a large area of dense nano membrane was prepared by using the self-assembly method of liquid-liquid interface with the synthesized gold nanotriangle, which was transferred to the surface of filter paper as SERS base membrane. Crystal violet (CV) was used as the Raman probe molecule to investigate SERS sensitivity and repeatability of the substrate membrane, and the plasticizer benzyl butyl phthalate (BBP) in liquor, thiabendazole (TBZ) on the peel surface and antibiotic malachite green (MG) on the fish surface were also detected. The results showed that the concentration of BBP, TBZ and MG could be detected at 1×10-8 mol/L. This kind of SERS substrate membrane showed a fast detection speed, high sensitivity, convenient operation, and a great potential for SERS analysis.
2020, 48(12): 1633-1641
doi: 10.19756/j.issn.0253-3820.201179
Abstract:
A molecularly imprinted sensor was fabricated, and a method based on enhancing electrochemiluminescence (ECL) signal of Ru(bpy)3Cl2 using resonance energy transfer (RET) was established for ultra-sensitive determination of gibberellin (GA3). Au-doped g-C3N4 (g-C3N4/Au) was prepared on the surface of glassy carbon electrode, and then o-phenylenediamine was electropolymerized to achieve a molecularly imprinted polymer (MIP) film. The film was then eluted by methanol-acetic acid to obtain molecularly imprinted cavities for specifically recognizing GA3. Ru(bpy)32+ was used as probe and g-C3N4/Au was used as energy donor. The RET between Ru(bpy)32+ and g-C3N4/Au was used to enhance ECL intensity of Ru(bpy)32+. In addition, ECL-RET was combined with molecular imprinting technology to improve selectivity of the sensor. With the increase of the concentration of GA3, the molecularly imprinted cavities recombined with GA3, which made the ECL intensity gradually decreased. Under the optimized conditions, there was a linear relationship between ECL intensities and GA3 concentrations in the range from 4.00×10-14 mol/L to 7.00×10-11 mol/L, and the detection limit was 1.64×10-14 mol/L (3S/K). The sensor was successfully applied to the detection of GA3 in beer, and the recoveries were 95.7%-103.7%.
A molecularly imprinted sensor was fabricated, and a method based on enhancing electrochemiluminescence (ECL) signal of Ru(bpy)3Cl2 using resonance energy transfer (RET) was established for ultra-sensitive determination of gibberellin (GA3). Au-doped g-C3N4 (g-C3N4/Au) was prepared on the surface of glassy carbon electrode, and then o-phenylenediamine was electropolymerized to achieve a molecularly imprinted polymer (MIP) film. The film was then eluted by methanol-acetic acid to obtain molecularly imprinted cavities for specifically recognizing GA3. Ru(bpy)32+ was used as probe and g-C3N4/Au was used as energy donor. The RET between Ru(bpy)32+ and g-C3N4/Au was used to enhance ECL intensity of Ru(bpy)32+. In addition, ECL-RET was combined with molecular imprinting technology to improve selectivity of the sensor. With the increase of the concentration of GA3, the molecularly imprinted cavities recombined with GA3, which made the ECL intensity gradually decreased. Under the optimized conditions, there was a linear relationship between ECL intensities and GA3 concentrations in the range from 4.00×10-14 mol/L to 7.00×10-11 mol/L, and the detection limit was 1.64×10-14 mol/L (3S/K). The sensor was successfully applied to the detection of GA3 in beer, and the recoveries were 95.7%-103.7%.
2020, 48(12): 1642-1649
doi: 10.19756/j.issn.0253-3820.201297
Abstract:
pH-sensitive material is commonly used as traditional freshness indicators, which is greatly suffered by environmental factors and easy to cause false positive results. To solve this problem, a freshness indicator using Meldrum's activated furan (MAF) as volatile amine-sensitive material and polyvinyl chloride (PVC) as supporting film was proposed in this work. MAF/PVC films were prepared by spin coating method, and the sensing properties of the films were investigated with NH3 as the model target. Experimental results showed that the film prepared with 15% mass content of MAF at 2000 r/min of coating speed revealed the best sensing property towards NH3. Using MAF/PVC film as the freshness indicator for fish, the lightness (L), redness (a) and yellowness (b) values of films were recorded. The color difference value (ΔE) was calculated according to the L, a, b values of the MAF/PVC films. At the same time, the TVB-N contents of fish samples were determined. Results showed that the trend of the ΔE value changes of the MAF/PVC film had a good correlation with the totla volatile basic nitrogen (TVB-N) content of the sample. Therefore, the freshness indicator based on MAF/PVC film could accurately and rapidly indicate the freshness of fish, thus showing a broad application prospect in detection of freshness of aquatic products.
pH-sensitive material is commonly used as traditional freshness indicators, which is greatly suffered by environmental factors and easy to cause false positive results. To solve this problem, a freshness indicator using Meldrum's activated furan (MAF) as volatile amine-sensitive material and polyvinyl chloride (PVC) as supporting film was proposed in this work. MAF/PVC films were prepared by spin coating method, and the sensing properties of the films were investigated with NH3 as the model target. Experimental results showed that the film prepared with 15% mass content of MAF at 2000 r/min of coating speed revealed the best sensing property towards NH3. Using MAF/PVC film as the freshness indicator for fish, the lightness (L), redness (a) and yellowness (b) values of films were recorded. The color difference value (ΔE) was calculated according to the L, a, b values of the MAF/PVC films. At the same time, the TVB-N contents of fish samples were determined. Results showed that the trend of the ΔE value changes of the MAF/PVC film had a good correlation with the totla volatile basic nitrogen (TVB-N) content of the sample. Therefore, the freshness indicator based on MAF/PVC film could accurately and rapidly indicate the freshness of fish, thus showing a broad application prospect in detection of freshness of aquatic products.
2020, 48(12): 1650-1657
doi: 10.19756/j.issn.0253-3820.201419
Abstract:
A ratiometric ascorbic acid (AA) electrochemical sensor was directly constructed by implanting thionine (Thi) on three-dimensional porous carbon derived from Kenaf stem (3D-KSC). The treated 3D-KSC and 3D-KSC/Thi were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). There were some micropores and defects situated in the wall of 3D-KSC's hole, which provided a large surface area and good catalytic activity. Owing to these pore defects, Thi molecules could adhere to its interior firmly. The 3D-KSC/Thi electrode had a catalytic effect against AA at 0.015 V ("on"), while the oxidation peak of Thi at -0.24 V did not change with the increase of concentration of AA ("off"), therefore, a ratiometric AA electrochemical sensor was designed by using the ratio of peak current density of these two oxidation peaks. The "on-off" ratiometric type of AA electrochemical sensor had high selectivity, wide linear detection (from 18.2 μmol/L to 8.0 mmol/L), low detection limit (6.0 μmol/L), and showed good potential application prospect.
A ratiometric ascorbic acid (AA) electrochemical sensor was directly constructed by implanting thionine (Thi) on three-dimensional porous carbon derived from Kenaf stem (3D-KSC). The treated 3D-KSC and 3D-KSC/Thi were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). There were some micropores and defects situated in the wall of 3D-KSC's hole, which provided a large surface area and good catalytic activity. Owing to these pore defects, Thi molecules could adhere to its interior firmly. The 3D-KSC/Thi electrode had a catalytic effect against AA at 0.015 V ("on"), while the oxidation peak of Thi at -0.24 V did not change with the increase of concentration of AA ("off"), therefore, a ratiometric AA electrochemical sensor was designed by using the ratio of peak current density of these two oxidation peaks. The "on-off" ratiometric type of AA electrochemical sensor had high selectivity, wide linear detection (from 18.2 μmol/L to 8.0 mmol/L), low detection limit (6.0 μmol/L), and showed good potential application prospect.
2020, 48(12): 1658-1665
doi: 10.19756/j.issn.0253-3820.201366
Abstract:
A system was set up for quantitative and qualitative analysis of outgassing of photoresists using pressure rise method. The outgassing of molecular glass photoresist films (Film A, B, C and D) based on 9, 9'-spirobifluorene (SP) derivatives was evaluated by the system. Film A was formed by SP with substituent group of tert-butyloxycarbonyl (Boc), and Film B and C were prepared by covering Film A with top-coating material in different thicknesses. Film D was formed by SP with substituent group of adamantyl acetate (Ad). The components of residual gas during the EUV irradiation were detected by the quadruple mass spectrometer (QMS). In the case of Film A, it showed that the source of the outgassing was mainly from the acid catalytic reaction of substituent of Boc group, releasing isobutylene (C4H8) and CO2 gas, along with a small amount of benzene component produced by the decomposition of photo acid generator (PAG). Film B and C, covered with protective layer, were similar to that of film A, but the ion abundance decreased obviously. Ion peak of CO2 molecule and the fragment peaks of adamantane substituent were observed in mass spectra of Film D. The amount of outgassing for different films was analyzed in-situ by an ion gauge, and it was found that the rate of outgassing was fast in the initial stage of exposure, and then slow down, suggesting that the molecules on the surface of the films were more likely to release gas. Besides, the top-coating could significantly reduce the rate of outgassing comparing the results of Film A and Film B/C, for instance, the outgassing could be reduced from 1.19×1015 molecule/cm2 to 2.35×1014 molecule/cm2 under the exposure dose of 10 mJ/cm2 by covering with 30-nm thickness of top-coating material, suggesting that the top-coating was an effective method to reduce outgassing. By comparing the outgassing of Film D and Film A that was formed by the resist materials with different peripheral substituent groups, it was found that the outgassing of Film D was decreased by 10 times than that of Film A, indicating that the substituent group of the photoresist materials had a significant effect on the outgassing, and the substituent group with higher molecular weight and thermal activation energy (Ea) was useful to reduce outgassing.
A system was set up for quantitative and qualitative analysis of outgassing of photoresists using pressure rise method. The outgassing of molecular glass photoresist films (Film A, B, C and D) based on 9, 9'-spirobifluorene (SP) derivatives was evaluated by the system. Film A was formed by SP with substituent group of tert-butyloxycarbonyl (Boc), and Film B and C were prepared by covering Film A with top-coating material in different thicknesses. Film D was formed by SP with substituent group of adamantyl acetate (Ad). The components of residual gas during the EUV irradiation were detected by the quadruple mass spectrometer (QMS). In the case of Film A, it showed that the source of the outgassing was mainly from the acid catalytic reaction of substituent of Boc group, releasing isobutylene (C4H8) and CO2 gas, along with a small amount of benzene component produced by the decomposition of photo acid generator (PAG). Film B and C, covered with protective layer, were similar to that of film A, but the ion abundance decreased obviously. Ion peak of CO2 molecule and the fragment peaks of adamantane substituent were observed in mass spectra of Film D. The amount of outgassing for different films was analyzed in-situ by an ion gauge, and it was found that the rate of outgassing was fast in the initial stage of exposure, and then slow down, suggesting that the molecules on the surface of the films were more likely to release gas. Besides, the top-coating could significantly reduce the rate of outgassing comparing the results of Film A and Film B/C, for instance, the outgassing could be reduced from 1.19×1015 molecule/cm2 to 2.35×1014 molecule/cm2 under the exposure dose of 10 mJ/cm2 by covering with 30-nm thickness of top-coating material, suggesting that the top-coating was an effective method to reduce outgassing. By comparing the outgassing of Film D and Film A that was formed by the resist materials with different peripheral substituent groups, it was found that the outgassing of Film D was decreased by 10 times than that of Film A, indicating that the substituent group of the photoresist materials had a significant effect on the outgassing, and the substituent group with higher molecular weight and thermal activation energy (Ea) was useful to reduce outgassing.
2020, 48(12): 1666-1673
doi: 10.19756/j.issn.0253-3820.201316
Abstract:
A facile emulsion self-assembly strategy by co-assembling oleylamine-coated gold nanoparticles (OA-AuNPs) with oleic acid-coated iron oxide nanoparticles (OC-IONPs) into polymer nanobeads to form magnetic coated gold nanoparticles (MGNPs) was reported. The synthesized MGNPs exhibited a typical "magnetic-coated gold" core-shell heterostructure. Due to that OA-AuNPs aggregated in core and OC-IONPs assembled in shell, the magnetic shielding effect of OA-AuNPs was effectively avoided. Therefore, compared with the traditional "gold-coated magnetic" nanostructures, the MGNPs synthesized here had higher magnetic saturation intensity (80% of OC-IONPs) and strong absorbance (12.5 times that of the traditional 30 nm colloidal gold nanoparticles). By using MGNPs as the dual-function labeled probe and human chorionic gonadotropin (HCG) as a model biomarker, a highly sensitive immunochromatographic method (MGNPs-ICA) for detecting biomarkers in human serum was established. The results showed that the linear range of the MGNPs-ICA strip for quantitative detection of HCG in human serum was 0.97-250 mIU/mL, and the linear regression equation was y=0.2561lnx-0.0429 (R2=0.9816). The detection limit was 0.97 mIU/mL. The intra-and inter-assay recoveries for HCG spiked serum were 93.7%-109.1%, and the coefficient of variation was less than 14.3%. The specific experimental results showed that the method only showed a significant signal response to target HCG. In addition, the results of this method were in good agreement with those of chemiluminescence immunoassay (CLIA). Compared with CLIA method, MGNPs-ICA method had significant advantages in detection time, cost and portability. In a word, the as-prepared MGNPs had excellent magnetic properties and strong optical sensing ability, and could significantly improve the detection performance of ICA platform.
A facile emulsion self-assembly strategy by co-assembling oleylamine-coated gold nanoparticles (OA-AuNPs) with oleic acid-coated iron oxide nanoparticles (OC-IONPs) into polymer nanobeads to form magnetic coated gold nanoparticles (MGNPs) was reported. The synthesized MGNPs exhibited a typical "magnetic-coated gold" core-shell heterostructure. Due to that OA-AuNPs aggregated in core and OC-IONPs assembled in shell, the magnetic shielding effect of OA-AuNPs was effectively avoided. Therefore, compared with the traditional "gold-coated magnetic" nanostructures, the MGNPs synthesized here had higher magnetic saturation intensity (80% of OC-IONPs) and strong absorbance (12.5 times that of the traditional 30 nm colloidal gold nanoparticles). By using MGNPs as the dual-function labeled probe and human chorionic gonadotropin (HCG) as a model biomarker, a highly sensitive immunochromatographic method (MGNPs-ICA) for detecting biomarkers in human serum was established. The results showed that the linear range of the MGNPs-ICA strip for quantitative detection of HCG in human serum was 0.97-250 mIU/mL, and the linear regression equation was y=0.2561lnx-0.0429 (R2=0.9816). The detection limit was 0.97 mIU/mL. The intra-and inter-assay recoveries for HCG spiked serum were 93.7%-109.1%, and the coefficient of variation was less than 14.3%. The specific experimental results showed that the method only showed a significant signal response to target HCG. In addition, the results of this method were in good agreement with those of chemiluminescence immunoassay (CLIA). Compared with CLIA method, MGNPs-ICA method had significant advantages in detection time, cost and portability. In a word, the as-prepared MGNPs had excellent magnetic properties and strong optical sensing ability, and could significantly improve the detection performance of ICA platform.
2020, 48(12): 1674-1680
doi: 10.19756/j.issn.0253-3820.191705
Abstract:
A novel antibacterial material of Ag nanoclusters hydrogel using silver nitrate and L-cysteine as raw materials was prepared by ultraviolet light reduction method. The structure and morphology of the material were characterized by transmission electron microscope (TEM), X-ray photoelectron spectra (XPS), scanning electron microscope (SEM) and X ray energy spectrum analysis (EDS). The antimicrobial properties of Ag nanoclusters hydrogel against sulfate reducing bacteria (SRB) were further studied through the minimum inhibitory concentration (MIC), the minimum bactericidal concentration (MBC), growth curve and bacterial staining experiment using anaerobic workstations. The results indicated that, compared with the conventional inorganic antibacterial material sodium hypochlorite, the prepared Ag nanoclusters hydrogel had excellent antibacterial effect on SRB, and the MIC and MBC against SRB were 18.75 μg/mL and 37.5 μg/mL, respectively.
A novel antibacterial material of Ag nanoclusters hydrogel using silver nitrate and L-cysteine as raw materials was prepared by ultraviolet light reduction method. The structure and morphology of the material were characterized by transmission electron microscope (TEM), X-ray photoelectron spectra (XPS), scanning electron microscope (SEM) and X ray energy spectrum analysis (EDS). The antimicrobial properties of Ag nanoclusters hydrogel against sulfate reducing bacteria (SRB) were further studied through the minimum inhibitory concentration (MIC), the minimum bactericidal concentration (MBC), growth curve and bacterial staining experiment using anaerobic workstations. The results indicated that, compared with the conventional inorganic antibacterial material sodium hypochlorite, the prepared Ag nanoclusters hydrogel had excellent antibacterial effect on SRB, and the MIC and MBC against SRB were 18.75 μg/mL and 37.5 μg/mL, respectively.
2020, 48(12): 1681-1686
doi: 10.19756/j.issn.0253-3820.201084
Abstract:
Host-guest interaction of cucurbit[10]uril (Q[10] or CB[10]) with pyrene-derived derivatives was evaluated by fluorescence emission spectra and UV-vis absorption spectra, and the host-guest binding modes were studied by density functional theory (DFT). In the energy minimization structures, the pyrene group of the guest was encapsulated in the larger hydrophobic cavity of Q[10] in parallel from the opposite direction in the form of a head-to-head fashion, forming a 2∶1 inclusion. The thermodynamic data indicated that the two host-guest interactions were enthalpy-driven. Furthermore, the Q[10] host-guest interaction of Q[10]/G2 could be used as ratiometric fluorescent probe based on the unique monomer/excimer emission of pyrene moiety on the guest G2. Experiment results indicated that the host-guest interaction derived probe had good recognition and selectivity for nilotinib in aqueous solution, and the detection limit was 7.05 μmol/L.
Host-guest interaction of cucurbit[10]uril (Q[10] or CB[10]) with pyrene-derived derivatives was evaluated by fluorescence emission spectra and UV-vis absorption spectra, and the host-guest binding modes were studied by density functional theory (DFT). In the energy minimization structures, the pyrene group of the guest was encapsulated in the larger hydrophobic cavity of Q[10] in parallel from the opposite direction in the form of a head-to-head fashion, forming a 2∶1 inclusion. The thermodynamic data indicated that the two host-guest interactions were enthalpy-driven. Furthermore, the Q[10] host-guest interaction of Q[10]/G2 could be used as ratiometric fluorescent probe based on the unique monomer/excimer emission of pyrene moiety on the guest G2. Experiment results indicated that the host-guest interaction derived probe had good recognition and selectivity for nilotinib in aqueous solution, and the detection limit was 7.05 μmol/L.
2020, 48(12): 1687-1693
doi: 10.19756/j.issn.0253-3820.201306
Abstract:
Optical nanoprobes have attracted extensive attention in area of analytical chemistry because of their unique structural characteristics and optical properties. In this study, a novel fluorescence/surface-enhanced Raman scattering (SERS) dual-modal nanoprobe was developed. The phenolic hydroxyl group and Schiff base of hydroxybenzoic acid derivative (NAMH) exhibited a preferential affinity towards Zn2+. The complexation between AgNPs@NAMH and Zn2+ induced the quenching of the fluorescent signal of NAMH, thus enabling the fluorescent detection of Zn2+ in complex samples with a detection limit of 0.32 nmol/L. Moreover, the Zn2+-triggered AgNPs aggregation led to the formation of abundant "hot spots" among NPs, which could be used for SERS analysis of Zn2+ with a detection limit of 0.68 pmol/L. This method had a number of advantages over conventional approaches in simplicity of operation, rapidity, high sensitivity and high selectivity, and provided new technical support for the immediate detection of environmental pollutants.
Optical nanoprobes have attracted extensive attention in area of analytical chemistry because of their unique structural characteristics and optical properties. In this study, a novel fluorescence/surface-enhanced Raman scattering (SERS) dual-modal nanoprobe was developed. The phenolic hydroxyl group and Schiff base of hydroxybenzoic acid derivative (NAMH) exhibited a preferential affinity towards Zn2+. The complexation between AgNPs@NAMH and Zn2+ induced the quenching of the fluorescent signal of NAMH, thus enabling the fluorescent detection of Zn2+ in complex samples with a detection limit of 0.32 nmol/L. Moreover, the Zn2+-triggered AgNPs aggregation led to the formation of abundant "hot spots" among NPs, which could be used for SERS analysis of Zn2+ with a detection limit of 0.68 pmol/L. This method had a number of advantages over conventional approaches in simplicity of operation, rapidity, high sensitivity and high selectivity, and provided new technical support for the immediate detection of environmental pollutants.
2020, 48(12): 1694-1700
doi: 10.19756/j.issn.0253-3820.201462
Abstract:
Core-shell chloramphenicol (CAP) molecularly imprinted polymer was prepared by sol-gel method with chloramphenicol as template molecule and metal-organic framework material MIL-101 as substrate. The structure and morphology of MIL-101 and molecularly imprinted polymer were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that MIL-101 had a regular octahedral structure, and the surface was covered with ordered and porous imprinted polymers. The kinetics and selective adsorption properties of molecularly imprinted polymers were tested. The maximum adsorption capacity of the imprinted polymer was 66.56 mg/g, and the adsorption equilibrium reached within 22.5 min. The imprinted polymer had high selective recognition ability to chloramphenicol. The molecularly imprinted polymers were used as solid phase extraction filler for analysis of chloramphenicol in aquatic products by HPLC method, with recoveries of 75.0%-103.7% and relative standard deviations of 1.2%-3.9% (n=5).
Core-shell chloramphenicol (CAP) molecularly imprinted polymer was prepared by sol-gel method with chloramphenicol as template molecule and metal-organic framework material MIL-101 as substrate. The structure and morphology of MIL-101 and molecularly imprinted polymer were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that MIL-101 had a regular octahedral structure, and the surface was covered with ordered and porous imprinted polymers. The kinetics and selective adsorption properties of molecularly imprinted polymers were tested. The maximum adsorption capacity of the imprinted polymer was 66.56 mg/g, and the adsorption equilibrium reached within 22.5 min. The imprinted polymer had high selective recognition ability to chloramphenicol. The molecularly imprinted polymers were used as solid phase extraction filler for analysis of chloramphenicol in aquatic products by HPLC method, with recoveries of 75.0%-103.7% and relative standard deviations of 1.2%-3.9% (n=5).
2020, 48(12): 1701-1708
doi: 10.19756/j.issn.0253-3820.201072
Abstract:
An aptamer-based electrochemical biosensor was developed for detection of cadmium ions (Cd2+). Firstly, the mercapto-modified complementary sequence (CDNA) of aptamer was immobilized on the electrode surface via AuS bond. Then, it hybridized with aptamer to form a double-stranded DNA. Due to the specific binding of aptamer and Cd2+, the aptamer labeled with ferrocene was competed off the gold electrode, so that the electrochemical signal of ferrocene decreased significantly. By using square wave voltammetry (SWV) detection and under the optimal conditions, a linear relationship was found between the current signal and logarithm of Cd2+ concentration with an equation of ΔI=0.2827+0.2372lgC (R2=0.9972), where the linearity range was from 1.0 nmol/L to 10.0 μmol/L, with a detection limit of 65.1 pmol/L, and the recoveries in real river samples were 97.1%-97.9%, which was comparable to those measured by graphite furnace atomic absorption spectrometry. The proposed method displayed many advantages such as high sensitivity, fast detection and excellent specificity, and had a good application prospect in monitoring cadmium pollution.
An aptamer-based electrochemical biosensor was developed for detection of cadmium ions (Cd2+). Firstly, the mercapto-modified complementary sequence (CDNA) of aptamer was immobilized on the electrode surface via AuS bond. Then, it hybridized with aptamer to form a double-stranded DNA. Due to the specific binding of aptamer and Cd2+, the aptamer labeled with ferrocene was competed off the gold electrode, so that the electrochemical signal of ferrocene decreased significantly. By using square wave voltammetry (SWV) detection and under the optimal conditions, a linear relationship was found between the current signal and logarithm of Cd2+ concentration with an equation of ΔI=0.2827+0.2372lgC (R2=0.9972), where the linearity range was from 1.0 nmol/L to 10.0 μmol/L, with a detection limit of 65.1 pmol/L, and the recoveries in real river samples were 97.1%-97.9%, which was comparable to those measured by graphite furnace atomic absorption spectrometry. The proposed method displayed many advantages such as high sensitivity, fast detection and excellent specificity, and had a good application prospect in monitoring cadmium pollution.
2020, 48(12): 1709-1716
doi: 10.19756/j.issn.0253-3820.201401
Abstract:
In this study, 10 saliva samples were used as data sets. After the saliva sample was separated by graphene oxide-lanthanum phosphate nanocomposite (LaGM) method and identified by high-resolution tandem time-of-flight mass spectrometry, Peaks studio 8.5 (PS) and Protein Pilot Software 4.0 (PP) were used for searching analysis and the identification results were compared. It was found that the number of peptides identified by the two softwares were different. Under the experimental conditions, not only the PS software could usually identify more peptides, but also the results given by the two softwares did not completely overlap, and the same peptides identified by the two softwares occupied 30%-60% in PS and 60%-90% in PP, which meant that some peptides could be only identified by PS or PP software, but at the level of degraded protein, PS method had no obvious advantages. It was worth noting that if the positive results of PP and PS were cross-referenced, peptides below the threshold in one software may be above the threshold in another software, and this probability was positive related to the score of the peptide. Further research also found that the two softwares had a certain preference for identifying peptides of different lengths. The identified results of PS had more short peptides, while PP software could give more long peptides. In comparison, in PP software, short peptides were prone to false negative result, but long peptides were prone to false negative result in PS software. And the intensity of the signal had no obvious correlation with the threshold. This study showed that it was not advisable to use only one kind of software to analyze or only use the same reference result to represent the entire peptidome. Both softwares could identify the information each other that could not be identified by the other software. Cross-referencing the two analysis softwares each other could improve the accuracy of the results.
In this study, 10 saliva samples were used as data sets. After the saliva sample was separated by graphene oxide-lanthanum phosphate nanocomposite (LaGM) method and identified by high-resolution tandem time-of-flight mass spectrometry, Peaks studio 8.5 (PS) and Protein Pilot Software 4.0 (PP) were used for searching analysis and the identification results were compared. It was found that the number of peptides identified by the two softwares were different. Under the experimental conditions, not only the PS software could usually identify more peptides, but also the results given by the two softwares did not completely overlap, and the same peptides identified by the two softwares occupied 30%-60% in PS and 60%-90% in PP, which meant that some peptides could be only identified by PS or PP software, but at the level of degraded protein, PS method had no obvious advantages. It was worth noting that if the positive results of PP and PS were cross-referenced, peptides below the threshold in one software may be above the threshold in another software, and this probability was positive related to the score of the peptide. Further research also found that the two softwares had a certain preference for identifying peptides of different lengths. The identified results of PS had more short peptides, while PP software could give more long peptides. In comparison, in PP software, short peptides were prone to false negative result, but long peptides were prone to false negative result in PS software. And the intensity of the signal had no obvious correlation with the threshold. This study showed that it was not advisable to use only one kind of software to analyze or only use the same reference result to represent the entire peptidome. Both softwares could identify the information each other that could not be identified by the other software. Cross-referencing the two analysis softwares each other could improve the accuracy of the results.
2020, 48(12): 1717-1727
doi: 10.19756/j.issn.0253-3820.201485
Abstract:
Peucedani radix and other herbal medicines are not only complex in chemical composition, but also often contain a large number of enantiomers, and there are often differences in content of enantiomers. In this work, a new analytical platform namely achiral-chiral liquid chromatography (LC)-predictive multiple reaction monitoring was firstly configured for chemo- and enantio-selective separation of the components in Peucedani Radix, a well-known herbal medicine. Serially coupled achiral LC and chiral LC integrated the robust separation potential of RP-C18 column along with the enantio-separation advantage from chiral column, thus addressing the disadvantages of heart-cutting achiral-chiral two dimensional LC in terms of sophisticated instrumentation and unsatisfactory precision. The narrow-bore core-shell RP-C18 column was served as the front tool to accomplish efficient chemo-selective separation within those coumarins bearing similar chemical structures, a dilution pump was introduced between the two columns to facilitate the optimization of optimum elution program from the chiral column, and a wide-bore chiral column offered the enantio-separation potential for those enantiomers. Predictive MRM mode was deployed to sensitively detect the chemical components, and the enhanced product ion program was utilized to acquire MS2 spectra for all signals. Structure confirmation was conducted by matching the fragment ion species with the well-proposed fragmentation rules. As a result, 61 components, in total, were found from Peucedani Radix, including eleven pairs of enantiomers. Above all, achiral-chiral LC-predictive MRM is a promising tool for the quantitative and qualitative analysis of the complicated matrices, beyond herbal medicines, which are featured by enantiomerically enriched mixtures.
Peucedani radix and other herbal medicines are not only complex in chemical composition, but also often contain a large number of enantiomers, and there are often differences in content of enantiomers. In this work, a new analytical platform namely achiral-chiral liquid chromatography (LC)-predictive multiple reaction monitoring was firstly configured for chemo- and enantio-selective separation of the components in Peucedani Radix, a well-known herbal medicine. Serially coupled achiral LC and chiral LC integrated the robust separation potential of RP-C18 column along with the enantio-separation advantage from chiral column, thus addressing the disadvantages of heart-cutting achiral-chiral two dimensional LC in terms of sophisticated instrumentation and unsatisfactory precision. The narrow-bore core-shell RP-C18 column was served as the front tool to accomplish efficient chemo-selective separation within those coumarins bearing similar chemical structures, a dilution pump was introduced between the two columns to facilitate the optimization of optimum elution program from the chiral column, and a wide-bore chiral column offered the enantio-separation potential for those enantiomers. Predictive MRM mode was deployed to sensitively detect the chemical components, and the enhanced product ion program was utilized to acquire MS2 spectra for all signals. Structure confirmation was conducted by matching the fragment ion species with the well-proposed fragmentation rules. As a result, 61 components, in total, were found from Peucedani Radix, including eleven pairs of enantiomers. Above all, achiral-chiral LC-predictive MRM is a promising tool for the quantitative and qualitative analysis of the complicated matrices, beyond herbal medicines, which are featured by enantiomerically enriched mixtures.
2020, 48(12): 1728-1736
doi: 10.19756/j.issn.0253-3820.201361
Abstract:
Egg preservation is of importance factor in the process of storage and transportation. To explore the effect of carbon dioxide on the storage quality and extend the shelf-life of eggs, fresh eggs, as the research subject in the study, were stored in the storage boxes with CO2 at concentration of 0.03% (Air concentration), 5%, 10% and 20% (Divided into Group A, Group B, Group C and Group D, respectively). Furthermore, the study had an investigation into the impacts of CO2 on the respiration intensity and freshness of eggs as well as the Grey Relational Analysis between index values and respiration intensity, which would provide theoretical support for egg storage, transportation and preservation. Under the general environment (25℃ and 65% humidity), the respiration of eggs in Group B, C and D were inhibited and the respiration intensity were weak, while the respiration intensity of Group A gradually decreased from strong to weak over time. The pH value of Group A was higher than the other three groups. The colonies formed in 5 days in Group A and in 15 days in the other three groups. Colonies count in Group A was about 60 times of that of the other three groups after storage for 45 days. In comparison with Group A, the rates of decrease of the egg Haugh units and egg yolk index in Group B, C and D were gentler, and the shelf-life of Group A was longer than that of Group B, C and D. In a word, the CO2 at concentration of over 5% could effectively inhibit the respiration of eggs so as to achieve bacteriostat and preservation, and the most suitable CO2 concentration was 10% among the four groups. There was a strong correlation between the respiration intensity and Haugh unit, yolk index as well as pH value, and the colonies count had the least effect on the respiration intensity.
Egg preservation is of importance factor in the process of storage and transportation. To explore the effect of carbon dioxide on the storage quality and extend the shelf-life of eggs, fresh eggs, as the research subject in the study, were stored in the storage boxes with CO2 at concentration of 0.03% (Air concentration), 5%, 10% and 20% (Divided into Group A, Group B, Group C and Group D, respectively). Furthermore, the study had an investigation into the impacts of CO2 on the respiration intensity and freshness of eggs as well as the Grey Relational Analysis between index values and respiration intensity, which would provide theoretical support for egg storage, transportation and preservation. Under the general environment (25℃ and 65% humidity), the respiration of eggs in Group B, C and D were inhibited and the respiration intensity were weak, while the respiration intensity of Group A gradually decreased from strong to weak over time. The pH value of Group A was higher than the other three groups. The colonies formed in 5 days in Group A and in 15 days in the other three groups. Colonies count in Group A was about 60 times of that of the other three groups after storage for 45 days. In comparison with Group A, the rates of decrease of the egg Haugh units and egg yolk index in Group B, C and D were gentler, and the shelf-life of Group A was longer than that of Group B, C and D. In a word, the CO2 at concentration of over 5% could effectively inhibit the respiration of eggs so as to achieve bacteriostat and preservation, and the most suitable CO2 concentration was 10% among the four groups. There was a strong correlation between the respiration intensity and Haugh unit, yolk index as well as pH value, and the colonies count had the least effect on the respiration intensity.
2020, 48(12): 1737-1746
doi: 10.19756/j.issn.0253-3820.191289
Abstract:
Hyperspectral imaging technology enables rapid non-destructive inspection and grading of various agricultural products. In this work, the research on the quality detection method of walnut kernel based on hyperspectral image was carried out. The combination of spectrum and image information was used to realize the prediction of protein and fat content and the classification of the integrity and color of walnut kernel. The "Wen 185" walnuts, which were produced from Xinjiang, were shelled and prepared by different grades of integrity and color. Then the hyperspectral image of each sample was measured in the range of 862.9-1704.02 nm and 382.19-1026.66 nm by Gaia hyperspectral imager. After that, the color difference, fat content and protein content of samples were measured. Multivariate scatter correction and standard normalized variate were used to pre-processing the original spectral information. And the feature bands were screened by the method, which combined competitive adaptive re-weighting sampling (CARS) and correlation coefficient method (CCM ) algorithm, for the three parameters of protein content, fat content and total color difference of walnut kernel samples. Six feature bands related to protein content and 7 feature bands related to fat content were screened out. The internal quality parameter prediction model of the full spectrum band and the characteristic spectrum band were established by partial least squares regression (PLSR) algorithm. Compared with the full-spectrum band, the verification set coefficient (R2) of the feature band protein content prediction model increased from 0.66 to 0.91, and the mean square error (RMSEP) decreased from 1.37% to 0.78%. The verification set coefficient (R2) of the feature band fat content prediction model increased from 0.83 to 0.93, and the RMSEP decreased from 0.98% to 0.47%. It showed that the selected characteristic bands effectively reduced the complexity of the full spectrum information and improved the quality of modeling. In terms of appearance quality, the feature bands associating with the color difference were selected to be 402.5 and 689.2 nm. The full-spectral spectrum, RGB spectrum, characteristic spectrum and the combination of spectral and image information were used to establish the walnut appearance quality classification model by decision tree, K-nearest neighbor and support vector machine algorithm. It showed that the feature bands modeling greatly reduced the interference of redundant information, improved the modeling efficiency, and the classification accuracy were also significantly higher than the RGB bands by comparison. The adding image statistical feature parameter to the feature bands and RGB bands could further improve the accuracy of classification model which had the highest classification accuracy rate reached to 98.6% by decision tree algorithm. In terms of classification algorithm, the decision tree algorithm had obvious advantages in classification accuracy and calculation speed when the number of input variables was less. The used of hyperspectral technology could realize the internal quality detection and appearance classification of walnut kernels, which provided a new theoretical basis for the application of non-destructive testing of walnut kernel quality.
Hyperspectral imaging technology enables rapid non-destructive inspection and grading of various agricultural products. In this work, the research on the quality detection method of walnut kernel based on hyperspectral image was carried out. The combination of spectrum and image information was used to realize the prediction of protein and fat content and the classification of the integrity and color of walnut kernel. The "Wen 185" walnuts, which were produced from Xinjiang, were shelled and prepared by different grades of integrity and color. Then the hyperspectral image of each sample was measured in the range of 862.9-1704.02 nm and 382.19-1026.66 nm by Gaia hyperspectral imager. After that, the color difference, fat content and protein content of samples were measured. Multivariate scatter correction and standard normalized variate were used to pre-processing the original spectral information. And the feature bands were screened by the method, which combined competitive adaptive re-weighting sampling (CARS) and correlation coefficient method (CCM ) algorithm, for the three parameters of protein content, fat content and total color difference of walnut kernel samples. Six feature bands related to protein content and 7 feature bands related to fat content were screened out. The internal quality parameter prediction model of the full spectrum band and the characteristic spectrum band were established by partial least squares regression (PLSR) algorithm. Compared with the full-spectrum band, the verification set coefficient (R2) of the feature band protein content prediction model increased from 0.66 to 0.91, and the mean square error (RMSEP) decreased from 1.37% to 0.78%. The verification set coefficient (R2) of the feature band fat content prediction model increased from 0.83 to 0.93, and the RMSEP decreased from 0.98% to 0.47%. It showed that the selected characteristic bands effectively reduced the complexity of the full spectrum information and improved the quality of modeling. In terms of appearance quality, the feature bands associating with the color difference were selected to be 402.5 and 689.2 nm. The full-spectral spectrum, RGB spectrum, characteristic spectrum and the combination of spectral and image information were used to establish the walnut appearance quality classification model by decision tree, K-nearest neighbor and support vector machine algorithm. It showed that the feature bands modeling greatly reduced the interference of redundant information, improved the modeling efficiency, and the classification accuracy were also significantly higher than the RGB bands by comparison. The adding image statistical feature parameter to the feature bands and RGB bands could further improve the accuracy of classification model which had the highest classification accuracy rate reached to 98.6% by decision tree algorithm. In terms of classification algorithm, the decision tree algorithm had obvious advantages in classification accuracy and calculation speed when the number of input variables was less. The used of hyperspectral technology could realize the internal quality detection and appearance classification of walnut kernels, which provided a new theoretical basis for the application of non-destructive testing of walnut kernel quality.
2020, 48(12): 1747-1752
doi: 10.19756/j.issn.0253-3820.201460
Abstract:
Surface-enhanced Raman spectroscopy (SERS) can obtain highly sensitive structural information of substances with ultralow concentration or even at the single-molecule level. Herein, a rapid detection method for triadimenol and triadimefon in raw tobacco was established using SERS combined with portable Raman spectrometer. In this method, polyamide under acidic conditions was used as a purifying agent to remove the interference from pigments, phenols, organic acids and other impurities in tobacco. Gold-based SERS substrates were used to amplify the Raman signals through the adsorption of triadimenol and triadimefon on the surface of gold nanoparticles. It was found that the detection sensitivity of triadimenol and triadimefon residues in raw tobacco was 1 mg/kg, and the time needed was 8-12 min. This method was simple, low-cost, and accurate, thus was suitable for the rapid detection of triadimenol and triadimefon pesticide residues in tobacco.
Surface-enhanced Raman spectroscopy (SERS) can obtain highly sensitive structural information of substances with ultralow concentration or even at the single-molecule level. Herein, a rapid detection method for triadimenol and triadimefon in raw tobacco was established using SERS combined with portable Raman spectrometer. In this method, polyamide under acidic conditions was used as a purifying agent to remove the interference from pigments, phenols, organic acids and other impurities in tobacco. Gold-based SERS substrates were used to amplify the Raman signals through the adsorption of triadimenol and triadimefon on the surface of gold nanoparticles. It was found that the detection sensitivity of triadimenol and triadimefon residues in raw tobacco was 1 mg/kg, and the time needed was 8-12 min. This method was simple, low-cost, and accurate, thus was suitable for the rapid detection of triadimenol and triadimefon pesticide residues in tobacco.
