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2023 Volume 51 Issue 2
2023, 51(2): 147-159
doi: 10.19756/j.issn.0253-3820.221424
Abstract:
Metal-organic frameworks (MOFs), which are self-assembled by metal ions and organic ligands through coordination chemistry, have periodically lattice crystalline porous structure, and have been widely used as materials due to their unique structures and properties. Because MOFs can greatly improve the target enrichment and signal enhancement performance of metal surface-enhanced Raman spectroscopy (SERS) substrates, MOFsbased SERS substrates have attracted much attention. The efficient SERS substrate enables SERS technology achieves high sensitivity, high selectivity, nondestructive and rapid detection. The advantages of MOFs and SERS greatly promote the development of SERS technology and widen its application range. In this review, the development of SERS, MOFs based substrate categories and their applications in SERS were reviewed, the key issues to be solved urgently and challenges were discussed, and the future development trend was prospected.
Metal-organic frameworks (MOFs), which are self-assembled by metal ions and organic ligands through coordination chemistry, have periodically lattice crystalline porous structure, and have been widely used as materials due to their unique structures and properties. Because MOFs can greatly improve the target enrichment and signal enhancement performance of metal surface-enhanced Raman spectroscopy (SERS) substrates, MOFsbased SERS substrates have attracted much attention. The efficient SERS substrate enables SERS technology achieves high sensitivity, high selectivity, nondestructive and rapid detection. The advantages of MOFs and SERS greatly promote the development of SERS technology and widen its application range. In this review, the development of SERS, MOFs based substrate categories and their applications in SERS were reviewed, the key issues to be solved urgently and challenges were discussed, and the future development trend was prospected.
2023, 51(2): 160-171
doi: 10.19756/j.issn.0253-3820.221312
Abstract:
Metal-organic gels (MOGs) are a kind of gel material formed by bridging metal ions and organic ligands via non covalent interactions. In comparison with metal-organic frameworks (MOFs) that require timeconsuming preparation, MOGs can be obtained by self-assembling through the coordination under mild conditions to form porous supramolecular structure via hydrogen bonding interactions, π-π stacking and van der Waals forces. MOGs possess good surface accessibility, high surface area, and multiple stimuli-responsive properties. Due to the easy preparation and large specific surface area, tunable structure, and abundant metal sites, MOGs are widely used in the fields of sensing and analysis, and also show unique advantages in the fields of catalysis, adsorption, energy storage and electrochromic devices. In this paper, the research and application progress of MOGs in the above fields in recent years is reviewed, and the challenges, future trends and application prospects are discussed.
Metal-organic gels (MOGs) are a kind of gel material formed by bridging metal ions and organic ligands via non covalent interactions. In comparison with metal-organic frameworks (MOFs) that require timeconsuming preparation, MOGs can be obtained by self-assembling through the coordination under mild conditions to form porous supramolecular structure via hydrogen bonding interactions, π-π stacking and van der Waals forces. MOGs possess good surface accessibility, high surface area, and multiple stimuli-responsive properties. Due to the easy preparation and large specific surface area, tunable structure, and abundant metal sites, MOGs are widely used in the fields of sensing and analysis, and also show unique advantages in the fields of catalysis, adsorption, energy storage and electrochromic devices. In this paper, the research and application progress of MOGs in the above fields in recent years is reviewed, and the challenges, future trends and application prospects are discussed.
2023, 51(2): 172-183
doi: 10.19756/j.issn.0253-3820.221328
Abstract:
Nanomaterial-based laser desorption/ionization mass spectrometry (LDI-MS) technique has emerged and bloomed in recent years. Taking the advantages of nanomaterials, including high laser desorption and transfer efficiency, large specific surface area, and inert ionization, LDI-MS owned the cutting-edge advances such as high sensitivity, speediness, high throughput, and clean spectrum background. This review summarizes the application advances of nanomaterials in LDI-MS in biomedical analysis over the past 10 years, categorized by carbon-based nanomaterials, silicon-based nanomaterials, metal-organic frameworks, covalent organic frameworks, and metalbased nanomaterials. It compares the influence of different functionalization or composite material on the issues containing sensitivity and analyte kinds, and briefly illustrates the application of various nanomaterials on mass spectrometric imaging techniques that focuses on the applicability of the spatial distribution of internal and external metabolites. Finally, the key issues and prospects of this field are depicted.
Nanomaterial-based laser desorption/ionization mass spectrometry (LDI-MS) technique has emerged and bloomed in recent years. Taking the advantages of nanomaterials, including high laser desorption and transfer efficiency, large specific surface area, and inert ionization, LDI-MS owned the cutting-edge advances such as high sensitivity, speediness, high throughput, and clean spectrum background. This review summarizes the application advances of nanomaterials in LDI-MS in biomedical analysis over the past 10 years, categorized by carbon-based nanomaterials, silicon-based nanomaterials, metal-organic frameworks, covalent organic frameworks, and metalbased nanomaterials. It compares the influence of different functionalization or composite material on the issues containing sensitivity and analyte kinds, and briefly illustrates the application of various nanomaterials on mass spectrometric imaging techniques that focuses on the applicability of the spatial distribution of internal and external metabolites. Finally, the key issues and prospects of this field are depicted.
2023, 51(2): 184-193
doi: 10.19756/j.issn.0253-3820.221203
Abstract:
A CRISPR/Cas12a-based biosensor using molecular beacon (MB) as the reporter was constructed for amplification detection of circular tumor DNA (ctDNA). The molecular beacon with good stability was labeled with FAM and TAMRA at its ends, respectively. In the absence of ctDNA, the CRISPR/Cas12a system was inactive and MB could not be cleaved. Therefore, two fluorophores were in close proximity to each other, resulting in fluorescence resonance energy transfer (FRET). In the presence of ctDNA, it could recognize the Cas12a/crRNA complex and activate the trans-cleavage activity of Cas12a. Because ssDNA was the most susceptible substrate of Cas12a, the loop of MB was rapidly cleaved first. After cleavage, two fluorophores were far from each other, leading to the disappearance of FRET phenomenon and an obvious fluorescent enhancement of FAM. The experimental conditions such as the base numbers of the hairpin loop, the concentration of MB, and the concentration ratio of crRNA to Cas12a were optimized. Under the optimal conditions, a linear relationship ranging from 1.7 pmol/L to 500 pmol/L for ctDNA quantitative detection was observed and its detection limit was 600 fmol/L. In addition, this sensor could be used to detect ctDNA in serum samples and the recoveries were in the range of 93%-110%.
A CRISPR/Cas12a-based biosensor using molecular beacon (MB) as the reporter was constructed for amplification detection of circular tumor DNA (ctDNA). The molecular beacon with good stability was labeled with FAM and TAMRA at its ends, respectively. In the absence of ctDNA, the CRISPR/Cas12a system was inactive and MB could not be cleaved. Therefore, two fluorophores were in close proximity to each other, resulting in fluorescence resonance energy transfer (FRET). In the presence of ctDNA, it could recognize the Cas12a/crRNA complex and activate the trans-cleavage activity of Cas12a. Because ssDNA was the most susceptible substrate of Cas12a, the loop of MB was rapidly cleaved first. After cleavage, two fluorophores were far from each other, leading to the disappearance of FRET phenomenon and an obvious fluorescent enhancement of FAM. The experimental conditions such as the base numbers of the hairpin loop, the concentration of MB, and the concentration ratio of crRNA to Cas12a were optimized. Under the optimal conditions, a linear relationship ranging from 1.7 pmol/L to 500 pmol/L for ctDNA quantitative detection was observed and its detection limit was 600 fmol/L. In addition, this sensor could be used to detect ctDNA in serum samples and the recoveries were in the range of 93%-110%.
2023, 51(2): 194-203
doi: 10.19756/j.issn.0253-3820.221482
Abstract:
Formaldehyde is a kind of colorless and odorless carcinogen that can cause many diseases. It is very necessary to develope a simple and sensitive detection method for formaldehyde in environmental monitoring, toxicological assessment, clinical diagnosis and medical care. Herein, a new fluorescence detection method was developed based on the aggregation-induced emission (AIE) effect for aqueous formaldehyde. An AIE probe of tetra (4-hydroxyphenyl) ethylene (TPE-4OH) was synthesized, which could react with formaldehyde by Mannich reaction in the presence of 1,2,4,5-benzenetetramine tetrahydrochloride (BTA), causing an obvious enhancement of fluorescence of TPE-4OH. Due to the fluorescence enhancement of TPE-4OH related to the Mannich reaction and the concentration of formaldehyde, the detection of formaldehyde in the aqueous solution could be realized by measuring the fluorescence intensity of TPE-4OH. By optimizing the conditions of reactant concentration, solution pH value and reaction time, the linear range of detection of formaldehyde was from 1.0 μmol/L to 2000 μmol/L, and the detection limit was 1.0 μmol/L. The results showed that this method had the potential in sensing/diagnosis applications of formaldehyde.
Formaldehyde is a kind of colorless and odorless carcinogen that can cause many diseases. It is very necessary to develope a simple and sensitive detection method for formaldehyde in environmental monitoring, toxicological assessment, clinical diagnosis and medical care. Herein, a new fluorescence detection method was developed based on the aggregation-induced emission (AIE) effect for aqueous formaldehyde. An AIE probe of tetra (4-hydroxyphenyl) ethylene (TPE-4OH) was synthesized, which could react with formaldehyde by Mannich reaction in the presence of 1,2,4,5-benzenetetramine tetrahydrochloride (BTA), causing an obvious enhancement of fluorescence of TPE-4OH. Due to the fluorescence enhancement of TPE-4OH related to the Mannich reaction and the concentration of formaldehyde, the detection of formaldehyde in the aqueous solution could be realized by measuring the fluorescence intensity of TPE-4OH. By optimizing the conditions of reactant concentration, solution pH value and reaction time, the linear range of detection of formaldehyde was from 1.0 μmol/L to 2000 μmol/L, and the detection limit was 1.0 μmol/L. The results showed that this method had the potential in sensing/diagnosis applications of formaldehyde.
2023, 51(2): 211-218
doi: 10.19756/j.issn.0253-3820.221314
Abstract:
By using ethylenediamine as carbon source and nitrogen source, and 4-hydroxyphenylboronic acid as boron dopant, the boron and nitrogen-doped carbon dots (B,N-CDs) were synthesized in one step using a microwaveassisted method. Its morphology and optical properties were characterized by transmission electron microscopy, ultraviolet-visible absorption spectroscopy, fluorescence spectroscopy, and X-ray photoelectron spectroscopy, respectively. The maximum excitation and emission wavelengths of the carbon dots were 400 nm and 510 nm, respectively. By taking quinine sulfate as a reference, the relative quantum yield of the carbon dots was 9.94%. The presence of Fe3+ could quench the fluorescence of the B,N-CDs, and the fluorescence recovery took place in the presence of ascorbic acid (AA) by reducing Fe3+ to Fe2+. Based on this, a new fluorescence analysis method for detecting AA was established with good selectivity. The fluorescence recovery degree of B,N-CDs showed a good linear relationship with AA concentration in the range of 1.0-80.0 μmol/L, and the detection limit was 0.49 μmol/L (S/N=3). The method was applied to determination of AA in fruit juice with satisfactory results.
By using ethylenediamine as carbon source and nitrogen source, and 4-hydroxyphenylboronic acid as boron dopant, the boron and nitrogen-doped carbon dots (B,N-CDs) were synthesized in one step using a microwaveassisted method. Its morphology and optical properties were characterized by transmission electron microscopy, ultraviolet-visible absorption spectroscopy, fluorescence spectroscopy, and X-ray photoelectron spectroscopy, respectively. The maximum excitation and emission wavelengths of the carbon dots were 400 nm and 510 nm, respectively. By taking quinine sulfate as a reference, the relative quantum yield of the carbon dots was 9.94%. The presence of Fe3+ could quench the fluorescence of the B,N-CDs, and the fluorescence recovery took place in the presence of ascorbic acid (AA) by reducing Fe3+ to Fe2+. Based on this, a new fluorescence analysis method for detecting AA was established with good selectivity. The fluorescence recovery degree of B,N-CDs showed a good linear relationship with AA concentration in the range of 1.0-80.0 μmol/L, and the detection limit was 0.49 μmol/L (S/N=3). The method was applied to determination of AA in fruit juice with satisfactory results.
2023, 51(2): 219-228
doi: 10.19756/j.issn.0253-3820.221469
Abstract:
A novel host-guest inclusion complex MAA/PP6A was constructed by the saturated solution method with water-soluble phosphate salt pillar[6]arene (PP6A) as the host and the natural medicine maackiain (MAA) as the guest. The preparation process of MAA/PP6A clathrate was screened by orthogonal test with the drug loading of clathrate as an index. The inclusion complex MAA/PP6A was characterized by fluorescence spectroscopy, scanning electron microscope (SEM), X-ray powder diffraction (XRD), and infrared spectroscopy (FT-IR). The inclusion mode of MAA and PP6A inclusion complex was studied by nuclear magnetic resonance spectroscopy (NMR), molecular simulation docking and semi-empirical molecular orbital methods. The results of orthogonal experiments showed that the optimal conditions for the preparation of the inclusion complex were as follows: the mass ratio of PP6A to MAA was 2:1, the volume ratio of ethanol to water was 1:1, and reaction at 50 ℃ for 8 h. Fluorescence spectroscopic titration experiment showed that the inclusion ratio between MAA and PP6A was 1:1 and there was a strong interaction between the host and the guest. The host-guest complex constant was calculated to be 2.458×104 L/mol by the non-linear least squares curve fitting method. Analytical test results showed that the inclusion complex was successfully prepared. The water solubility of MAA increased from 0.3463 to 6.123 mg/mL after the formation of the inclusion complex between MAA and PP6A, which effectively improved the water solubility of MAA. Semi-empirical molecular orbital method and molecular docking calculations indicated that there was no hydrogen bond formed between the host and the guest. MAA could enter the cavity of PP6A and formed a conformationally stable inclusion complex. PP6A was a good host for MAA, and the optimal mode was consistent with the NMR results.
A novel host-guest inclusion complex MAA/PP6A was constructed by the saturated solution method with water-soluble phosphate salt pillar[6]arene (PP6A) as the host and the natural medicine maackiain (MAA) as the guest. The preparation process of MAA/PP6A clathrate was screened by orthogonal test with the drug loading of clathrate as an index. The inclusion complex MAA/PP6A was characterized by fluorescence spectroscopy, scanning electron microscope (SEM), X-ray powder diffraction (XRD), and infrared spectroscopy (FT-IR). The inclusion mode of MAA and PP6A inclusion complex was studied by nuclear magnetic resonance spectroscopy (NMR), molecular simulation docking and semi-empirical molecular orbital methods. The results of orthogonal experiments showed that the optimal conditions for the preparation of the inclusion complex were as follows: the mass ratio of PP6A to MAA was 2:1, the volume ratio of ethanol to water was 1:1, and reaction at 50 ℃ for 8 h. Fluorescence spectroscopic titration experiment showed that the inclusion ratio between MAA and PP6A was 1:1 and there was a strong interaction between the host and the guest. The host-guest complex constant was calculated to be 2.458×104 L/mol by the non-linear least squares curve fitting method. Analytical test results showed that the inclusion complex was successfully prepared. The water solubility of MAA increased from 0.3463 to 6.123 mg/mL after the formation of the inclusion complex between MAA and PP6A, which effectively improved the water solubility of MAA. Semi-empirical molecular orbital method and molecular docking calculations indicated that there was no hydrogen bond formed between the host and the guest. MAA could enter the cavity of PP6A and formed a conformationally stable inclusion complex. PP6A was a good host for MAA, and the optimal mode was consistent with the NMR results.
2023, 51(2): 229-238
doi: 10.19756/j.issn.0253-3820.221183
Abstract:
A method for quantification of four kinds of metabolites of di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH) in urine using ultra high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed. Urine sample (2 mL) were deconjugated by β-glucuronidase/arylsulfatase, extracted and cleaned using anion-exchange solid phase extraction cartridge and concentrated to 0.5 mL under gentle stream of nitrogen. The target analytes were separated on Waters Acquity UPLC BEH C18 Column (100 mm×2.1 mm,1.7 μm), and eluted with 0.05% (V/V) acetic acid in water and 0.05% (V/V) acetic acid in acetonitrile in gradient. The target analytes were ionized in negative electrospray ionization (ESI-) mode and scanned under a multiple reaction monitoring (MRM) mode. Quantitative analysis of target analytes in urine was achieved by isotope labelled standard assay. In the range of 0.01-50 ng/mL, all four target analytes exhibited good linearity with correlation coefficients (r) above 0.9996. The method detection limits (MDLs) and method quantification limits (MQLs) were 0.01-0.03 ng/mL and 0.03-0.10 ng/mL, respectively. The recoveies were from 74% to 124%, with the relative standard deviations (RSD) between 1.2% and 15.0%. The intra-day and inter-day precisions were 3.5%-6.2% and 6.9%-9.8%, respectively. The developed method was performed to determinate the DINCH metabolites in 55 human urine samples collected in Beijing. All four DINCH metabolites were detected in urine, and the detected rates of MINCH, oxo-MINCH, OH-MINCH and cx-MINCH were 18.2%, 47.3%, 98.2% and 100%, respectively. The four metabolites were detected in the concentration ranges of
A method for quantification of four kinds of metabolites of di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH) in urine using ultra high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed. Urine sample (2 mL) were deconjugated by β-glucuronidase/arylsulfatase, extracted and cleaned using anion-exchange solid phase extraction cartridge and concentrated to 0.5 mL under gentle stream of nitrogen. The target analytes were separated on Waters Acquity UPLC BEH C18 Column (100 mm×2.1 mm,1.7 μm), and eluted with 0.05% (V/V) acetic acid in water and 0.05% (V/V) acetic acid in acetonitrile in gradient. The target analytes were ionized in negative electrospray ionization (ESI-) mode and scanned under a multiple reaction monitoring (MRM) mode. Quantitative analysis of target analytes in urine was achieved by isotope labelled standard assay. In the range of 0.01-50 ng/mL, all four target analytes exhibited good linearity with correlation coefficients (r) above 0.9996. The method detection limits (MDLs) and method quantification limits (MQLs) were 0.01-0.03 ng/mL and 0.03-0.10 ng/mL, respectively. The recoveies were from 74% to 124%, with the relative standard deviations (RSD) between 1.2% and 15.0%. The intra-day and inter-day precisions were 3.5%-6.2% and 6.9%-9.8%, respectively. The developed method was performed to determinate the DINCH metabolites in 55 human urine samples collected in Beijing. All four DINCH metabolites were detected in urine, and the detected rates of MINCH, oxo-MINCH, OH-MINCH and cx-MINCH were 18.2%, 47.3%, 98.2% and 100%, respectively. The four metabolites were detected in the concentration ranges of
2023, 51(2): 239-249
doi: 10.19756/j.issn.0253-3820.221293
Abstract:
Photothermal agents with strong light absorption in the second near-infrared (NIR-II) region are strongly desired for successful photothermal therapy (PTT). In this work, the lactoferrin-mediated copper sulfide nanoparticles (CuS@Lf NPs) were successfully synthesized by biomineralization strategy. The uniform CuS@Lf NPs showed strong NIR-Ⅱ absorbance in the wavelength range of 1000-1300 nm and possessed high photothermal conversion efficiency, which could be applied in antitumor therapy under 1064 nm laser irradiation. Moreover, lactoferrin (Lf) not only improved the solubility of CuS nanoparticles, but also enhanced their biocompatibility and tumor targeting. Meanwhile, the antioxidant effect of Lf could eliminate oxidative damage after photothermal therapy and reduce tumor recurrence. Herein, the U87 glioma model with high expression of low density lipoprotein receptor associated protein (LRP-1) was used to study the antitumor effects of CuS@Lf NPs in vivo and in vitro. As a result, CuS@Lf NPs displayed effective photothermal tumor ablation, which provided a foundation for NIR-Ⅱ based photothermal therapy in antitumor application.
Photothermal agents with strong light absorption in the second near-infrared (NIR-II) region are strongly desired for successful photothermal therapy (PTT). In this work, the lactoferrin-mediated copper sulfide nanoparticles (CuS@Lf NPs) were successfully synthesized by biomineralization strategy. The uniform CuS@Lf NPs showed strong NIR-Ⅱ absorbance in the wavelength range of 1000-1300 nm and possessed high photothermal conversion efficiency, which could be applied in antitumor therapy under 1064 nm laser irradiation. Moreover, lactoferrin (Lf) not only improved the solubility of CuS nanoparticles, but also enhanced their biocompatibility and tumor targeting. Meanwhile, the antioxidant effect of Lf could eliminate oxidative damage after photothermal therapy and reduce tumor recurrence. Herein, the U87 glioma model with high expression of low density lipoprotein receptor associated protein (LRP-1) was used to study the antitumor effects of CuS@Lf NPs in vivo and in vitro. As a result, CuS@Lf NPs displayed effective photothermal tumor ablation, which provided a foundation for NIR-Ⅱ based photothermal therapy in antitumor application.
2023, 51(2): 250-258
doi: 10.19756/j.issn.0253-3820.221395
Abstract:
The LaCoO3 and LaCoO3/CeO2 nanomaterials were synthesized by sol-gel method, and the heterojunction formaldehyde gas sensor was designed by depositing the samples onto the alumina ceramic tube with Au electrodes by dip-coating method. The crystalline phase and microstructure of the samples were displayed using X-ray diffraction (XRD) and scanning electron microscope (SEM), and the electrochemical characteristic of the samples were analyzed by X-ray photoelectron spectroscopy (XPS). Density functional theory (DFT) was used to calculate the work function, total density of states and energy band of LaCoO3/CeO2 heterojunction, and the sensitization mechanism of sensor was further proposed for detecting formaldehyde in detail from the adsorption process of surface oxygen, heterojunction action and LaCoO3 catalytic oxidation process. Characteristic tests of formaldehyde gas sensor were carried out by WS-30A type multifunction analyzer in gas sensor test system. At the optimal operating temperature of 150 ℃, the maximum response of LaCoO3/CeO2 sensor to 20 μg/m3 formaldehyde gas reached 60.1. Meanwhile, the response time and recovery time of LaCoO3/CeO2 sensor were reduced to 5.6 and 9.8 s, respectively. The detection limit was 1.0 μg/m3 (S/N = 6). All the results demonstrated that LaCoO3 was an excellent catalyst for improving the gas-sensitive performance of metal oxide semiconductor sensors.
The LaCoO3 and LaCoO3/CeO2 nanomaterials were synthesized by sol-gel method, and the heterojunction formaldehyde gas sensor was designed by depositing the samples onto the alumina ceramic tube with Au electrodes by dip-coating method. The crystalline phase and microstructure of the samples were displayed using X-ray diffraction (XRD) and scanning electron microscope (SEM), and the electrochemical characteristic of the samples were analyzed by X-ray photoelectron spectroscopy (XPS). Density functional theory (DFT) was used to calculate the work function, total density of states and energy band of LaCoO3/CeO2 heterojunction, and the sensitization mechanism of sensor was further proposed for detecting formaldehyde in detail from the adsorption process of surface oxygen, heterojunction action and LaCoO3 catalytic oxidation process. Characteristic tests of formaldehyde gas sensor were carried out by WS-30A type multifunction analyzer in gas sensor test system. At the optimal operating temperature of 150 ℃, the maximum response of LaCoO3/CeO2 sensor to 20 μg/m3 formaldehyde gas reached 60.1. Meanwhile, the response time and recovery time of LaCoO3/CeO2 sensor were reduced to 5.6 and 9.8 s, respectively. The detection limit was 1.0 μg/m3 (S/N = 6). All the results demonstrated that LaCoO3 was an excellent catalyst for improving the gas-sensitive performance of metal oxide semiconductor sensors.
2023, 51(2): 259-268
doi: 10.19756/j.issn.0253-3820.221361
Abstract:
The cochineal hyperbranched polyglycidyl ether magnetic adsorbents (Fe3O4-HPG) were synthesized for adsorption of cochineal with glycidyl ether as functional monomer, cochineal as target, and Fe3O4 as carrier by a simple and ingenious synthesis method for the first time. The physical and chemical properties of the materials were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). These results showed that Fe3O4-HPG had uniform particle size, good magnetism, and stable crystal structure. At the same time, the kinetic adsorption, thermodynamic adsorption, and reusability of Fe3O4-HPG were investigated. The prepared materials had high adsorption capacity (106.06 mg/g), fast adsorption rate (60 min) and good reusability (Adsorption efficiency of 95.8% after reusing for 8 times). Moreover, combined with high performance liquid chromatography, the Fe3O4-HPG as adsorbents were successfully used to specifically recognize and detect cochineal in environmental water with recoveries over 94.6%.
The cochineal hyperbranched polyglycidyl ether magnetic adsorbents (Fe3O4-HPG) were synthesized for adsorption of cochineal with glycidyl ether as functional monomer, cochineal as target, and Fe3O4 as carrier by a simple and ingenious synthesis method for the first time. The physical and chemical properties of the materials were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). These results showed that Fe3O4-HPG had uniform particle size, good magnetism, and stable crystal structure. At the same time, the kinetic adsorption, thermodynamic adsorption, and reusability of Fe3O4-HPG were investigated. The prepared materials had high adsorption capacity (106.06 mg/g), fast adsorption rate (60 min) and good reusability (Adsorption efficiency of 95.8% after reusing for 8 times). Moreover, combined with high performance liquid chromatography, the Fe3O4-HPG as adsorbents were successfully used to specifically recognize and detect cochineal in environmental water with recoveries over 94.6%.
2023, 51(2): 269-275
doi: 10.19756/j.issn.0253-3820.221315
Abstract:
In this work, a quadrupole-dual pressure linear ion trap (Q-DPLIT) tandem mass spectrometer was developed and combined with a simultaneous technique to further improve the sensitivity and accuracy. The instrument consisted of a quadrupole and two hyperbolic ion traps in axial series. The precursor ions were filtered by the quadrupole into the linear ion trap Ⅰ (LITⅠ). At the same time, a composite waveform was applied to the LITI, so that the fragmentation of the precursor ions, isolation and accumulation of product ions occurred simultaneously. Then, the product ions were transferred to the linear ion trap Ⅱ (LITⅡ) for detection. By changing the helium flux introduced into LITⅠ, the ion trapping ability of the ion trap under different fluxes was investigated, and the optimal analysis condition was obtained. The results showed that the number of reserpine ions trapped by Q-DPLIT was 4.2 times as that of Q-LIT under the respective optimal conditions. The target peptide GVFGVF in concentrations ranging from 10 to 100 ng/mL with 100 μg/mL VVFFGG as the matrix was detected by Q-DPLIT. The mass-to-charge ratios (m/z) of VVFFGG and GVFGVF were both 625.3 amu. The ion accumulation time was 0.1-10 s. The signal intensity of the target product ion (m/z = 460.3 amu) measured by the simultaneous technique was improved by 1.3-10 times compared with that without this technique, and the linear correlation coefficient was increased from 0.6693-0.9449 to 0.9942-0.9994. The combination of Q-DPLIT and simultaneous technique could further improve the sensitivity and reduced the interferences of matrices. It was expected to achieve better analytical results in the analysis of trace substances in complex matrices in the future.
In this work, a quadrupole-dual pressure linear ion trap (Q-DPLIT) tandem mass spectrometer was developed and combined with a simultaneous technique to further improve the sensitivity and accuracy. The instrument consisted of a quadrupole and two hyperbolic ion traps in axial series. The precursor ions were filtered by the quadrupole into the linear ion trap Ⅰ (LITⅠ). At the same time, a composite waveform was applied to the LITI, so that the fragmentation of the precursor ions, isolation and accumulation of product ions occurred simultaneously. Then, the product ions were transferred to the linear ion trap Ⅱ (LITⅡ) for detection. By changing the helium flux introduced into LITⅠ, the ion trapping ability of the ion trap under different fluxes was investigated, and the optimal analysis condition was obtained. The results showed that the number of reserpine ions trapped by Q-DPLIT was 4.2 times as that of Q-LIT under the respective optimal conditions. The target peptide GVFGVF in concentrations ranging from 10 to 100 ng/mL with 100 μg/mL VVFFGG as the matrix was detected by Q-DPLIT. The mass-to-charge ratios (m/z) of VVFFGG and GVFGVF were both 625.3 amu. The ion accumulation time was 0.1-10 s. The signal intensity of the target product ion (m/z = 460.3 amu) measured by the simultaneous technique was improved by 1.3-10 times compared with that without this technique, and the linear correlation coefficient was increased from 0.6693-0.9449 to 0.9942-0.9994. The combination of Q-DPLIT and simultaneous technique could further improve the sensitivity and reduced the interferences of matrices. It was expected to achieve better analytical results in the analysis of trace substances in complex matrices in the future.
2023, 51(2): 276-286
doi: 10.19756/j.issn.0253-3820.221494
Abstract:
Homogeneous and split-type photoelectrochemical (PEC) sensors based on the enhancement effect of Cd2+ on the photocurrent of lead selenide quantum dots (PbSe QDs) were constructed for sensitive detection of miRNA-21 and carcinoembryonic antigen (CEA). The detection method used the hairpin DNA assembly by T-Hg2+-T base mismatch, whose loops were combined with miRNA-21 or the complementary strand of CEA aptamer to form double strands. Signal amplification was carried out by non-enzymatic DNA strand displacement reaction to release Hg2+ in the hairpin structure, and then the released Hg2+ exchanged ions with cadmium sulfide quantum dots (CdS QDs) to release Cd2+. Then, Cd2+ reacted with PbSe QDs modified electrode to form cadmium selenide (CdSe) layer on its surface, which eliminated the electron-hole recombination center on the surface and improved the charge separation efficiency, realizing enhanced photocurrent output. The experimental results showed that the linear range for detection of miRNA-21 was 5.0×10-16-5.0×10-10 mol/L, and the detection limit was 6.8×10-17 mol/L (S/N = 3). The logarithm of the concentration of CEA was linear with the photocurrent in the range of 5.0×10-2-5.0×104 pg/mL, and the detection limit was 0.007 pg/mL (S/N = 3). The developed PEC biosensors showed good selectivity and could be used for detection of real samples with satisfactory results.
Homogeneous and split-type photoelectrochemical (PEC) sensors based on the enhancement effect of Cd2+ on the photocurrent of lead selenide quantum dots (PbSe QDs) were constructed for sensitive detection of miRNA-21 and carcinoembryonic antigen (CEA). The detection method used the hairpin DNA assembly by T-Hg2+-T base mismatch, whose loops were combined with miRNA-21 or the complementary strand of CEA aptamer to form double strands. Signal amplification was carried out by non-enzymatic DNA strand displacement reaction to release Hg2+ in the hairpin structure, and then the released Hg2+ exchanged ions with cadmium sulfide quantum dots (CdS QDs) to release Cd2+. Then, Cd2+ reacted with PbSe QDs modified electrode to form cadmium selenide (CdSe) layer on its surface, which eliminated the electron-hole recombination center on the surface and improved the charge separation efficiency, realizing enhanced photocurrent output. The experimental results showed that the linear range for detection of miRNA-21 was 5.0×10-16-5.0×10-10 mol/L, and the detection limit was 6.8×10-17 mol/L (S/N = 3). The logarithm of the concentration of CEA was linear with the photocurrent in the range of 5.0×10-2-5.0×104 pg/mL, and the detection limit was 0.007 pg/mL (S/N = 3). The developed PEC biosensors showed good selectivity and could be used for detection of real samples with satisfactory results.
2023, 51(2): 287-295
doi: 10.19756/j.issn.0253-3820.221313
Abstract:
Peroxy radicals (RO2* = RO2 + HO2) are key intermediates in the atmospheric oxidation of volatile organic compounds, and play a key role in the degradation of primary atmospheric pollution and the formation of secondary pollutants. It is of great significance to accurately measure the concentration of RO2* for understanding the atmospheric chemical reaction mechanism and the cause of atmospheric pollution. In this work, a broadband cavity enhanced absorption spectroscopy-chemically amplified peroxy radical instrument was used to measure the peroxy radical in-situ. Combined with the measurement of NO, the photochemical ozone production rate could be determined in real time. Observations were made in Huaibei city during summer 2021, to characterize ozone production. The results showed that the average peaking peroxy radical concentration was 75×10-12(V/V), while the average ozone peaking production rate was 14×10-12(V/V) in summer in Huaibei. The ozone production rate was more sensitive to the NO concentration changes. In addition, during the pollution period, the photochemical generation of ozone increased significantly, which made an important contribution to the local high concentration of O3.
Peroxy radicals (RO2* = RO2 + HO2) are key intermediates in the atmospheric oxidation of volatile organic compounds, and play a key role in the degradation of primary atmospheric pollution and the formation of secondary pollutants. It is of great significance to accurately measure the concentration of RO2* for understanding the atmospheric chemical reaction mechanism and the cause of atmospheric pollution. In this work, a broadband cavity enhanced absorption spectroscopy-chemically amplified peroxy radical instrument was used to measure the peroxy radical in-situ. Combined with the measurement of NO, the photochemical ozone production rate could be determined in real time. Observations were made in Huaibei city during summer 2021, to characterize ozone production. The results showed that the average peaking peroxy radical concentration was 75×10-12(V/V), while the average ozone peaking production rate was 14×10-12(V/V) in summer in Huaibei. The ozone production rate was more sensitive to the NO concentration changes. In addition, during the pollution period, the photochemical generation of ozone increased significantly, which made an important contribution to the local high concentration of O3.
2023, 51(2): 296-304
doi: 10.19756/j.issn.0253-3820.221407
Abstract:
Nitrogen and phosphorus codoped carbon nanoparticles (N/P-CNPs) were synthesized by one-step hydrothermal method using ammonium phosphate and sodium ascorbate as raw materials, with a quantum yield of 19%. Based on the rapid and highly selective quenching of N/P-CNPs by calcium folinate (CF), a new method for quantitative determination of CF in CF injection samples was established. Under the optimal experimental conditions, the concentration of CF in the range of 0.2-108.5 μmol/L and the degree of fluorescence quenching of N/P-CNPs ((F0-F)/F0, F0 is the initial fluorescence intensity, F is the fluorescence intensity after adding CF) showed a good linear relationship. The detection limit was 0.05 μmol/L. Besides, it was verified that the fluorescence quenching mechanism of CF on N/P-CNPs was inner filter effect and static quenching effect. The established method was used to detect the content of CF in actual samples, and the obtained results were basically consistent with the results of high performance liquid chromatography, indicating that the method had good practicability and provided a new strategy for the detection of CF.
Nitrogen and phosphorus codoped carbon nanoparticles (N/P-CNPs) were synthesized by one-step hydrothermal method using ammonium phosphate and sodium ascorbate as raw materials, with a quantum yield of 19%. Based on the rapid and highly selective quenching of N/P-CNPs by calcium folinate (CF), a new method for quantitative determination of CF in CF injection samples was established. Under the optimal experimental conditions, the concentration of CF in the range of 0.2-108.5 μmol/L and the degree of fluorescence quenching of N/P-CNPs ((F0-F)/F0, F0 is the initial fluorescence intensity, F is the fluorescence intensity after adding CF) showed a good linear relationship. The detection limit was 0.05 μmol/L. Besides, it was verified that the fluorescence quenching mechanism of CF on N/P-CNPs was inner filter effect and static quenching effect. The established method was used to detect the content of CF in actual samples, and the obtained results were basically consistent with the results of high performance liquid chromatography, indicating that the method had good practicability and provided a new strategy for the detection of CF.
