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2018 Volume 29 Issue 10
2018, 29(10): 1425-1428
doi: 10.1016/j.cclet.2018.08.009
Abstract:
Fluorescent NIR-Ⅱ imaging has a wide range of benefits not offered by other imaging modalities for biomedical applications, derived from its combination of high spatial and temporal resolution due to reduced photon absorption, scattering and tissue auto-fluorescence. Compared to the well-studied NIR-Ⅰ small-molecule fluorophores, the structures of NIR-Ⅱ fluorophores are scarce. To date, the main fluorophore units are composed of conjugated π system with a benzobisthiadiazole (BBTD) core and donor-acceptor-donor (D-A-D) structure. Herein, researchers Yang et al. and Zhang et al. have reported new NIR-Ⅱ probes ECX and FD-1080 respectively without a BBTD core which are highlighted.
Fluorescent NIR-Ⅱ imaging has a wide range of benefits not offered by other imaging modalities for biomedical applications, derived from its combination of high spatial and temporal resolution due to reduced photon absorption, scattering and tissue auto-fluorescence. Compared to the well-studied NIR-Ⅰ small-molecule fluorophores, the structures of NIR-Ⅱ fluorophores are scarce. To date, the main fluorophore units are composed of conjugated π system with a benzobisthiadiazole (BBTD) core and donor-acceptor-donor (D-A-D) structure. Herein, researchers Yang et al. and Zhang et al. have reported new NIR-Ⅱ probes ECX and FD-1080 respectively without a BBTD core which are highlighted.
2018, 29(10): 1429-1435
doi: 10.1016/j.cclet.2018.08.011
Abstract:
Organic chromic materials that respond to external stimuli, especially in the solid state, have sparked extensive interest owing to their potential use as smart materials. In particular, the availability of chromic materials, which emit fluorescence or phosphorescence in the deep penetrating, near-infrared (NIR) region, has led to great improvements in imaging. Various methods that were commonly applied to construct chromic materials, have been reformed to develop the novel type of compounds, and some have received rewards with excellent fingdings. Relevant research achievements of practical applications have showed their potential with the changes that locate in the NIR region, while further in-depth explorations about the inherent chromic chromism are underway. In this review, several representative studies, which have led the development of responsive organic chromic materials with near-infrared emission, will be discussed.
Organic chromic materials that respond to external stimuli, especially in the solid state, have sparked extensive interest owing to their potential use as smart materials. In particular, the availability of chromic materials, which emit fluorescence or phosphorescence in the deep penetrating, near-infrared (NIR) region, has led to great improvements in imaging. Various methods that were commonly applied to construct chromic materials, have been reformed to develop the novel type of compounds, and some have received rewards with excellent fingdings. Relevant research achievements of practical applications have showed their potential with the changes that locate in the NIR region, while further in-depth explorations about the inherent chromic chromism are underway. In this review, several representative studies, which have led the development of responsive organic chromic materials with near-infrared emission, will be discussed.
2018, 29(10): 1436-1444
doi: 10.1016/j.cclet.2017.12.020
Abstract:
Fluorescent metal nanoclusters (MNCs) have recently emerged as a novel kind of promising fluorescent probes for biological imaging because of their ultrasmall core size (< 2 nm), strong photoluminescence, facile availability and good biocompatibility. In this review, we provide an update on recent advances in the development of near infrared (NIR)-emitting MNCs in terms of synthesis strategies and bioimaging applications. We mainly focus on the utilization of NIR-emitting MNCs (including Au, Ag, Cu and alloy NCs) either as single modal imaging (fluorescence intensity-based imaging, fluorescence lifetime imaging, two-photon imaging) probes or as multimodal imaging (such as NIR fluorescence/X-ray computed tomography/magnetic resonance imaging, NIR fluorescence/photoacoustic imaging/magnetic resonance imaging, NIR fluorescence/single photon emission computed tomography) probes in biological cells and tissues. Finally, we give a brief outlook on the future challenges and prospects of developing NIR-emitting MNCs for bioimaging.
Fluorescent metal nanoclusters (MNCs) have recently emerged as a novel kind of promising fluorescent probes for biological imaging because of their ultrasmall core size (< 2 nm), strong photoluminescence, facile availability and good biocompatibility. In this review, we provide an update on recent advances in the development of near infrared (NIR)-emitting MNCs in terms of synthesis strategies and bioimaging applications. We mainly focus on the utilization of NIR-emitting MNCs (including Au, Ag, Cu and alloy NCs) either as single modal imaging (fluorescence intensity-based imaging, fluorescence lifetime imaging, two-photon imaging) probes or as multimodal imaging (such as NIR fluorescence/X-ray computed tomography/magnetic resonance imaging, NIR fluorescence/photoacoustic imaging/magnetic resonance imaging, NIR fluorescence/single photon emission computed tomography) probes in biological cells and tissues. Finally, we give a brief outlook on the future challenges and prospects of developing NIR-emitting MNCs for bioimaging.
2018, 29(10): 1445-1450
doi: 10.1016/j.cclet.2018.09.002
Abstract:
During the last few years, the preparation of novel fluorescent probes for the detection of carbon dioxide has attracted considerable attention since carbon dioxide plays extremely important roles in widespread fields including chemical, environmental, clinical analysis, and agri-food industry. This review focuses on the recent advances in the design principles, recognition mechanisms, and preparation of small-molecule fluorescent probes for the selective detection and monitoring of CO2. Moreover, their properties and functions will be discussed detailedly as well.
During the last few years, the preparation of novel fluorescent probes for the detection of carbon dioxide has attracted considerable attention since carbon dioxide plays extremely important roles in widespread fields including chemical, environmental, clinical analysis, and agri-food industry. This review focuses on the recent advances in the design principles, recognition mechanisms, and preparation of small-molecule fluorescent probes for the selective detection and monitoring of CO2. Moreover, their properties and functions will be discussed detailedly as well.
2018, 29(10): 1451-1455
doi: 10.1016/j.cclet.2018.04.007
Abstract:
Nitroreductase (NTR) is a member of flavin-containing enzymes that exists widely in bacteria. Hypoxia, which is a characteristic of locally advanced solid tumors, resulting from an imbalance between oxygen consumption and supply, can result in NTR overexpression. Using either nicotinamide adenine dinucleotide (NADH) or nicotinamide adenine dinucleotide phosphate (NADPH) as a source of reducing equivalents, NTR can catalyze the reduction of nitroaromatic compounds to the corresponding amines. Based on this reduction mechanism, NTR can be applied not only in the bioremediation and degradation of organic nitrogen compounds, but also in the development of NTR-targeted fluorescent probes to detect the hypoxic status of cancer cells. This review aims to provide a summary of the progress in fluorescent probes for NTR in recent years and elucidate the main fluorescent mechanisms that have been applied to design probes.
Nitroreductase (NTR) is a member of flavin-containing enzymes that exists widely in bacteria. Hypoxia, which is a characteristic of locally advanced solid tumors, resulting from an imbalance between oxygen consumption and supply, can result in NTR overexpression. Using either nicotinamide adenine dinucleotide (NADH) or nicotinamide adenine dinucleotide phosphate (NADPH) as a source of reducing equivalents, NTR can catalyze the reduction of nitroaromatic compounds to the corresponding amines. Based on this reduction mechanism, NTR can be applied not only in the bioremediation and degradation of organic nitrogen compounds, but also in the development of NTR-targeted fluorescent probes to detect the hypoxic status of cancer cells. This review aims to provide a summary of the progress in fluorescent probes for NTR in recent years and elucidate the main fluorescent mechanisms that have been applied to design probes.
2018, 29(10): 1456-1464
doi: 10.1016/j.cclet.2018.08.012
Abstract:
Sulfur dioxide (SO2) is a harmful environmental pollutant. Inhaled SO2 can be rapidly hydrated into its derivatives, bisulfite (HSO3-) and sulfite (SO32-). SO2 derivatives are well known as preservatives and antioxidants, which are used in food and beverages to prevent oxidation and bacterial growth. Although SO2 can be endogenously generated in mammals and exhibits unique bioactivities in regulating cardiovascular function, excessive SO2 and its derivatives have toxic effects on humans and animals for triggering adverse reactions and diseases. A large number of fluorescent probes for SO2 and its derivatives have been designed and reported due to their high sensitivity and selectivity, high temporal and spatial resolution, non-invasive and non-destructive detection as well as real-time visualization in situ. In this review, we have summarized the recent progress of Michael addition-based fluorescent probes for SO2 and its derivatives. These probes are categorized and concluded according to the different α, β-unsaturated compounds (i.e., Michael acceptors). The design strategies, sensing performances, detection mechanisms and applications of these probes are discussed in detailed. Finally, a general overview about the design of probes for SO2 and its derivatives is provided, which will facilitate the development of ideal probes for SO2 and its derivatives.
Sulfur dioxide (SO2) is a harmful environmental pollutant. Inhaled SO2 can be rapidly hydrated into its derivatives, bisulfite (HSO3-) and sulfite (SO32-). SO2 derivatives are well known as preservatives and antioxidants, which are used in food and beverages to prevent oxidation and bacterial growth. Although SO2 can be endogenously generated in mammals and exhibits unique bioactivities in regulating cardiovascular function, excessive SO2 and its derivatives have toxic effects on humans and animals for triggering adverse reactions and diseases. A large number of fluorescent probes for SO2 and its derivatives have been designed and reported due to their high sensitivity and selectivity, high temporal and spatial resolution, non-invasive and non-destructive detection as well as real-time visualization in situ. In this review, we have summarized the recent progress of Michael addition-based fluorescent probes for SO2 and its derivatives. These probes are categorized and concluded according to the different α, β-unsaturated compounds (i.e., Michael acceptors). The design strategies, sensing performances, detection mechanisms and applications of these probes are discussed in detailed. Finally, a general overview about the design of probes for SO2 and its derivatives is provided, which will facilitate the development of ideal probes for SO2 and its derivatives.
2018, 29(10): 1465-1474
doi: 10.1016/j.cclet.2018.09.001
Abstract:
The Cu(Ⅰ)-catalyzed azide-alkyne 1, 3-dipolar cycloaddition (CuAAC) reaction, popularly known as the "click reaction", have been widely used in chemosensor field. This reaction gives a mild and efficient coupling reaction between the binding site and the reporter. In addition, the formation 1, 4-disubstituted 1, 2, 3-triazole linker shows a high binding affinity toward both anions and metal ions. Recently researches revealed this reaction is also an efficient tool to form rigid or shape-persistent, preorganized macrocyclic species. This review summarized the recent advances in click derived macrocyclic receptors for recognition of anion, metal ion and ions pair.
The Cu(Ⅰ)-catalyzed azide-alkyne 1, 3-dipolar cycloaddition (CuAAC) reaction, popularly known as the "click reaction", have been widely used in chemosensor field. This reaction gives a mild and efficient coupling reaction between the binding site and the reporter. In addition, the formation 1, 4-disubstituted 1, 2, 3-triazole linker shows a high binding affinity toward both anions and metal ions. Recently researches revealed this reaction is also an efficient tool to form rigid or shape-persistent, preorganized macrocyclic species. This review summarized the recent advances in click derived macrocyclic receptors for recognition of anion, metal ion and ions pair.
2018, 29(10): 1475-1485
doi: 10.1016/j.cclet.2018.07.004
Abstract:
Quantum dots (QDs), with several unique optical and chemical features, are becoming desirable fluorescent tags for the biological applications that require long-term and highly sensitive imaging. Besides, the conjugation of various functional biomolecules to QDs has enabled wide applications of QDs in biological imaging. This review focuses on the following four types of QDs:semiconductor quantum dots (semiconductor QDs), carbon nanodots (CDs), silicon quantum dots (SiQDs), and polymer dots (Pdots), and summarizes the recent advancements of using these QDs in imaging microorganisms including viruses, bacteria, and fungi. We hope that this review will promote the development of new fluorescent QDs for microbial imaging and extend the applications of QD-based imaging techniques in cell biology and beyond.
Quantum dots (QDs), with several unique optical and chemical features, are becoming desirable fluorescent tags for the biological applications that require long-term and highly sensitive imaging. Besides, the conjugation of various functional biomolecules to QDs has enabled wide applications of QDs in biological imaging. This review focuses on the following four types of QDs:semiconductor quantum dots (semiconductor QDs), carbon nanodots (CDs), silicon quantum dots (SiQDs), and polymer dots (Pdots), and summarizes the recent advancements of using these QDs in imaging microorganisms including viruses, bacteria, and fungi. We hope that this review will promote the development of new fluorescent QDs for microbial imaging and extend the applications of QD-based imaging techniques in cell biology and beyond.
2018, 29(10): 1486-1488
doi: 10.1016/j.cclet.2018.08.008
Abstract:
In this letter, excited state dynamics of TPZ2, a centrosymmetric PRODAN dye, has been studied by using several time-resolved spectroscopy techniques. Fluorescence quantum yield of TPZ2 is found to be 0.50 in both acetonitrile and ethanol solution. The radiative decay rate of the excited state of TPZ2 is determined to be 2.0×108 s-1. Meanwhile, highly efficient triplet state and singlet oxygen generation have been observed in TPZ2 and the intersystem crossing (ISC) rate is determined to be 2.0×108 s-1. The almost identical ISC and non-radiative decay rates indicate that ISC is the only non-radiative decay pathway in TPZ2. Thus, dual excited state (S1) deactivation mechanism (50/50, fluorescence/ISC) of TPZ2 is proposed. Because of this unique property, TPZ2 has the potential to be used as biocompatible imaging and photodynamic therapy agent in the same time.
In this letter, excited state dynamics of TPZ2, a centrosymmetric PRODAN dye, has been studied by using several time-resolved spectroscopy techniques. Fluorescence quantum yield of TPZ2 is found to be 0.50 in both acetonitrile and ethanol solution. The radiative decay rate of the excited state of TPZ2 is determined to be 2.0×108 s-1. Meanwhile, highly efficient triplet state and singlet oxygen generation have been observed in TPZ2 and the intersystem crossing (ISC) rate is determined to be 2.0×108 s-1. The almost identical ISC and non-radiative decay rates indicate that ISC is the only non-radiative decay pathway in TPZ2. Thus, dual excited state (S1) deactivation mechanism (50/50, fluorescence/ISC) of TPZ2 is proposed. Because of this unique property, TPZ2 has the potential to be used as biocompatible imaging and photodynamic therapy agent in the same time.
2018, 29(10): 1489-1492
doi: 10.1016/j.cclet.2018.06.022
Abstract:
Two functional tetraphenylethylene derivatives modified by vinylpyridine and vinylnitrobenzene, respectively, were synthesized by Heck coupling reaction. Their optical behaviors were investigated. The results showed they had AIE activity in solution. The property in solid state displayed that both of them had reversible mechanochromism. Upon grinding, their fluorescence spectra showed around 13-40 nm red-shift, and could return to the original state after solvent fuming. We believe that this work will be helpful for the design of stimuli-responsive materials in future.
Two functional tetraphenylethylene derivatives modified by vinylpyridine and vinylnitrobenzene, respectively, were synthesized by Heck coupling reaction. Their optical behaviors were investigated. The results showed they had AIE activity in solution. The property in solid state displayed that both of them had reversible mechanochromism. Upon grinding, their fluorescence spectra showed around 13-40 nm red-shift, and could return to the original state after solvent fuming. We believe that this work will be helpful for the design of stimuli-responsive materials in future.
2018, 29(10): 1493-1496
doi: 10.1016/j.cclet.2018.05.043
Abstract:
Three salicylaldehyde Schiff base (SSB), iso-PBP, PBP and EPB, were facilely synthesized and exhibited aggregation-induced emission. The introduction of C=N-N=C moiety in these SSB dyes largely extend the conjugation system and push their emission to yellow to red spectral region. These SSB dyes were negligibly fluorescent in dilute THF solution. In THF/water mixtures with high water fractions, they displayed strong yellow to red fluorescence (up to 617 nm) and large Stokes shifts (up to 152 nm). Single crystal analysis on EBP showed the longer emission of in aggregated state was attributed to the molecular packing effect as compared with that in dilute solution. The bio-imaging application indicated EBP could specifically accumulate in lipid droplets in living cells.
Three salicylaldehyde Schiff base (SSB), iso-PBP, PBP and EPB, were facilely synthesized and exhibited aggregation-induced emission. The introduction of C=N-N=C moiety in these SSB dyes largely extend the conjugation system and push their emission to yellow to red spectral region. These SSB dyes were negligibly fluorescent in dilute THF solution. In THF/water mixtures with high water fractions, they displayed strong yellow to red fluorescence (up to 617 nm) and large Stokes shifts (up to 152 nm). Single crystal analysis on EBP showed the longer emission of in aggregated state was attributed to the molecular packing effect as compared with that in dilute solution. The bio-imaging application indicated EBP could specifically accumulate in lipid droplets in living cells.
2018, 29(10): 1497-1499
doi: 10.1016/j.cclet.2018.08.019
Abstract:
Nitric oxide (NO) donors are versatile tools for nitric oxide biology. The biological response of NO is dependent on the transient concentration and the sustained duration. N-Nitrosated rhodamines are photo-triggered and photo-calibrated NO donors. We recently discovered that suppression of the dihedral angle between the N-nitroso fragment with the rhodamine scaffold facilitates NO release. Inspired by this discovery, we developed a fast-releasing NO donor (NOD575) suitable for biological applications, e.g., the pulmonary arterial smooth muscle cells (PASMCs).
Nitric oxide (NO) donors are versatile tools for nitric oxide biology. The biological response of NO is dependent on the transient concentration and the sustained duration. N-Nitrosated rhodamines are photo-triggered and photo-calibrated NO donors. We recently discovered that suppression of the dihedral angle between the N-nitroso fragment with the rhodamine scaffold facilitates NO release. Inspired by this discovery, we developed a fast-releasing NO donor (NOD575) suitable for biological applications, e.g., the pulmonary arterial smooth muscle cells (PASMCs).
2018, 29(10): 1500-1502
doi: 10.1016/j.cclet.2018.07.018
Abstract:
Two kinds of fluorescent nano-probes (pH-A and pH-B) with different diameters for the determination of H+ concentration, based on photo-induced electron transfer mechanism, were synthesized through click reaction. In which 1, 8-naphthalimide was employed as the fluorophore and N, N-dimethylethylenediamine as the receptor. The effects of particle size and linker length on the photophysical properties of the probe were studied. The results revealed that the nano-probes were more sensitive toward pH with increasing particle size. The fluorescence intensity at 529 nm (I529) of the nano-probe pH-A of 120 nm exhibited good linear relationship with solution's pH in the range of 6-8. The probe pH-A displayed excellent selectivity and competition toward proton over other possible coexisted ions, and it could be applied to detect pH in realistic samples (river water, urine).
Two kinds of fluorescent nano-probes (pH-A and pH-B) with different diameters for the determination of H+ concentration, based on photo-induced electron transfer mechanism, were synthesized through click reaction. In which 1, 8-naphthalimide was employed as the fluorophore and N, N-dimethylethylenediamine as the receptor. The effects of particle size and linker length on the photophysical properties of the probe were studied. The results revealed that the nano-probes were more sensitive toward pH with increasing particle size. The fluorescence intensity at 529 nm (I529) of the nano-probe pH-A of 120 nm exhibited good linear relationship with solution's pH in the range of 6-8. The probe pH-A displayed excellent selectivity and competition toward proton over other possible coexisted ions, and it could be applied to detect pH in realistic samples (river water, urine).
2018, 29(10): 1503-1508
doi: 10.1016/j.cclet.2017.12.006
Abstract:
Elongation factor 4 (EF4) is one of the highly conserved translational GTPases, whose functions are largely unknown. Structures of EF4 bound ribosomal PRE-translocation and POST-translocation complexes have both been visualized. On top of cellular, structural, and biochemical studies, several controversial models have been raised to rationalize functions of EF4. However, how EF4 modulates elongation through its interactions with ribosomes has not been revealed. Here, using single-molecule fluorescence resonance energy transfer assays, we directly captured short-lived EF4·GTP bound ribosomal PRE and POST translocation complexes, which may adopt slightly different conformations from structures prepared using GDP, GDPNP, or GDPCP. Furthermore, we revealed that EF4·GTP severely impairs delivery of aminoacyl-tRNA into the A-site of the ribosome and moderately accelerates translocation. We proposed that functions of EF4 are to slow overall elongation and to stall majority of ribosomes in POSTstates under stress conditions.
Elongation factor 4 (EF4) is one of the highly conserved translational GTPases, whose functions are largely unknown. Structures of EF4 bound ribosomal PRE-translocation and POST-translocation complexes have both been visualized. On top of cellular, structural, and biochemical studies, several controversial models have been raised to rationalize functions of EF4. However, how EF4 modulates elongation through its interactions with ribosomes has not been revealed. Here, using single-molecule fluorescence resonance energy transfer assays, we directly captured short-lived EF4·GTP bound ribosomal PRE and POST translocation complexes, which may adopt slightly different conformations from structures prepared using GDP, GDPNP, or GDPCP. Furthermore, we revealed that EF4·GTP severely impairs delivery of aminoacyl-tRNA into the A-site of the ribosome and moderately accelerates translocation. We proposed that functions of EF4 are to slow overall elongation and to stall majority of ribosomes in POSTstates under stress conditions.
2018, 29(10): 1509-1512
doi: 10.1016/j.cclet.2018.04.026
Abstract:
Fluorescence microscopy, as a sensitive method to detect microenvironment of molecules, is widely used in protein conformation and dynamic studies in live cells. Fluorescence lifetime imaging microscopy (FLIM), which is independent of fluorophore concentrations, scattering and bleaching, is a suitable tool to analyze membrane proteins in a single cell. Ferroportin (FPN), a multi-ion exporter in vertebrates, was modulated by metal ions with unknown mechanism. Herein, we fused green fluorescence protein on Cterminal of FPN (FPN-eGFP) and applied fluorescence lifetime to monitor conformation changes of FPN in a live cell. The fluorescence lifetime distribution showed a shift to shorter lifetime upon Mn2+ treatment, suggesting a preference conformation of FPN in Mn2+ exposure. It is also observed that the lifetime (rather than intensity) measurement was not strongly influenced by laser power. The observed fluorescence lifetime changes of FPN-eGFP upon Mn2+ treatments indicated that extracellular metal ions can modulate FPN through conformation exchanges between several different states.
Fluorescence microscopy, as a sensitive method to detect microenvironment of molecules, is widely used in protein conformation and dynamic studies in live cells. Fluorescence lifetime imaging microscopy (FLIM), which is independent of fluorophore concentrations, scattering and bleaching, is a suitable tool to analyze membrane proteins in a single cell. Ferroportin (FPN), a multi-ion exporter in vertebrates, was modulated by metal ions with unknown mechanism. Herein, we fused green fluorescence protein on Cterminal of FPN (FPN-eGFP) and applied fluorescence lifetime to monitor conformation changes of FPN in a live cell. The fluorescence lifetime distribution showed a shift to shorter lifetime upon Mn2+ treatment, suggesting a preference conformation of FPN in Mn2+ exposure. It is also observed that the lifetime (rather than intensity) measurement was not strongly influenced by laser power. The observed fluorescence lifetime changes of FPN-eGFP upon Mn2+ treatments indicated that extracellular metal ions can modulate FPN through conformation exchanges between several different states.
2018, 29(10): 1513-1516
doi: 10.1016/j.cclet.2018.08.002
Abstract:
Fluorescence lifetime and anisotropy has become a prevalent tool to detect the structure change and motility property of proteins. YgaP is the only membrane-integrated rhodanese in E. coli. The sulfur transfer process has been characterized by various studies. However, the mechanism of the outward transportation of SCN- remains unclear. In this work, we examined the fluorescence lifetime and anisotropy of site-specific incorporated unnatural amino acid 7-HC to study the conformational change of YgaP upon SCN- binding. We also compared the fluorescence changes between detergent-wrapped environment in DPC and intact native membrane environment in SMA. Our results suggested the presence of at least two different conformations in YgaP protein. Both the residues in the middle of TMH2 and the residues near extracellular side play important roles in the binding and/or output of SCN-. SMA is a good material to reflect the in situ conformation changes of protein than micelles.
Fluorescence lifetime and anisotropy has become a prevalent tool to detect the structure change and motility property of proteins. YgaP is the only membrane-integrated rhodanese in E. coli. The sulfur transfer process has been characterized by various studies. However, the mechanism of the outward transportation of SCN- remains unclear. In this work, we examined the fluorescence lifetime and anisotropy of site-specific incorporated unnatural amino acid 7-HC to study the conformational change of YgaP upon SCN- binding. We also compared the fluorescence changes between detergent-wrapped environment in DPC and intact native membrane environment in SMA. Our results suggested the presence of at least two different conformations in YgaP protein. Both the residues in the middle of TMH2 and the residues near extracellular side play important roles in the binding and/or output of SCN-. SMA is a good material to reflect the in situ conformation changes of protein than micelles.
2018, 29(10): 1517-1520
doi: 10.1016/j.cclet.2018.01.054
Abstract:
Hypochlorite anion is a ubiquitous reactive molecule in the terminal disinfection systems, inflammatory stress and immune systems. Thus, rapid and visual monitoring ClO- in water and biological samples is very meaningful for water quality safety and toxicity assessment of contaminants. Herein, a colorimetric and fluorometric probe (Rh-ClO) based on rhodamine B fluorophore and thiophene-2-carbohydrazide has been unveiled and successfully utilized for ClO- detection in water samples and HeLa cells. Upon addition of ClO-, color changes of solution from colorless to pink were immediately visible to the nakedeyes, meanwhile, brilliant red fluorescence was observed under excited at UV light (365 nm). Rh-ClO displayed high selectivity and sensitivity for ClO-, and the detection limit was 7 njmol/L calculated from the fluorescence titration. With the aid of its merits including rapid response to ClO- within 10 s, Rh-ClO and its test paper could successfully detect ClO- in water. Additionally, HeLa cells image co-stained with Rh-ClO and Rh123 demonstrated that Rh-ClO possessed excellent and fast cell-membrane permeability and mitochondrion-targetability. It was clearly confirmed that Rh-ClO would be a promising probe for rapid tracking of ClO- in water samples and in mitochondria of living cells.
Hypochlorite anion is a ubiquitous reactive molecule in the terminal disinfection systems, inflammatory stress and immune systems. Thus, rapid and visual monitoring ClO- in water and biological samples is very meaningful for water quality safety and toxicity assessment of contaminants. Herein, a colorimetric and fluorometric probe (Rh-ClO) based on rhodamine B fluorophore and thiophene-2-carbohydrazide has been unveiled and successfully utilized for ClO- detection in water samples and HeLa cells. Upon addition of ClO-, color changes of solution from colorless to pink were immediately visible to the nakedeyes, meanwhile, brilliant red fluorescence was observed under excited at UV light (365 nm). Rh-ClO displayed high selectivity and sensitivity for ClO-, and the detection limit was 7 njmol/L calculated from the fluorescence titration. With the aid of its merits including rapid response to ClO- within 10 s, Rh-ClO and its test paper could successfully detect ClO- in water. Additionally, HeLa cells image co-stained with Rh-ClO and Rh123 demonstrated that Rh-ClO possessed excellent and fast cell-membrane permeability and mitochondrion-targetability. It was clearly confirmed that Rh-ClO would be a promising probe for rapid tracking of ClO- in water samples and in mitochondria of living cells.
2018, 29(10): 1521-1527
doi: 10.1016/j.cclet.2018.05.020
Abstract:
Over the past few decades, the determination of antioxidant activity by chemical probe has been widely reported, but in vivo evaluation via model organisms of Drosophila melanogaster and rapid discovery system has not been studied adequately. In this study, we determined the antioxidant activity of lees and demonstrated the ability of compounds in lees to scavenge H2O2 in vitro and in vivo by different chemical probes. Lees increased the ability of Drosophila against oxidative stress and antioxidant enzyme activity in vivo. Five ingredients of organic acids and flavones in lees extract that rapidly scavenged H2O2 were revealed by a post-column-derived HPLC-UV-FLD system based on 4-hydroxyphenylacetic acid (PHPAA) chemiluminescence. Additionally, another fluorescent probe, N-borylbenzyloxycarbonyl-3, 7-dihydroxyphenoxazine (NBCD), was selected to evaluate the reactive oxygen species (ROS) scavenging capacity of lees in living Drosophila melanogaster using a microfluidic injection test coupled with microscopic imaging analysis, and similar effects were observed in flies when they were treated with tartaric acid and caffeic acid. The results demonstrated that the novel integrated system was suitable for screening and evaluating antioxidant ingredients from natural products.
Over the past few decades, the determination of antioxidant activity by chemical probe has been widely reported, but in vivo evaluation via model organisms of Drosophila melanogaster and rapid discovery system has not been studied adequately. In this study, we determined the antioxidant activity of lees and demonstrated the ability of compounds in lees to scavenge H2O2 in vitro and in vivo by different chemical probes. Lees increased the ability of Drosophila against oxidative stress and antioxidant enzyme activity in vivo. Five ingredients of organic acids and flavones in lees extract that rapidly scavenged H2O2 were revealed by a post-column-derived HPLC-UV-FLD system based on 4-hydroxyphenylacetic acid (PHPAA) chemiluminescence. Additionally, another fluorescent probe, N-borylbenzyloxycarbonyl-3, 7-dihydroxyphenoxazine (NBCD), was selected to evaluate the reactive oxygen species (ROS) scavenging capacity of lees in living Drosophila melanogaster using a microfluidic injection test coupled with microscopic imaging analysis, and similar effects were observed in flies when they were treated with tartaric acid and caffeic acid. The results demonstrated that the novel integrated system was suitable for screening and evaluating antioxidant ingredients from natural products.
2018, 29(10): 1528-1532
doi: 10.1016/j.cclet.2018.02.011
Abstract:
Cancer activated protein-inorganic nanoparticles can be cancer targeting turn-on imaging and therapy agents. Although various techniques were successfully employed for development of hybrid proteininorganic nanoparticles, cancer cell activated protein-inorganic nanoparticles have been challengeable. Herein, a cancer cell responsive nanoparticle (PDAMn-CuS@BSA-FA, NPs) was constructed and characterized. It is found that the quenching interaction of dyes (PDA) and central metal in NPs can be adjusted by CH3O-PEG-phosphatide or the cancer cells, hence, NPs showed turn-on fluorescence emission with the titration of CH3O-PEG-phosphatide. In particular, breast cancer cells lysis can switch on the green emission greatly, while normal cells show less effect. Breast cancer cells turn-on fluorescence imaging and mitochondria targeting imaging demonstrate that the NPs can sense breast cancer cells and enter mitochondria. Therefore, NPs can be both breast cancer targeting nanosensor.
Cancer activated protein-inorganic nanoparticles can be cancer targeting turn-on imaging and therapy agents. Although various techniques were successfully employed for development of hybrid proteininorganic nanoparticles, cancer cell activated protein-inorganic nanoparticles have been challengeable. Herein, a cancer cell responsive nanoparticle (PDAMn-CuS@BSA-FA, NPs) was constructed and characterized. It is found that the quenching interaction of dyes (PDA) and central metal in NPs can be adjusted by CH3O-PEG-phosphatide or the cancer cells, hence, NPs showed turn-on fluorescence emission with the titration of CH3O-PEG-phosphatide. In particular, breast cancer cells lysis can switch on the green emission greatly, while normal cells show less effect. Breast cancer cells turn-on fluorescence imaging and mitochondria targeting imaging demonstrate that the NPs can sense breast cancer cells and enter mitochondria. Therefore, NPs can be both breast cancer targeting nanosensor.
2018, 29(10): 1533-1536
doi: 10.1016/j.cclet.2018.08.001
Abstract:
Pure organic luminogens with efficient room temperature phosphorescence (RTP) and remarkable mechanochromism are highly desired in view of their fundamental significance and technical applications. Herein, four twisted pure organic luminogens based on benzophenone and aromatic amines were synthesized and their photophysical properties were thoroughly investigated. They exhibit crystallization-induced phosphorescence (CIP), giving bright fluorescence and phosphorescence dual emission in crystals. Upon grinding, they become amorphous and emit predominantly red-shifted fluorescence, demonstrating remarkable mechanochromism. Furthermore, three of them even demonstrate greatly enhanced emission upon grinding, which is rarely observed in twisted D-A structured luminogens.
Pure organic luminogens with efficient room temperature phosphorescence (RTP) and remarkable mechanochromism are highly desired in view of their fundamental significance and technical applications. Herein, four twisted pure organic luminogens based on benzophenone and aromatic amines were synthesized and their photophysical properties were thoroughly investigated. They exhibit crystallization-induced phosphorescence (CIP), giving bright fluorescence and phosphorescence dual emission in crystals. Upon grinding, they become amorphous and emit predominantly red-shifted fluorescence, demonstrating remarkable mechanochromism. Furthermore, three of them even demonstrate greatly enhanced emission upon grinding, which is rarely observed in twisted D-A structured luminogens.
2018, 29(10): 1537-1540
doi: 10.1016/j.cclet.2018.08.003
Abstract:
Four crystals A-D based on a structurally simple ESIPT-active molecule 4MPP were obtained by subtly controlling the crystallization conditions. Notably, crystals A and C display single emission bands, which correspond to the keto* (K*) and enol* (E*) emission, respectively. B and D exhibit dual emission with different proportion of E*/K* emissions while D sucessfully achieves white emssion. The distinctively different emission properties of A-D is mainly because of the change in crystal structures. In addition, A displays amplified spontaneous emission, which indicates its potential as single crystal lasers.
Four crystals A-D based on a structurally simple ESIPT-active molecule 4MPP were obtained by subtly controlling the crystallization conditions. Notably, crystals A and C display single emission bands, which correspond to the keto* (K*) and enol* (E*) emission, respectively. B and D exhibit dual emission with different proportion of E*/K* emissions while D sucessfully achieves white emssion. The distinctively different emission properties of A-D is mainly because of the change in crystal structures. In addition, A displays amplified spontaneous emission, which indicates its potential as single crystal lasers.
2018, 29(10): 1541-1543
doi: 10.1016/j.cclet.2017.12.021
Abstract:
Luminescent cocrystals have been received much attention in fluorescence imaging and sensor application. In this work, we report that the high-quality chiral luminescent cocrystal can be obtained through a molecular self-assembly process of 2, 2'-binaphthol and 2-(3-pyridyl)-1H-benzimidazole. The assembly modes and stacking fashions of as-obtained cocrystal were determined by single crystal X-ray diffractometer. The structure and optical properties of the cocrystals were characterized by fluorescence emission, fluorescence decay, Raman and circular dichroism spectra. The results show that both the pristine co-assembled units (R-BINOL and S-BINOL) give rise to the R conformation within the final cocrystal, suggesting that the formation of cocrystal can be an effective way to achieve R/S-isomeric transformation of 2, 2'-binaphthol. It is also expected that the co-crystallization approach has much flexibility and potential applications for the design and selective formation of chiral luminescent materials.
Luminescent cocrystals have been received much attention in fluorescence imaging and sensor application. In this work, we report that the high-quality chiral luminescent cocrystal can be obtained through a molecular self-assembly process of 2, 2'-binaphthol and 2-(3-pyridyl)-1H-benzimidazole. The assembly modes and stacking fashions of as-obtained cocrystal were determined by single crystal X-ray diffractometer. The structure and optical properties of the cocrystals were characterized by fluorescence emission, fluorescence decay, Raman and circular dichroism spectra. The results show that both the pristine co-assembled units (R-BINOL and S-BINOL) give rise to the R conformation within the final cocrystal, suggesting that the formation of cocrystal can be an effective way to achieve R/S-isomeric transformation of 2, 2'-binaphthol. It is also expected that the co-crystallization approach has much flexibility and potential applications for the design and selective formation of chiral luminescent materials.
