The mercury species in the ocean(MeHg,Hg^(2+))will be enriched in marine organisms and threaten human health through the food chain.While the excessive H_(2)O_(2)in the metabolic process will produce hydroxyl radicals...The mercury species in the ocean(MeHg,Hg^(2+))will be enriched in marine organisms and threaten human health through the food chain.While the excessive H_(2)O_(2)in the metabolic process will produce hydroxyl radicals and accelerate the aging of human cells,causing a series of diseases.Hence,the cost-effective and rapid detection of mercury and H_(2)O_(2)is of urgent requirement and significance.Here,we synthesized emerging graphitic carbon nitride quantum dots(g-CNQDs)with high fluorescence quantum yield(FLQY)of 42.69%via a bottom-up strategy by a facile one-step hydrothermal method.The g-CNQDs can detect the H_(2)O_(2)and Hg^(2+)through the fluorescence quenching effect between g-CNQDs and detected substances.With the presence of KI,g-CNQDs show concentration-dependent fluorescence toward H_(2)O_(2),with a wide detection range of 1–1000μmolL^(-1)and a low detection limit of 0.23μmolL^(-1).The g-CNQDs also show sensitivity toward Hg^(2+)with a detection range of 0–0.1μmolL^(-1)and a detection limit of 0.038μmolL^(-1).This dual-function detection of g-CNQDs has better practical application capability compared to other quantum dot detection.This study may provide a new strategy for g-CNQDs preparation and construct a fluorescence probe that can be used in various systems involving H_(2)O_(2)and Hg^(2+),providing better support for future bifunctional or multifunction studies.展开更多
Cysteine (CSH) readily stabilizes cadmium sulfide quantum dots (CdS QDs) that grow in aqueous buffered solutions. The oxidation of CSH by hydrogen peroxide (H202) at room temperature yields cystine (CSSC), whi...Cysteine (CSH) readily stabilizes cadmium sulfide quantum dots (CdS QDs) that grow in aqueous buffered solutions. The oxidation of CSH by hydrogen peroxide (H202) at room temperature yields cystine (CSSC), which is less efficient in stabilizing CdS QDs compared to CSH. Herein, we demonstrate that such oxidation causes a decrease in the formation rate of CSH-capped CdS QDs from Cd^2+ and S^2- ions. For the first time, we combined the oxidation of CSH with the glucose oxidase (GOx)-assisted biocatalytic oxidation of D-glucose, which leads to a buildup of H2O2 in the reaction mixture. The enzymatically modulated in situ growth of CdS QDs was monitored using two techniques: fluorescence spectroscopy and photoelectrochemical (PEC) analysis. This system enables quantification of GOx and glucose in human serum.展开更多
Abnormal expression of hydrogen peroxide(H_(2)O_(2))indicates the disorder of cell functions and is able to induce the occurrence and deterioration of numerous diseases.However,limited by its low concentration under p...Abnormal expression of hydrogen peroxide(H_(2)O_(2))indicates the disorder of cell functions and is able to induce the occurrence and deterioration of numerous diseases.However,limited by its low concentration under pathophysiological conditions,intracellular H_(2)O_(2) is still difficult to be determined to date.Herein,to achieve sensitive quantification of H_(2)O_(2) in cells,CIS/ZnS/ZnS quantum dots(CIS/d-ZnS QDs)are retrofitted with ZnO shells via self-passivation.Different from the traditional self-passivation of QDs,self-passivation of CIS/d-ZnS QDs is realized facilely without the assistance of additional cation ions,which improves optical properties of QDs and equips the QDs with a sensing layer.As a result,the CIS/d-ZnS/ZnO QDs exhibit enhanced fluorescence emission and stability.Relying on the decomposition of ZnO and ZnS shells in the presence of H_(2)O_(2),aggregated QDs reveal exciton energy transfer effect,resulting in fluorescence quenching.On a basis of this principle,a fluorescence H_(2)O_(2) sensor is further established with the CIS/d-ZnS/ZnO QDs.To be noted,since the equipped ZnO shells are more susceptible to H2O2 than original ZnS shells,analytical performance of the fluorescence sensor is remarkably promoted by the self-passivation of QDs.Accordingly,H_(2)O_(2) can be measured in 5 orders of magnitude with a limit of detection(LOD)of 0.46 nM.Furthermore,because the ZnO shells improve H2O2-responsive selectivity and sensitivity,variation of H_(2)O_(2) in cells can also be quantified with the CIS/d-ZnS/ZnO QDs.In this work,sensitive detection of intracellular H_(2)O_(2) is enabled by equipping QDs with a sensing layer,which provides an alternative perspective of functionalizing nanomaterials for analytical applications.展开更多
基金support from the Natural Science Foundation of Shandong Province(No.ZR2021 MB075)National Natural Science Foundation of China(No.51602297)the Opening Fund of State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering(No.2021-K53).
文摘The mercury species in the ocean(MeHg,Hg^(2+))will be enriched in marine organisms and threaten human health through the food chain.While the excessive H_(2)O_(2)in the metabolic process will produce hydroxyl radicals and accelerate the aging of human cells,causing a series of diseases.Hence,the cost-effective and rapid detection of mercury and H_(2)O_(2)is of urgent requirement and significance.Here,we synthesized emerging graphitic carbon nitride quantum dots(g-CNQDs)with high fluorescence quantum yield(FLQY)of 42.69%via a bottom-up strategy by a facile one-step hydrothermal method.The g-CNQDs can detect the H_(2)O_(2)and Hg^(2+)through the fluorescence quenching effect between g-CNQDs and detected substances.With the presence of KI,g-CNQDs show concentration-dependent fluorescence toward H_(2)O_(2),with a wide detection range of 1–1000μmolL^(-1)and a low detection limit of 0.23μmolL^(-1).The g-CNQDs also show sensitivity toward Hg^(2+)with a detection range of 0–0.1μmolL^(-1)and a detection limit of 0.038μmolL^(-1).This dual-function detection of g-CNQDs has better practical application capability compared to other quantum dot detection.This study may provide a new strategy for g-CNQDs preparation and construct a fluorescence probe that can be used in various systems involving H_(2)O_(2)and Hg^(2+),providing better support for future bifunctional or multifunction studies.
文摘Cysteine (CSH) readily stabilizes cadmium sulfide quantum dots (CdS QDs) that grow in aqueous buffered solutions. The oxidation of CSH by hydrogen peroxide (H202) at room temperature yields cystine (CSSC), which is less efficient in stabilizing CdS QDs compared to CSH. Herein, we demonstrate that such oxidation causes a decrease in the formation rate of CSH-capped CdS QDs from Cd^2+ and S^2- ions. For the first time, we combined the oxidation of CSH with the glucose oxidase (GOx)-assisted biocatalytic oxidation of D-glucose, which leads to a buildup of H2O2 in the reaction mixture. The enzymatically modulated in situ growth of CdS QDs was monitored using two techniques: fluorescence spectroscopy and photoelectrochemical (PEC) analysis. This system enables quantification of GOx and glucose in human serum.
基金This work was supported by the National Natural Science Foundation of China(Nos.21625502,21974070,and 22176099)the Natural Science Foundation of Jiangsu Province of China(Nos.BK20191367 and BK20192008).
文摘Abnormal expression of hydrogen peroxide(H_(2)O_(2))indicates the disorder of cell functions and is able to induce the occurrence and deterioration of numerous diseases.However,limited by its low concentration under pathophysiological conditions,intracellular H_(2)O_(2) is still difficult to be determined to date.Herein,to achieve sensitive quantification of H_(2)O_(2) in cells,CIS/ZnS/ZnS quantum dots(CIS/d-ZnS QDs)are retrofitted with ZnO shells via self-passivation.Different from the traditional self-passivation of QDs,self-passivation of CIS/d-ZnS QDs is realized facilely without the assistance of additional cation ions,which improves optical properties of QDs and equips the QDs with a sensing layer.As a result,the CIS/d-ZnS/ZnO QDs exhibit enhanced fluorescence emission and stability.Relying on the decomposition of ZnO and ZnS shells in the presence of H_(2)O_(2),aggregated QDs reveal exciton energy transfer effect,resulting in fluorescence quenching.On a basis of this principle,a fluorescence H_(2)O_(2) sensor is further established with the CIS/d-ZnS/ZnO QDs.To be noted,since the equipped ZnO shells are more susceptible to H2O2 than original ZnS shells,analytical performance of the fluorescence sensor is remarkably promoted by the self-passivation of QDs.Accordingly,H_(2)O_(2) can be measured in 5 orders of magnitude with a limit of detection(LOD)of 0.46 nM.Furthermore,because the ZnO shells improve H2O2-responsive selectivity and sensitivity,variation of H_(2)O_(2) in cells can also be quantified with the CIS/d-ZnS/ZnO QDs.In this work,sensitive detection of intracellular H_(2)O_(2) is enabled by equipping QDs with a sensing layer,which provides an alternative perspective of functionalizing nanomaterials for analytical applications.