Nanochannels have made great progress and are a promising platform for detecting a series of targets.However,most nanochannels are modified on the inner wall,while ignoring the outer surface.Here,we modified the outer...Nanochannels have made great progress and are a promising platform for detecting a series of targets.However,most nanochannels are modified on the inner wall,while ignoring the outer surface.Here,we modified the outer surface of nanochannels with hydrogel.Different from other reported outer-surface modification methods,we directly cover nanochannels with hydrogel to form heterogeneous membrane.The selected hydrogel hardly adsorbs other ions and shows specific adsorption for Cr(VI).The adsorption sites in hydrogel are homogeneous,and Cr(VI)adsorption onto hydrogel is endothermic and spontaneous.The charge in hydrogel changes after Cr(VI)adsorption,and the resulting current changes can be used for the detection of Cr(VI)with the detection limit of 10−11 mol/L.Our platform is expected to be used for Cr(VI)detection in living organisms,especially within cells.This work provides a new approach for outer-surface modification of nanochannels and offers a new choice for nanochannel detection platforms.展开更多
Novel C-BiOCl/Bi_(2)S_(3) composites are prepared by hydrothermal C doping in BiOCl and in-situ growth of Bi_(2)S_(3) on C-BiOCl.Compared with BiOCl,C-BiOCl has a larger exposed surface area and can effectively absorb...Novel C-BiOCl/Bi_(2)S_(3) composites are prepared by hydrothermal C doping in BiOCl and in-situ growth of Bi_(2)S_(3) on C-BiOCl.Compared with BiOCl,C-BiOCl has a larger exposed surface area and can effectively absorb visible light.The construction of a heterojunction in C-BiOCl/Bi_(2)S_(3) further promotes the separation and transfer of photogenerated carriers.With improved photoelectric properties,the optimized 5C-BiOCl/5Bi_(2)S_(3) is applied as a dual-functional composite for photoelectrochemical(PEC)detection and photocatalytic(PC)reduction of Cr(VI).The 5C-BiOCl/5Bi_(2)S_(3) shows a linear range of 0.02-80μM for PEC cathodic detection of Cr(VI)with a detection limit of 0.01628μM.Additionally,99.5%of Cr(VI)can be removed via absorption and PC reduction by 5C-BiOCl/5Bi_(2)S_(3),with the reduction rate constant(k)336 times higher than that of BiOCl.展开更多
A method is described here for the quickly(<30 s) accurate determination of Cr(VI)(Cr_2O_7^(2-)), based on fluorescent probes gold nanodots(AuNDs, excitation/emission peaks at 395/604 nm) coated with glutathione(GS...A method is described here for the quickly(<30 s) accurate determination of Cr(VI)(Cr_2O_7^(2-)), based on fluorescent probes gold nanodots(AuNDs, excitation/emission peaks at 395/604 nm) coated with glutathione(GSH). The fluorescence of the AuNDs responses linearly to Cr(VI) concentrations, ranging widely from 1 nM to 10 m M with detection limit as low as 0.35 nM. At the same time, the AuNDs is demonstrated highly selective for Cr(VI) detection over other acid group ions and metal ions without any masking reagent. These make probability for practical use. The quenching mechanism is investigated deeply via fluorescent lifetime, XPS and TEM analysis. Different from most reported quenching explanation of aggregation derived from charge attraction, these results verify the redox reaction between Cr_2O_7^(2-)and sulfhydryl(–S) of GSH. The Au(I)–S bonds of AuNDs broke, accompanies with the oxidation of –S to form S–S bonds. As a result, AuNDs cross linked to each other. In the end, the fluorescence quenched. Attractively, the present study provides a new strategy for pollutant detection, such as from harmful Cr(VI) of Cr_2O_7^(2-)to nontoxic Cr(III).展开更多
基金supported by the National Natural Science Foundation of China(No.22090050)the National Key R&D Program of China(No.2021YFA1200403)the Joint National Natural Science Foundation of China-Israel Science Foundation(NSFC-ISF)Research Grant Program(No.22161142020).
文摘Nanochannels have made great progress and are a promising platform for detecting a series of targets.However,most nanochannels are modified on the inner wall,while ignoring the outer surface.Here,we modified the outer surface of nanochannels with hydrogel.Different from other reported outer-surface modification methods,we directly cover nanochannels with hydrogel to form heterogeneous membrane.The selected hydrogel hardly adsorbs other ions and shows specific adsorption for Cr(VI).The adsorption sites in hydrogel are homogeneous,and Cr(VI)adsorption onto hydrogel is endothermic and spontaneous.The charge in hydrogel changes after Cr(VI)adsorption,and the resulting current changes can be used for the detection of Cr(VI)with the detection limit of 10−11 mol/L.Our platform is expected to be used for Cr(VI)detection in living organisms,especially within cells.This work provides a new approach for outer-surface modification of nanochannels and offers a new choice for nanochannel detection platforms.
基金supported by the National Natural Science Foundation of China(Nos.51901222,41827805)the CAS Pioneer Hundred Talents Program,and the Shandong Province Higher Educational Program for Introduction and Cultivation of Young Innovative Talents(2021).
文摘Novel C-BiOCl/Bi_(2)S_(3) composites are prepared by hydrothermal C doping in BiOCl and in-situ growth of Bi_(2)S_(3) on C-BiOCl.Compared with BiOCl,C-BiOCl has a larger exposed surface area and can effectively absorb visible light.The construction of a heterojunction in C-BiOCl/Bi_(2)S_(3) further promotes the separation and transfer of photogenerated carriers.With improved photoelectric properties,the optimized 5C-BiOCl/5Bi_(2)S_(3) is applied as a dual-functional composite for photoelectrochemical(PEC)detection and photocatalytic(PC)reduction of Cr(VI).The 5C-BiOCl/5Bi_(2)S_(3) shows a linear range of 0.02-80μM for PEC cathodic detection of Cr(VI)with a detection limit of 0.01628μM.Additionally,99.5%of Cr(VI)can be removed via absorption and PC reduction by 5C-BiOCl/5Bi_(2)S_(3),with the reduction rate constant(k)336 times higher than that of BiOCl.
基金supported by the National Natural Science Foundation of China(51373061,21304090)Emphases Science and Technology Research Program of Jilin Province Science and Technology Development Plan(20180201060SF)Science Foundation of China University of Petroleum,Beijing(2462017YJRC027)
文摘A method is described here for the quickly(<30 s) accurate determination of Cr(VI)(Cr_2O_7^(2-)), based on fluorescent probes gold nanodots(AuNDs, excitation/emission peaks at 395/604 nm) coated with glutathione(GSH). The fluorescence of the AuNDs responses linearly to Cr(VI) concentrations, ranging widely from 1 nM to 10 m M with detection limit as low as 0.35 nM. At the same time, the AuNDs is demonstrated highly selective for Cr(VI) detection over other acid group ions and metal ions without any masking reagent. These make probability for practical use. The quenching mechanism is investigated deeply via fluorescent lifetime, XPS and TEM analysis. Different from most reported quenching explanation of aggregation derived from charge attraction, these results verify the redox reaction between Cr_2O_7^(2-)and sulfhydryl(–S) of GSH. The Au(I)–S bonds of AuNDs broke, accompanies with the oxidation of –S to form S–S bonds. As a result, AuNDs cross linked to each other. In the end, the fluorescence quenched. Attractively, the present study provides a new strategy for pollutant detection, such as from harmful Cr(VI) of Cr_2O_7^(2-)to nontoxic Cr(III).
