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
Chromium is a harmful contaminant showing mutagenicity and carcinogenicity.Therefore,detection of chromium requires the development of low-cost and high-sensitivity sensors.Herein,blue-fluorescent carbon quantum dots ...Chromium is a harmful contaminant showing mutagenicity and carcinogenicity.Therefore,detection of chromium requires the development of low-cost and high-sensitivity sensors.Herein,blue-fluorescent carbon quantum dots were synthesized by one-step hydrothermal method from alkali-soluble Poria cocos polysaccharide,which is green source,cheap and easy to obtain,and has no pharmacological activity due to low water solubility.These carbon quantum dots exhibit good fluorescence stability,water solubility,anti-interference and low cytotoxicity,and can be specifically combined with the detection of Cr(Ⅵ)to form a non-fluorescent complex that causes fluorescence quenching,so they can be used as a label-free nanosensor.High-sensitivity detection of Cr(Ⅵ)was achieved through internal filtering and static quenching effects.The fluorescence quenching degree of carbon dots fluorescent probe showed a good linear relationship with Cr(Ⅵ)concentration in the range of 1-100μM.The linear equation was F;/F=0.9942+0.01472[Cr(Ⅵ)](R;=0.9922),and the detection limit can be as low as 0.25μM(S/N=3),which has been successfully applied to Cr(Ⅵ)detection in actual water samples herein.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financially supported by the Natural Science Foundation of Anhui University of Chinese Medicine (Grant No.: 2018zrzd04)Anhui Provincial Natural Science Foundation (Grant No.: 1908085QH351)+2 种基金Major Science and Technology Projects of Anhui Province (Grant No.: 18030801131)National Key Research and Development Project (Grant No.: 2017YFC1701600)Anhui Province’s Central Special Fund for Local Science and Technology Development (Grant No.: 201907d07050002)
文摘Chromium is a harmful contaminant showing mutagenicity and carcinogenicity.Therefore,detection of chromium requires the development of low-cost and high-sensitivity sensors.Herein,blue-fluorescent carbon quantum dots were synthesized by one-step hydrothermal method from alkali-soluble Poria cocos polysaccharide,which is green source,cheap and easy to obtain,and has no pharmacological activity due to low water solubility.These carbon quantum dots exhibit good fluorescence stability,water solubility,anti-interference and low cytotoxicity,and can be specifically combined with the detection of Cr(Ⅵ)to form a non-fluorescent complex that causes fluorescence quenching,so they can be used as a label-free nanosensor.High-sensitivity detection of Cr(Ⅵ)was achieved through internal filtering and static quenching effects.The fluorescence quenching degree of carbon dots fluorescent probe showed a good linear relationship with Cr(Ⅵ)concentration in the range of 1-100μM.The linear equation was F;/F=0.9942+0.01472[Cr(Ⅵ)](R;=0.9922),and the detection limit can be as low as 0.25μM(S/N=3),which has been successfully applied to Cr(Ⅵ)detection in actual water samples herein.
