A novel magnetic electrochemical sensor was designed for determination of lead ions based on gold na- noparticles（AuNPs）@SiO2@Fe3O4/nitrogen-doped graphene（NG） composites functionalized with L-cysteine. The Au@SiO...A novel magnetic electrochemical sensor was designed for determination of lead ions based on gold na- noparticles（AuNPs）@SiO2@Fe3O4/nitrogen-doped graphene（NG） composites functionalized with L-cysteine. The Au@SiO2@Fe3O4/NG was synthesized by the electrostatic adsorption between AuNPs and SiO2-coated Fe304 NPs（SiO2@Fe304） and the amide bond between Au@SiO2@Fe3O4 and NG. L-Cysteine was successfully functionalized on the surface of Au@SiO2@Fe3O4/NG nanocomposites via the S--Au bond between L-cysteine and AuNPs. Owing to numerous active sites in L-cysteines and high conductivity of Au@SiO2@Fe3O4/NG composites, the pro- posed electrochemical sensor exhibited a well-distributed nanostructure and high responsivity toward Pb（II）. The sensor linearly responded to Pb2＋ concentration in the range of 5-80 μg/L with a detection limit of 0.6 μg/L, indicating that this L-cysteine functionalized Au@SiO2@Fe3O4/NG composite could be a promising candidate material for the detection of Pb2＋.展开更多
Molecularly imprinted membrane-zinc porphyrin-mathacrylate（MIM-Zn-MAA）, a dual read-out sensor based on a molecularly imprinted membrane, was developed to recognize and detect dimethyl methylphosphonate （DMMP） as ...Molecularly imprinted membrane-zinc porphyrin-mathacrylate（MIM-Zn-MAA）, a dual read-out sensor based on a molecularly imprinted membrane, was developed to recognize and detect dimethyl methylphosphonate （DMMP） as an intermediate molecule of organophosphorus pesticides. The membranes were prepared via thermal polymerization of two functional monomers（zinc porphyrin and mathacrylate） on the surface of a glass slide functio- nalized with ethylene glycol dimethacrylate and azobisisobutyronitrile. The morphology of the as-synthesized MIM-Zn-MAA was determined with scanning electronic microscopy. The composite membranes exhibited macrovoid morphologies, which were affected by the functional monomers. These membranes were selectively adsorbed onto the template molecule and displayed higher adsorbing capacity toward DMMP compared with their structural analogs Changes in the fluorescent spectra were qualitatively and quantitatively monitored via fluorescence photometry. Dif- ference maps were also obtained using colorimetry before and after the reaction between MIM-Zn-MAA and DMMP at various concentrations. The maps showed a wide linear range varying from 0.1 lamol/L to 10 mmol/L with a low detection limit of 0.1 lamol/L. These preliminary results demonstrate that the as-fabricated dual read-out sensor dis- plays good sensitivity and selectivity toward DMMP, indicating its considerable potential in DMMP detection in practical applications.展开更多
A novel and highly sensitive colorimetric sensor array was developed for the detection and identification of breath volatile organic compounds（VOCs） of patients with lung cancer.Employing dimeric metalloporphyrins,m...A novel and highly sensitive colorimetric sensor array was developed for the detection and identification of breath volatile organic compounds（VOCs） of patients with lung cancer.Employing dimeric metalloporphyrins,metallosalphen complexes,and chemically responsive dyes as the sensing elements,the developed sensor array of artificial nose shows a unique pattern of colorific changes upon its exposure to eight less-reactive VOCs and their mixture gas at a concentration of 735 nmol/L within 3 min.Potential of quantitative analysis of VOCs samples was proved.A good linear relationship of 490-3675 nmol/L was obtained for benzene vapor with a detection limit of 49 nmol/L（S/N=3）.Data analysis was carried out by Hierarchical cluster analysis（HCA） and principal component analysis（PCA）.Each category of breath VOCs clusters together in the PCA score plot.No errors in classification by HCA were observed in 45 trials.Additionaly,the colorimetric sensor array showed good reproducibility under the cyclic sensing experiments.These results demonstrate that the developed colorimetric artificial nose system is an excellent sensing platform for the identification and quantitative analysis of breath VOCs of patients with lung cancer.展开更多
基金Supported by the National Natural Science Foundation of China（No.31101284）, the Graduate Research and Innovation Foundation of Chongqing, China（No.CYS17017）, the Fundamental Research Funds for the Central Universities of China （Nos. CQDXWL-2012-034, CQDXWL-2012-035, CDJPY12220001） and the Chongqing University Student Research Training Program, China（Nos.CQU-SRTP-2015497, CQU-SRTP-2015502）.
文摘A novel magnetic electrochemical sensor was designed for determination of lead ions based on gold na- noparticles（AuNPs）@SiO2@Fe3O4/nitrogen-doped graphene（NG） composites functionalized with L-cysteine. The Au@SiO2@Fe3O4/NG was synthesized by the electrostatic adsorption between AuNPs and SiO2-coated Fe304 NPs（SiO2@Fe304） and the amide bond between Au@SiO2@Fe3O4 and NG. L-Cysteine was successfully functionalized on the surface of Au@SiO2@Fe3O4/NG nanocomposites via the S--Au bond between L-cysteine and AuNPs. Owing to numerous active sites in L-cysteines and high conductivity of Au@SiO2@Fe3O4/NG composites, the pro- posed electrochemical sensor exhibited a well-distributed nanostructure and high responsivity toward Pb（II）. The sensor linearly responded to Pb2＋ concentration in the range of 5-80 μg/L with a detection limit of 0.6 μg/L, indicating that this L-cysteine functionalized Au@SiO2@Fe3O4/NG composite could be a promising candidate material for the detection of Pb2＋.
基金Supported by the National Natural Science Foundation of China（No.31101284）, the Natural Science Foundation of Chongqing City, China（No.CSTC-2011BB1209）, the Fundamental Research Funds for the Central Universities of China （Nos.CQDXWL-2012-034, CQDXWL-2012-035, CDJPY1222 0001） and the Student Research Training Program in Chongqing University, China（Nos.CQU-SRTP-2015497, CQU-SRTP-2015502）.
文摘Molecularly imprinted membrane-zinc porphyrin-mathacrylate（MIM-Zn-MAA）, a dual read-out sensor based on a molecularly imprinted membrane, was developed to recognize and detect dimethyl methylphosphonate （DMMP） as an intermediate molecule of organophosphorus pesticides. The membranes were prepared via thermal polymerization of two functional monomers（zinc porphyrin and mathacrylate） on the surface of a glass slide functio- nalized with ethylene glycol dimethacrylate and azobisisobutyronitrile. The morphology of the as-synthesized MIM-Zn-MAA was determined with scanning electronic microscopy. The composite membranes exhibited macrovoid morphologies, which were affected by the functional monomers. These membranes were selectively adsorbed onto the template molecule and displayed higher adsorbing capacity toward DMMP compared with their structural analogs Changes in the fluorescent spectra were qualitatively and quantitatively monitored via fluorescence photometry. Dif- ference maps were also obtained using colorimetry before and after the reaction between MIM-Zn-MAA and DMMP at various concentrations. The maps showed a wide linear range varying from 0.1 lamol/L to 10 mmol/L with a low detection limit of 0.1 lamol/L. These preliminary results demonstrate that the as-fabricated dual read-out sensor dis- plays good sensitivity and selectivity toward DMMP, indicating its considerable potential in DMMP detection in practical applications.
基金Supported by the National Natural Science Foundation of China（Nos.81171414, 81271930, 31171684）, the Key Technologies R＆D Program of China（No.2012BAI19B03）, the Doctoral Fund of Ministry of Education of China（No.20090191110030） and the Sharing Fund of Chongqing University＇s Large Equipment, China.
文摘A novel and highly sensitive colorimetric sensor array was developed for the detection and identification of breath volatile organic compounds（VOCs） of patients with lung cancer.Employing dimeric metalloporphyrins,metallosalphen complexes,and chemically responsive dyes as the sensing elements,the developed sensor array of artificial nose shows a unique pattern of colorific changes upon its exposure to eight less-reactive VOCs and their mixture gas at a concentration of 735 nmol/L within 3 min.Potential of quantitative analysis of VOCs samples was proved.A good linear relationship of 490-3675 nmol/L was obtained for benzene vapor with a detection limit of 49 nmol/L（S/N=3）.Data analysis was carried out by Hierarchical cluster analysis（HCA） and principal component analysis（PCA）.Each category of breath VOCs clusters together in the PCA score plot.No errors in classification by HCA were observed in 45 trials.Additionaly,the colorimetric sensor array showed good reproducibility under the cyclic sensing experiments.These results demonstrate that the developed colorimetric artificial nose system is an excellent sensing platform for the identification and quantitative analysis of breath VOCs of patients with lung cancer.
