A novel, sensitive anodic stripping volammetric immunoassay was developed based on silver-enhanced immuno-gold label. The immunoreaction was performed in a polystyrene microwell by using the sandwich format. Primary a...A novel, sensitive anodic stripping volammetric immunoassay was developed based on silver-enhanced immuno-gold label. The immunoreaction was performed in a polystyrene microwell by using the sandwich format. Primary antibodies specific for C-3(complement Ⅲ) were adsorbed passively on the walls of a polystyrene microwell. The C-3 analyte was first captured by the primary antibody and then sandwiched by a secondary colloidal gold-labeled antibody. The addition of the silver enhancement solution results in the precipitation of a large amount of silver on colloidal gold labels due to the catalytic reduction which, after silver metal dissolution in an acidic solution, was determined by anodic stripping voltammetry(ASV) at a glassy-carbon electrode. The influence of some immunoassay conditions upon the anodic stripping peak current was examined and optimized. The anodic stripping peak current depended linearly on the logarithm of C-3 mass concentration over the range of 7.2 ng/mL to 7.33 μg/mL and a detection limit as low as 7ng/mL is achieved. The anodic stripping volammetric immunoassay was applied to the determination of C-3 concentration in human serum with satisfactory results.展开更多
An ion-selective electrode(ISE)-based immunoassay has been innovatively designed for the sensitive detection of liver cancer biomarker(alpha-fetoprotein,AFP),using metal sulfide quantum dot(QD)-based nano labels.Cd S ...An ion-selective electrode(ISE)-based immunoassay has been innovatively designed for the sensitive detection of liver cancer biomarker(alpha-fetoprotein,AFP),using metal sulfide quantum dot(QD)-based nano labels.Cd S QDs-aggregated PAMAM dendrimer(QD-DE)was first synthesized and functionalized with polyclonal rabbit anti-human AFP antibodies.Thereafter,a sandwich immunoreaction was implemented on monoclonal mouse anti-human AFP antibody-coated microplate by using antibody-functionalized QD-DE as the secondary antibody.Accompanying the immunocomplex,subsequent potentiometric detection of cadmium ion dissolved from the QD-DE under acidic condition was conducted on a portable cadmium ion-selective electrode(Cd-ISE).Results revealed that the electrode potential of the Cd-ISE increased with the increment of AFP concentration from 0.1 to 100 ng m L^(-1)at a detection limit(LOD)of 68 pg m L^(-1).The relative standard deviations(RSD)were below9.09%and 10.54%for the intra-and inter-assay,respectively.Additionally,six human serum specimens were determined on CdISE-based immunosensor by using commercial human AFP ELISA kit as the reference,and gave good relationship between two methods.Importantly,Cd-ISE-based immunoassay offers the promise for simple and cost-effective screening of disease-related biomarkers.展开更多
文摘A novel, sensitive anodic stripping volammetric immunoassay was developed based on silver-enhanced immuno-gold label. The immunoreaction was performed in a polystyrene microwell by using the sandwich format. Primary antibodies specific for C-3(complement Ⅲ) were adsorbed passively on the walls of a polystyrene microwell. The C-3 analyte was first captured by the primary antibody and then sandwiched by a secondary colloidal gold-labeled antibody. The addition of the silver enhancement solution results in the precipitation of a large amount of silver on colloidal gold labels due to the catalytic reduction which, after silver metal dissolution in an acidic solution, was determined by anodic stripping voltammetry(ASV) at a glassy-carbon electrode. The influence of some immunoassay conditions upon the anodic stripping peak current was examined and optimized. The anodic stripping peak current depended linearly on the logarithm of C-3 mass concentration over the range of 7.2 ng/mL to 7.33 μg/mL and a detection limit as low as 7ng/mL is achieved. The anodic stripping volammetric immunoassay was applied to the determination of C-3 concentration in human serum with satisfactory results.
基金supported by the National Natural Science Foundation of China (21675029, 21665009, 21475025)the Key Joint Project for Health Education of Fujian Province (WKJ2016-2-15)the Program for Changjiang Scholars and Innovative Research Team in University (IRT15R11)
文摘An ion-selective electrode(ISE)-based immunoassay has been innovatively designed for the sensitive detection of liver cancer biomarker(alpha-fetoprotein,AFP),using metal sulfide quantum dot(QD)-based nano labels.Cd S QDs-aggregated PAMAM dendrimer(QD-DE)was first synthesized and functionalized with polyclonal rabbit anti-human AFP antibodies.Thereafter,a sandwich immunoreaction was implemented on monoclonal mouse anti-human AFP antibody-coated microplate by using antibody-functionalized QD-DE as the secondary antibody.Accompanying the immunocomplex,subsequent potentiometric detection of cadmium ion dissolved from the QD-DE under acidic condition was conducted on a portable cadmium ion-selective electrode(Cd-ISE).Results revealed that the electrode potential of the Cd-ISE increased with the increment of AFP concentration from 0.1 to 100 ng m L^(-1)at a detection limit(LOD)of 68 pg m L^(-1).The relative standard deviations(RSD)were below9.09%and 10.54%for the intra-and inter-assay,respectively.Additionally,six human serum specimens were determined on CdISE-based immunosensor by using commercial human AFP ELISA kit as the reference,and gave good relationship between two methods.Importantly,Cd-ISE-based immunoassay offers the promise for simple and cost-effective screening of disease-related biomarkers.
