Utilising the affinity and high combination ability between silver nanocubes and amino group (–NH2), a novel electrochemical immunosensor was constructed for the ultrasensitive detection of microcystin-LR (MC-LR) based on G4-polyamidoamine (PAMAM) dendrimer and Ag nanocubes
as immobilised substrate of anti-MC-LR. G4-PAMAM dendrimers were covalently bound on the chitosan (CHIT) – modified electrode by glutaraldehyde (GA), providing abundant amino groups to absorb much more Ag nanocubes comparing without using PAMAM. Subsequently, antibodies of MC-LR were
immobilised with highly dense through Ag-NH2. K3Fe(CN)6/K4Fe(CN)6 was used as electroactive redox probe. Ag nanocubes/PAMAM can enhance the antibody loading amount, which would bind more MC-LR and hinder the electron transfer of K3Fe(CN)6/K4Fe(CN)6.
Differential pulse voltammetry (DPV) was employed to evaluate the analytical performance of the fabricated signal-off immunosensor. The response current had negative correlation with the concentration of MC-LR. The linear range covered was from 0.05 ng/mL to 25 μg/mL with detection
limit (DL) of 0.017 ng/mL at 3σ. The proposed approach showed high specificity for the detection of MC-LR, with acceptable reproducibility, stability and reliability. Compared with the enzyme-linked immunoassay (ELISA) method by analyzing real water samples from Dian Lake, this
immunosensor revealed acceptable accuracy with a relative error of 12.7%, indicating a potential alternative method for MC-LR detection in water sample.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming, PR China
Environmental Analysis and Testing Center, Yunnan Institute of Environmental Science, Kunming, PR China
February 19, 2016
More about this publication?