A molybdenum disulfide/gold nanorod composite-based electrochemical immunosensor for sensitive and quantitative detection of microcystin-LR in environmental samples

A sensitive electrochemical immunosensor based on a molybdenum disulfide (MoS2) and gold nanorods (AuNRs) composite was developed for the detection of microcystin-LR (MC-LR). The immunosensor was constructed by immobilizing MC-LR antibody on the MoS2/AuNRs nanocomposite modified gold electrode. Using a competitive immunoassay format, the coated MC-LR antibody competed for MC-LR antigen with added target MC-LR, forming an antibody-antigen immunocomplex. Subsequently, horseradish peroxidase-labeled anti-MC-LR antibody (HRP-Ab(2)) was captured and detected. Under optimal conditions, the immunosensor exhibited a linear response to MC-LR ranging from 0.01 to 20 mu g L-1 with a detection limit of 5 ng L-1 at a signal to noise of 3. This electrochemical immunosensor showed good performance with high sensitivity, good stability, accepted reusability and promising applications in routine water quality monitoring for various toxins. (C) 2017 Elsevier B.V. All rights reserved.