A non-enzymatic electrochemical immunosensor for microcystin-LR rapid detection based on Ag@MSN nanoparticles

•A nonenzymatic electrochemical immunosensor based on the Ag@MSN nanoparticles was developed for the detection of MC-LR.•Ag@MSN nanoparticle which possessed an intrinsic enzyme catalytic activity similar to that of horseradish peroxidase was used to replace protein enzyme to improve the stability and sensitivity.•The method is highly sensitive with the detection limit of 0. 2 ng/mL.

A nonenzymatic electrochemical immunosensor based on the silver@ mesoporous (denoted as Ag@MSN) nanoparticles was developed for the detection of microcystin-leucine-arginine (MC-LR). Classical electrochemical immunosensor usually employs protein enzymes as biocatalysts to afford amplified signals. However, enzymes are vulnerable to proteolytic degradation, suffering from poor stability. Ag@MSN nanoparticle which possessed an intrinsic enzyme catalytic activity similar to that of horseradish peroxidase was used to replace protein enzyme to improve the stability and sensitivity. Under the optimized experimental conditions, the nonenzymatic immunosensor exhibits excellent performance (e.g., a detection limit of 0. 2 ng/mL, a linear dynamic range of 3 orders of magnitude, high specificity). With these merits, this stable, simple, sensitive and low-cost nonenzymatic electrochemical immunoassay shows promise for applications in food and environmental monitoring.

Graphical abstractA nonenzymatic electrochemical immunosensor based on the Ag@MSN nanoparticles was developed for the detection of MC-LR. Ag@MSN nanoparticle which possessed an intrinsic enzyme catalytic activity similar to that of horseradish peroxidase was used to replace protein enzyme to improve the stability and sensitivity. With these merits, this stable, simple, sensitive and low-cost nonenzymatic electrochemical immunoassay shows promise for applications in food and environmental monitoring.Figure optionsDownload full-size imageDownload as PowerPoint slide