Aptamer nanobiosensor for algal toxin in water

Abstract

Algal blooms are the source of cyanotoxins linked to eutrophication in water reservotrs worldwide. Microcystin-leucine and arginine (MC-LR) is a naturally occurring toxin produced by cyanobacteria (blue-green algae bloom) in drinking water reservoirs. It is one of a large family of microcyst ins and is considered the most toxic compound of its family. Microcystins (MCs) are potently hepatotoxic, nephrotoxic as well as carcinogenic. Consequently, these MCs pose a momentous threat to tourism, agriculture and animal health. Although there are several predominant analytical techniques for MCs detection such as bioassay, enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC), biosensors tend to offer the advantage of reproducibility, portability as well as rapid and accurate detection. In this study a novel, simple and sensitive electrochemical aptasensor was developed for MC-LR detection. The aptasensor platform consisted of a one-pot electro-polymerized nanocomposite of poly(vinylsulfonate) (PV-S03-), poly(2, 5-dimethoxyaniline) (PDMA) and silver nanoparticles (AgNPs) electrochemically attached to a glassy carbon electrode (GCE). The as-prepared GCEI PDMAI rvso.. AgO nanocomposite was used as the immobilization interface onto which the MC-LR based aptamers was drop-coated. The PDMAI PV-S03 -I AgO nanocomposite was characterized by Cyclic Voltammetry (CV), Fourier Transform Infrared spectroscopy (FTIR), UV - Vis spectroscopy, Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Electrochemical Impedance Spectroscopy (EIS).