An electrochemical deoxyribonucleic acid biosensor for rapid genotoxicity screening of chemicals

Abstract

A sensitive electrochemical biosensor based on double-stranded deoxyribonucleic acid (DNA) has been proposed for rapid screening of chemicals genotoxicity potential. A DNA probe from the clone RP3-402G11 gene of the human DNA sequence and electroactive methylene blue (MB) have been used as a biorecognition element and signal amplification molecules respectively for evaluating the genotoxic potential of target analytes with high sensitivity. The biosensing mechanism of genotoxicity screening is based on the damage of targets for the DNA double helix, which results in the subsequent distinct change of the electrochemical signal. More than 10 kinds of genotoxic chemicals have been used as testing analytes including highly toxic dioxins (polychlorinated dibenzodioxins, polychlorinated dibenzofurans) and polychlorinated biphenyls (PCBs). Dioxins and dioxin-like chemicals have been identified as highly genotoxic chemicals by the proposed DNA biosensor, which is consistent with the conclusion from International Agency for Research on Cancer. The results obtained demonstrated that the signal response of the biosensor for dioxins and PCBs correlated well with their toxic equivalent factor (TEF) values and concentrations of tested targets. The biosensor proved to be a promising in vitro screening tool for rapid estimation of chemicals genotoxicity potential.