Electrochemical DNA nano-biosensor for the detection of genotoxins in water samples

In the present study, a disposable electrochemical DNA nano-biosensor is proposed for the rapid detection of genotoxic compounds and bio-analysis of water pollution. The DNA nano-biosensor is prepared by immobilizing DNA on Au nanoparticles and a self-assembled monolayer of cysteamine modified Au electrode. The assembly processes of cysteamine, Au nanoparticles and DNA were characterized by cyclic voltammetry (CV). The Au nanoparticles enhanced DNA immobilization resulting in an increased guanine signal. The interaction of the analyte with the immobilized DNA was measured through the variation of the electrochemical signal of guanine by square wave voltammetry (SWV). The biosensor was able to detect the known genotoxic compounds: 2-anthramine, acridine orange and 2-naphthylamine with detection limits of 2, 3 and 50 nmol/L, respectively. The biosensor was also used to test actual water samples to evaluate the contamination level. Additionally, the comparison of results from the classical genotoxicity bioassay has confirmed the applicability of the method for real samples.

An electrochemical DNA nano-biosensor is proposed for the rapid detection of genotoxic compounds and bio-analysis of water pollution. The DNA nano-biosensor was prepared by immobilizing DNA on the Au electrode modified with Au nanoparticles and a self-assembled monolayer of cysteamine.Figure optionsDownload as PowerPoint slide