A comparison study between a disposable electrochemical DNA biosensor and a Vibrio fischeri-based luminescent sensor for the detection of toxicants in water samples.

In the present study, a comparison between a disposable electrochemical DNA biosensor and a Vibrio fischeri-based luminescent sensor for the detection of toxicants in water samples was made. In order to realize this study, a disposable electrochemical DNA biosensor has been reported. The DNA biosensor is assembled by immobilizing double stranded Calf Thymus DNA onto the surface of a disposable carbon screen-printed electrode. The oxidation signal of the guanine base, obtained by a square wave voltammetric scan, is used as analytical signal to detect the DNA damage; the presence of low molecular weight compounds with affinity for nucleic acids is measured by their effect on the guanine oxidation peak. Wastewater samples provided during First European Interlaboratory Exercise on water toxicity in the course of the project SWIFT-WFD were analyzed, and biosensor results were compared with a currently used toxicity test ToxAlert 100 based on the bioluminescence inhibition of Vibrio fischeri. This test have been used because is rapid, easy handling and cost effectively responses for the toxicity assessment in real water samples. The results showed a promising correlation between two tests used for the detection of toxic compounds in water samples.