Deoxyribonucleic acid (DNA) biosensors for environmental risk assessment and drug studies.

In the present work, electrochemical DNA biosensors are proposed as a screening device for the rapid bio-analysis of environmental pollution and DNA-drug interaction studies. The binding of small molecules to DNA immobilised on disposable screen-printed electrodes has been measured through the variation of the electrochemical signal of guanine by square wave voltammetric scans. These kinds of biosensors were used to evaluate the soil contamination level in an Italian polluted area and the results were compared with several methods for the DNA damage detection, as Comet genotoxicity effects, aberrant anatelophases and micronucleated cells frequency on plant roots, and with fixed wavelength fluorescence (FF) by using 2-aminoanthracene as standard compound. The results showed the ability of the biosensors to distinguish in 11 min low, medium and high contaminated soils with good correlation with well established techniques as well as FF, Comet and genotoxicity tests. The same kind of biosensors was also used to evaluate the interaction of DNA with some anti-proliferative metallo drugs, and the electrochemical responses reflected the kind of interaction. The reproducibility of the electrochemical measurements of DNA guanine peak was estimated as less than 10% of relative standard deviation (R.S.D.%).