DNA-MODIFIED ELECTRODE FOR THE DETECTION OF AROMATIC-AMINES

A new electrochemical biosensing strategy has been developed for trace measurements of toxic aromatic amine compounds. The device relies on the intercalative collection of aromatic amines onto the immobilized d sDNA layer followed by potentiometric stripping quantitation of the ac cumulated species. The enhanced sensitivity, accrued from the DNA coll ection process, is coupled to new selectivity dimensions provided by t he structural requirements for such intercalative binding. The extent and rate of the accumulation are strongly dependent upon the structure of the aromatic amine species. Having the amino substituent in a slig htly different position produces a dramatic effect upon the response. Nanomolar detection limits are obtained after a 10-min accumulation, A pplicability to river water and groundwater samples is demonstrated. S uch DNA-based devices hold great promise for environmental screening o f toxic aromatic amines and for elucidating molecular interactions bet ween intercalating pollutants with DNA.