Highly Sensitive Bisphenol-A Electrochemical Aptasensor Based on Poly(Pyrrole-Nitrilotriacetic Acid)-Aptamer Film

An electrochemical highly sensitive aptasensor was developed based on electropolymerized poly(pyrrole-nitrilotriacetic) acid film and a new aptamer functionalized by a pentahistidine peptide for the quantification of bisphenol A. A surface coverage of antibisphenol A aptamer of 1.84 × 10–10 mol cm–2 was estimated from the electrochemical signal of the [RuIII(NH3)6]3+ complex bound by electrostatic interactions onto the aptamer-modified electrode. The binding of bisphenol A onto the polymer film was successfully characterized by electrochemical methods as square wave voltammetry and electrochemical impedance spectroscopy measurements. The designed label-free impedimetric aptasensor displayed a wide linear range from 10–11 to 10–6 mol L–1 with a sensitivity of 372 Ω per unit of log of concentration and an excellent specificity toward interfering agents such as 4,4′-dihydroxybiphenyl and bisphenol P.