Determination of Adenine and Guanine by a Dopamine-Melanin Nanosphere-Polyaniline Nanocomposite Modified Glassy Carbon Electrode

A novel electrochemical sensor has been developed for guanine and adenine determination based on a dopamine-melanin nanosphere/polyaniline nanocomposite. The nanocomposite was characterized by scanning electron microscopy, transmission electron microscopy, and infrared spectroscopy. The oxidations of guanine and adenine were studied by cyclic voltammetry and differential pulse voltammetry. The modified electrode exhibited favorable electrocatalytic activity and stability for the simultaneous determination of guanine and adenine. The sensor showed long linear dynamic ranges from 0.05 to 100 mu M with limits of detection of 0.01 mu M and 0.008 mu M for guanine and adenine, respectively. The fabricated electrode was used to determine guanine and adenine in denatured DNA, demonstrating its potential application as an electrochemical sensor.