Electrocatalytic resolution of guanine, adenine and cytosine along with uric acid on poly (4-amino-3-hydroxy naphthalene-l-sulfonic acid) modified glassy carbon electrode

A simple, easy to fabricate, selective and sensitive sensor for simultaneous determination of nucleic acid bases guanine, adenine and cytosine along with uric acid is being reported in this article. Glassy carbon electrode with an electropolymerised layer of 4-amino-3-hydroxy naphthalene -1 -sulfonic acid could resolve the oxidation peaks of uric acid, guanine, adenine and cytosine using 0.1 M NaOH as supporting electrolyte. The electrocatalytic oxidation current was found to be linear in the range from 10 mu M-250 mu M for uric acid, guanine and adenine and 80 pM-250 pM for cytosine with detection limit 9.31 mu M, 0.93 mu M, 6.20 mu M and 9.20 mu M respectively for simultaneous determination by square wave voltammetry. The diffusion coefficient of uric acid, guanine, adenine and cytosine in 0.1 M NaOH has been determined by chronoamperometry. The electrode processes were found to be diffusion controlled, which eliminate the fouling effect produced by adsorption of these organic compounds on the electrode surface. The developed sensor has been demonstrated to have promising applications for real sample analysis.