Non-enzymatic Determination of Uric Acid by Ion Exchange Voltammetry at a Permselective Electrochemical Sensing Platform

Abstract

Here we demonstrate a new strategy for electrochemical determination of uric acid (UA) using a cationic polymer as an electrochemical sensing platform (ESP). The cationic polymer is based on branched polyethylenimine (BPEI) cross-linked with ethylene glycol diglycidyl ether (EGDE). Ion exchange property of this cross linked cationic polymer (BPEI-EGDE) with negatively charged electroactive species is studied by cyclic voltammetry. Furthermore, this cationic cross-linked BPEI-EGDE polymer is coated on a glassy carbon electrode (GC) to construct the ESP for the quantitative analysis of biologically important molecule, UA at pH 7.0. It shows efficient oxidation of UA with respect to bare GC due to favorable electrostatic interaction of anionic UA with the positively charged BPEI-EGDE film. Finally it is demonstrated that the BPEI- EGDE films can be used as efficient ESP for non-enzymatic UA determination in the concentration range of 5 to 1500 µM with a sensitivity of 153 µA μM-1cm-2.