Modification of electrode using arrowroot starch membrane for uric acid determination

Abstract

Arrowroot starch membrane-modified glassy carbon electrode were constructed for the determination of uric acid. The membrane consist of arrowroot starch, polyvinyl alcohol, uric acid, and crosslinker. The crosslinker used was sodium tripolyphosphate, citric acid, and glutaraldehyde. Dry membrane was mixed with carbon to increase the sensitivity. Carbon is conductive and hydrophobic material. Therefore, carbon can increase conductivity of modified electrode. Modified electrode was used to analyse uric acid concentration in acetate buffer pH 5 and 0.2 M KCl using differential pulse voltammetry. The potential applied was 0-1.0 V at scan rate of 2.5 mV/s, amplitude modulation was 300 V, and time modulation was 10 ms. The composition of membrane influences the electrodes sensitivity. The best composition of arrowroot starch membrane is UA1 using 0.1% uric acid in membrane and STPP as crosslinker. The linearity concentration, sensitivity, and limit of detection were 100-500 µM, 0.0509 A/M and 76 µM, respectively.