Electrochemical Behavior of Uric Acid at the Polysulfosalicylic Acid Modified Glassy Carbon Electrode and Its Analytical Application

The pretreated glassy carbon electrode (GCE) was modified with polysulfosalicylic acid (PSSA) by electropolymerization with cyclic voltammetry and the modified electrode,PSSA/GCE,was studied for its electrochemical behavior toward uric acid.In a phosphate buffer solution of pH 5.59,a sensitive oxidation peak given by uric acid was observed at the potential of 0.458 V (vs.SCE).A method for determination of uric acid was proposed by using the differential pulse voltammetry.Linear relationship between values of peak current of the oxidative peak and concentration of uric acid was obtained in the range from 1.0×10-7 to 8.0×10-6mol·L-1.Detection limit (3S/N) of 2.0×10-8mol·L-1 was obtained when enriched for 60 s with stirring under open circuit.