THE DIRECT ELECTROCHEMISTRY OF HEMOGLOBIN AT BARE SILVER ELECTRODE AND APPLICATION IN ANALYSIS

This paper reports the electrochemical behaviour of hemoglobin at bare silver electrode. In the potential range of 0.4 similar to-0.2 V(vs. SCE), a pair of redox peaks was observed at +0.26 V(oxidation) and +0. 01 V(reduction) respectively at the sweep rate of 20 mV/s with an appa rent electron-transfer rate constant (K-s) 0.032 s(-1) and electron-tr ansfer number (n) 0.94. The redox reaction showed such a good stabilit y that the currents changed less than 0.2 mu A under a continued scan for 30 min. Hemoglobin was adsorped on the electrode surface, but it w as a faint adsorption. The electrode surface was not be stained during the redox reaction. In the medium of 0.1 mol/L NaAc-HAc(pH=4.5), both oxided current and reduced current are linear relationship with the c oncentration of hemoglobin in the ranges of 2X10(-7)similar to 2X10(-6 ) mol/L and 2X10(-6)similar to 1.5X10(-5) mol/L. It can be used as a m ethod for determining hemoglobin.