PROPERTIES OF POLY-BETA-AMINOANTHRAQUINONE MODIFIED CARBON-FIBER ELECTRODE AS A BASIS FOR HEMOGLOBIN BIOSENSORS

An amperometric microsensor for hemoglobin (HE) has been constructed u sing a carbon fiber electrode modified with poly-beta-aminoanthraquino ne (pAAQ). Scanning electron microscopic studies showed that the poten tial range and time of electrochemical polymerization had strong effec ts on the morphology of the polymer film at the microelectrode. The st ability and the electrochemical properties of the modified electrode w ere studied using cyclic voltammetry. The pAAQ modified microelectrode showed an excellent electrocatalytic activity for the reduction of HE in a weakly acidic solution. The catalytic current in cyclic voltamme try increased linearly with the HE concentration between 1.0-400 mu M. The amperometric response to HE had a linear range of 0.5 mu M to 340 mu M with a correlation coefficient of 0.990(n=18). The biosensor was stable for at least one month when it was stored in a phosphate buffe r (pH 7.4) below 20 degrees C. The obtained HE concentration in the wh ole blood agreed well with the one obtained with the reference instrum ent.