▎ 摘　　要

A novel electrochemical sensor for sensitive detection of methyldopa at physiological pH was developed by the bulk modification of carbon paste electrode (CPE) with graphene oxide nanosheets and 3-(4-amino-3-hydroxy-biphenyl-4-yl)-acrylic acid (3,AA). Applying square wave voltammetry (SWV), in phosphate buffer solution (PBS) of pH7.0, the oxidation current increased linearly with two concentration intervals of methyldopa, one is 1.0x10(-8)-1.0x10(-6)M and the other is 1.0x10(-6)-4.5x10(-5)M. The detection limit (3 sigma) obtained by SWV was 9.0nM. The modified electrode was successfully applied for simultaneous determination of methyldopa and hydrochlorothiazide. Finally, the proposed method was applied to the determination of methyldopa and hydrochlorothiazide in some real samples.