determination of acetaminophen and dopamine in the presence of ascorbic acid using the silver nanoparticles/mwcnts -modified carbon paste electrode

Abstract: in this work, a carbon-paste electrode (cpe) is modified by incorporating silver nanoparticles/mwcnts composite. the resulted modified electrode is used as a sensitive voltammetric sensor for simultaneous determination acetaminophen (ac) and dopamine (da). the electrode showed efficient electrocatalytic activity in lowering the anodic overpotentials and enhancement of the anodic currents. this electrode is able to completely resolve the voltammetric responses of ac and da. the effects of potential sweep rate and ph of the buffer solution on the response of the electrode, toward ac and da, and the peak resolution is thoroughly investigated by cyclic and differential pulse voltammetry (cv and dpv). the best peak resolution for these compounds using the modified electrode is obtained in solutions with ph 4.0. peak potential separation is resulted for two compounds. the modified electrode showed good sensitivity and selectivity to the electrode has very good reproducibility (r.s.d.≤3%), low detection limits for ac and da was 0.1 and 0.6 micromolar respectively. the prepared electrode is successfully applied for the voltammetric detection of ac and da in pharmaceutical preparations.