Detection of acetaminophen in the presence of ascorbic acid using the modified electrode with Multi-Walled CarbonNanotubes/Mo(VI) complex

A composition of multi-walled carbon nanotube (MWCNT) and Mo(VI) complex is applied for themodification of carbon-paste electrode (CPE). The pretreated MWCNT is well dispersed in the alcoholicsolution of Nafion under the ultrasonic agitation, and the resulted suspension is used as modifier (with ۱۰W/W%) in the matrix of the paste electrode. The prepared electrode further modified by addition of ۳wt% ofMo(VI) complex. The resulted modified electrode is used as a sensitive voltammetric sensor fordetermination of acetaminophen (AC) in the presence of ascorbic acid (AA). The electrode showed efficientelectrocatalytic activity in lowering the anodic overpotentials and enhancement of the anodic currents. Thiselectrode showed to be able to completely resolve the voltammetric response of AC and AA. The effects ofpotential sweep rate and pH of the buffer solution on the response of the electrode, toward AC and AA, andthe 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 =۴. The ΔEp for AC and AA in these methods is resulted as about ۳۱۵ mV, which is considerably better thanprevious reports for these compounds. A linear dynamic range of ۱×۱۰-۷ to ۱×۱۰-۴ M with a detection limit of۶×۱۰-۸ M is resulted for AC in buffered solutions with pH ۴.۰. The voltammetric detection system was verystable and the reproducibility of the electrode response, based on the six measurements during one month,was less than ۳.۵% for the slope of the calibration curves of AC. The prepared modified electrode issuccessfully applied for the determination of AA and AC in mixture samples and reasonable accuracies areresulted.

کلیدواژه ها:

Modified electrode ، Carbon nanotube ، Mo(VI) complex ، Acetaminophen