Determination of acetaminophen by electrochemical co-deposition of glutamic acid and gold nanoparticles

We developed an electrochemical sensor to detect acetaminophen by electrochemically co-depositing glutamic acid and gold nanoparticles on a single-walled carbon nanotube film (AuNP-PGA/SWCNT). Cyclic voltammetry indicated that the electrochemical oxidation of acetaminophen at the AuNP-PGA/SWCNT film electrode involved a two-electron, one-proton process and was pH dependent. Different pulse voltammograms of acetaminophen oxidation on the AuNP-PGA/SWCNT film electrode yielded a well-defined oxidation peak at 360 mV in 0.1 M phosphate buffered saline buffer (pH 7.2) with linear calibration from 8.3 to 145.6 mu M (R-2=0.997). The detection limit was estimated to be 1.18 mu M. The proposed sensor is stable and reproducible from 1.15 to 5.21% with a relative standard deviation of 3.56%. The AuNP-PGA/SWCNT film electrode was able to detect acetaminophen in the presence of interfering ascorbic acid; two well-defined oxidation peaks, one for ascorbic acid at 0.15V and the other for acetaminophen at 0.39V, were detected. Furthermore, the fabricated sensor accurately measured the amount of acetaminophen in pharmaceutical samples. Together, these results indicate that our AuNP-PGA/SWCNT film is a promising platform for accurate and reproducible detection of acetaminophen. (C) 2012 Elsevier B.V. All rights reserved.