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 μM (R2 = 0.997). The detection limit was estimated to be 1.18 μM. 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 0.15 V and the other for acetaminophen at 0.39 V, 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.