Electrochemical determination of acetaminophen using a glassy carbon electrode modified with a hybrid material consisting of graphene aerogel and octadecylamine-functionalized carbon quantum dots

Abstract

The study reports on the synthesis of a graphene aerogel@octadecylamine-functionalized carbon quantum dots (GA@O-CQDs). The graphene oxide aqueous dispersion, O-CQDs aqueous dispersion and toluene were strongly mixed to make a toluene-in-water Pickering emulsion. The graphene oxide sheets in the aqueous phase are reduced by hydrazine hydrate, diffuse into the toluene droplets, and self-assemble into graphene oxide microgels. This is followed by freeze-drying and thermal annealing to obtain the GA@O-CQDs hybrid that has a three-dimensional structure of several microns. It was dispersed in ethanol and deposited on a glassy carbon electrode. The modified electrode was applied to differential pulse voltammetric determination of acetaminophen, best at a peak potential of 0.15 V (vs. Ag/AgCl). Figures of the merit include a wide linear response range (0.001-10 μM) and a 0.38 nM of the detection limit (S/N = 3). The assay has been applied to the determination of acetaminophen in tablets. Graphical abstract Schematic presentation of the synthesis of graphene aerogel@octadecylamine-functionalized carbon quantum dots. The synthesis achieves to the intimate chemical and electrical contact between graphene and carbon quantum dots. An electrode modified with the hybrid exhibits ultra high sensitivity for detection of acetaminophen.

Keywords: Detection; Differential pulse voltammetry; Schottky Barrier diode; Signal amplification; Tablets.