Graphene nanoplatelet-based sensor for the detection of dopamine and N-acetyl-p-aminophenol in urine

This paper reports the development and application of a disposable sensor for the individual and simultaneous voltammetric determination of dopamine (DA) and N-acetyl-p-aminophenol (APAP). The sensor was fabricated by drop-coating graphene nanoplatelets (GNPs)-Nafion (Naf) nanocomposite onto the working area of a screen-printed electrode (SPE). The sensor, designated as GNPs-Naf/SPE, was characterized by scanning electron microscopy (SEM), Raman spectroscopy, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Differential pulse voltammetry (DPV) was used to simultaneously analyze DA and APAP in their binary mixtures. It showed excellent selectivity and sensitivity toward both compounds with limit of detection of 0.13 µM and 0.25 µM (S/N = 3) for DA and APAP, respectively. The performance of the sensor was evaluated by analyzing the compounds in human urine samples, and the recoveries were found to be well over 97.0%.