Reduced Graphene Oxide Screen-Printed FTO as Highly Sensitive Electrodes for Simultaneous Determination of Dopamine and Uric Acid

A novel electrochemical sensor was fabricated by simply screen printing reduced graphene oxide (rGO) paste on F-doped tin oxide (FTO) (rGO-SP-FTO) followed by sintering at 450 degrees C in Argon and employed for detecting dopamine (DA) and uric acid (UA) simultaneously. The rGO film was characterized by using Raman spectroscopy, field emission scanning electron microscope (FE-SEM), and Fourier transform infrared spectroscopy (FTIR). The surface sensing features of rGO-SP-FTO were studied with electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The rGO-SP-FTO electrode exhibited foremost sensitivity in simultaneous detection of DA and UA without any interference from ascorbic acid (AA). The rGO-SP-FTO electrode showed a good linear response in the range of 0.5-50.0 mu M and 5.0-300 mu M with detection limits (S/N = 3) of 0.07 mu M and 0.39 mu M for DA and UA, respectively. The interactions between screen printed rGO with FTO electrode and their influence on how rGO-SP-FTO electrode interacted with UA, DA, and AA were analyzed from experimental observations. The rGO-SP-FTO electrode was able to detect DA in dopamine hydrochloride injection (DAI) and UA in urine sample effectively. Moreover, the designed electrochemical sensor exhibited excellent stability and reproducibility. (C) 2018 The Electrochemical Society.