A sensitive and selective platinum-based electrochemical sensor for detection of neurotransmitters: Design and proof of concept

Abstract

Monitoring the concentration of neurotransmitters in brain plays a vital role in the study and diagnosis of neurological diseases, but its sensitivity remains a challenge. In this study, a new electrochemical sensor was developed based on the modification of a glassy carbon electrode with graphene oxide and platinum microparticles (Pt/GO/GC) for simultaneous determination of epinephrine (EP), ascorbic acid (AA) and uric acid (UA). The morphology and structure of GO and Pt/GO/GC were characterized by FTIR spectroscopy, Raman spectroscopy, X-ray diffraction, scanning electron microscopy, EDS and cyclic voltammetry. Pt/GO/GC exhibits excellent catalytic activity for determining EP, AA and UA. Specifically, Pt/GO/GC separates the peak potentials for electro-oxidation of AA-EP by 190 mV and for EP-UA by 140 mV, while bare GC cannot resolve them. The simultaneous determination of these species in their mixture solution showed a wide linear response in the concentration ranges of 1–16 mM, 0.1–1.6 mM and 0.1–1.6 mM for AA, EP, and UA, respectively. In addition, the sensor was able to determine EP in the presence of different concentrations of AA and UA and it is feasible to be applied in the determination of EP in biological fluids.