A novel biosensor for simultaneous determination of two neurotransmitter Dopamine and serotonin in the presence of ascorbic acid using GCE/RGO/PPy/Pt NPs

Simultaneous determination of dopamine (DA) and serotonin (5-HT) is of greater value because of their coexistence in biological systems. These facts have encouraged chemists to developfaster, simpler, and more sensitive techniques and many works have been published describing the determination of DA and 5-HT concentrations using chemically modified electrodes [1]. Graphene has been used for the sensitive determination of various drugs molecules, due to theirexcellent conductivity because of π-π stacking and synergetic effects with other materials [2]. Polypyrrole has been considered as one of the most promising electrode materials to enhance the sensing sensitivity because of its low cost, easy synthesis, relatively high conductivity and goodelectrochemical/mechanical properties [3]. Platinium nanoparticles (PtNPs), due to their large aspect ratio (surface area to volume), biocompatibility, and high electerical conductivity have also been widely employed as a modifier in voltammetry analysis [4]. The morphology andstructure of the nanocomposite were characterized by the scaning electron microscopy (SEM),X-ray diffraction (XRD) and Fourier transform infrared (FT-IR). Among the bare (GCE) and GCE/RGO, GCE/RGO/PPy and GCE/RGO/PPy/Pt modified electrode namelyGCE/RGO/PPy/Pt exhibited much higher electrocatalytic activities toward oxidation of DA and 5-HT.The measurement were carried out in pH 7.0 PBS, by Cyclic voltammetry (CV) and Differential pulse voltammetry (DPV). The peak potential differences were 215 mV .The detection limits for DA, 5-HT both were 50 nM. The sensor showed excellent sensitivity, selectivity, and stability.

A novel biosensor for simultaneous determination of two neurotransmitter Dopamine and serotonin in the presence of ascorbic acid using GCE/RGO/PPy/Pt NPs Keywords:

Dopamine , Serotonin , Platinum nanoparticles , Polypyrrole , Graphene