DESENVOLVIMENTO DE SENSOR ELETROQUÍMICO A BASE DE PLATINA - ÓXIDO DE GRAFITE PARA DETERMINAÇÃO DE ADRENALINA NA PRESENÇA DE ÁCIDO ASCÓRBICO E ÁCIDO ÚRICO

Abstract

Adrenaline (Adr) is a neurotransmitter that plays an important role during moments of physical and mental stress and changes in its concentration in biological fluids is related to human pathologies such as neurological disorders like as Parkinson's disease, Alzheimer's, schizophrenia and hyperactivity. Timely and accurate determination of Adr concentrations in the presence of its biological interferents, such as ascorbic acid (AA) and uric acid (UA), is critical for effective diagnosis, disease monitoring, therapeutic interventions, and evaluation of new drugs in many areas from diseases such as diabetes, heart disease, anxiety and other neurological disorders. Thus, the present work describes the development of an electrochemical sensor based on the modification of a

glassy carbon electrode with graphene oxide and platinum microparticles Pt/OG/CV for simultaneous determination of AA, Adr and UA. The morphology and structure of the OG were characterized by infrared spectroscopy with Fourier transform, Raman spectroscopy, X-ray diffraction, scanning electron microscopy, X-ray spectroscopy by energy dispersion and cyclic voltammetry. The Pt/OG/CV sensor was characterized by scanning electron microscopy, mapping by Energy dispersive X-ray spectroscopy and cyclic voltammetry. The Pt/OG/CV sensor exhibited excellent catalytic activity for determining AA, Adr and UA. The Pt/OG/CV sensor separated the peak potentials for electrooxidation of AAAdr at 190mV and for Adr-UA at 140mV, while the bare glassy carbon electrode cannot resolve them. Simultaneous determination of these species in their mixture solution showed a wide linear response of 1–16 mM, 0.1–1.6 mM and 0.1–1.6 mM for AA, Adr, and UA, respectively. In addition, the sensor was able to determine Adr in the presence of different concentrations of AA and UA. The sensor presented Limit of Detection and Quantification of 0.68 and 2.06 µMol L -1 respectively, with repeatability and reproducibility within the standards established by ANVISA.