Um novo sensor eletroquímico baseado em materiais de baixo custo e altamente sensíveis para monitoramento de ácido úrico e epinefrina

A new and inexpensive electrochemical sensor was developed to simultaneous determination of epinephrine (EP) and uric acid (UA) based on gold nanoparticles modified graphite oxide paste electrode (AuNPs-GO/PE). Morphological characterization was performed by FEG-SEM (Figs. 1a and 1b), and the electrochemical behavior of the electrodes was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The combined used of AuNPs and graphite oxide (GO) enhanced the EP and UA voltammetric responses (Fig. 1c). By using differential pulse voltammetry (DPV), the obtained analytical curves (Fig. 1d) for EP and UA were linear of 1.2 × 10−6 to 1.4 × 10−5 mol L−1 , and detection limits of 1.0 × 10−7 (EP) and 2.4 × 10−7 mol L−1 (UA) were predicted, respectively. The AuNPs-GO/PE sensor showed good stability of response in intra- and inter-days repeatability studies, and good applicability for the analysis of synthetic biological samples samples (urine and serum)1,2. The proposed sensor is an alternative for the simple, inexpensive and very reliable simultaneous determination of EP and UA in different biological matrices samples.