Eletrodos impressos à base de compósitos carbono/óxido de grafeno eletroquimicamente reduzido/negro de fumo para a detecção de fármacos e neurotransmissores

Carbon black (CB) is the term used to define a carbon-containing material produced from combustion, or thermal decomposition, of different oil products. This material has been a focus of great interest for the development of electrochemical sensors [1] mainly due to its relatively low cost and interesting properties such as high specific surface area, electric conductivity, and chemical stability [2]. Here, we explore the use for analytical applications of a composite material based on CB and electrochemically reduced graphene oxide (ERGO) as an electrode modifier. Homemade screen printed carbon electrodes (SPCE) were prepared and modified with a graphene oxide-CB dispersion following by electrochemical reduction. The electrodes were characterized by using scanning electron microscopy and contact angle measurements. The voltammetric responses of the electrodes (SPCE/ERGO-CB) were investigated at different concentrations by cyclic voltammetry in paracetamol (PCM) and dopamine (DA). Both probes exhibited a significantly improved performance when compared with bare (SPCE), and modified (SPCE/CB and SPCE/ERGOX) electrodes. The analytical curves were obtained for both analytes by square wave voltammetry, for which excellent analytical responses were obtained, including high response stability, low detection limit (DA: 7.23 × 10−7 mol L −1 and PCM: 8.52 × 10−7 mol L−1 ) and a high sensitivity (DA: 1.49 A L mol−1 and PCM: 0.0201 A L mol−1 ). These results demonstrate that ERGO-CB has a potential relevance as an electrode modifier for sensor applications.