Biossensor de glicose reutilizável baseado em glicose oxidase e concanavalina a imobilizadas em composto de polianilina e óxido de grafeno reduzido montado em eletrodo de cobre

Abstract

According to the World Health Organization (WHO), in 2014 there were about 442 million people with diabetes in the world, of which an estimated 7.4 % were Brazilian. In Brazil, the cost of diabetes-related hospitalizations was $ 270 million in 2014. About 1.6 million deaths were directly attributed to diabetes in 2016, and it is estimated that by 2035 there will be 592 million diabetics worldwide. Such a disease can lead to serious complications in the cardiovascular system, blood vessels, eyes, kidneys and nerves. Therefore, the development of personal glycemic level monitoring devices that operate reliably at low cost is of utmost importance. In this study, a glucose biosensor was developed from the immobilization of glucose oxidase (GOX) and concanavalin A (ConA) in a polyaniline (PANI) and reduced graphene oxide (rGO) blend deposited in a lowcost simple fabrication cooper electrode. The proteins were immobilized by glutaraldehyde crosslinking. Copper electrodes were made by the thermal transfer method on a copper/phenolite plate. Three variations of the device were developed, called Cu-PANIG/rGO-GOX, Cu-PANIG/rGO-GOX-ConA and PET/ITO-PANIG/rGO-GOX. The PANI-rGO mixture was characterized by UV-vis spectroscopy and cyclic voltammetry. Biosensors were characterized in the presence of H2O2 and D-glucose by cyclic voltammetry and chronoamperometry. The devices presented linear behavior from 31 to 217 mg/dL. Sensitivity values were 36.30 μA/mM∙cm² for Cu-PANIG/rGO-GOX, 20.87 μA/mM∙cm² for CuPANIG/rGO-GOX-ConA, and 9.90 μA/mM∙cm² for PET/ITO-PANIG/rGO-GOX.