EXFOLIATED GRAPHITE APPLICATION IN PASTES FOR SCREEN PRINTED ELECTROCHEMICAL SENSORS

Abstract

This paper presents the graphite-based paste, within which an exfoliated graphite as the main electrically conductive component was selected. The resulting graphite-based paste is a homogenous polyvinyl chloride mixture containing carbon materials with different particle sizes (such as gas soot and microcrystalline graphite). The preparation of electrical conductivity graphite-based paste and electrode sample based on it and obtained by means of screen printing technology. The purpose of electrode properties exploration is to elucidate its applicability as a main component of electrochemistry biosensor for glucose concentration measurements in blood. The results of a comparative analysis of printed electrodes based on it with electrodes made of commercial graphite paste from one of the world's leading manufacturers (Gwent Electronic Materials) are presented. The obtained electrodes were characterized by comparable physical and electrochemical parameters. According to the results of scanning electron microscopy of electrodes, graphite paste with exfoliated graphite is suitable for screen printing. The electrical resistivity of the electrodes with exfoliated graphite was 440 (Ohms·mm2)/m, and the electrodes obtained on the basis of commercial paste – 270 (Ohms·mm2)/m. The biosensor, made on the basis of the original graphite paste, is characterized by a wide range of linearity of response to glucose in the range from 1 to 40 mM, and similar values of currents and sensitivity compared to a commercial analogue. The results of studies of the obtained electrodes have shown that exfoliated graphite is a promising material for use in electrochemical systems, and reducing the concentration of carbon conductive components can significantly reduce the cost of finished graphite paste and increase its commercial potential.