Nonenzymatic glucose sensor design based on carbon fiber ultra-microelectrode: Controlled with a manual micro adjuster

Abstract

Interest in designing and manufacturing glucose sensors based on metal oxide-modified microelectrodes is growing and leading to the increased research efforts to develop continuous glucose measurements. A non-enzymatic glucose sensor based on an ultra-microelectrode is presented. A carbon fiber microelectrode electrodeposited by nickel nanoparticles (NiCFME) and activated as a nonenzymatic glucose sensor. The modified carbon microfiber was attached to a micro adjuster to adjust the height of the electrode inside the solution, which improved the accuracy of the microelectrode performance. The microstructure and morphology of the electrodes and nanoparticles investigated using SEM, EDX and XRD. The electrocatalytic glucose oxidation behavior of the sensing NiCFME got analyzed by cyclic voltammetry and amperometric measurements in alkaline medium. Achieved results demonstrated that the fabricated sensor displays the sensitivity up to 8.5 μA μM−1 cm−2 with a low detection limit of 3.0 μM, LOQ of 10.0 μM, with a linearity range of 10.0 μM–150.0 μM and response time about 0.4 s for glucose detection. Designed sensor had an appropriate good stability and significant selectivity towards glucose. Finally, the proposed sensor was successfully applied in determination of glucose in human blood plasma samples. The results illustrated; the proposed design is a promising candidate for the development of nonenzymatic glucose sensors.