C-MEMS derived glassy carbon electrodes-based sensitive electrochemical biosensors

In this work, we have prepared glassy carbon electrodes using conventional carbon-microelectromechanical (C-MEMS) process. SU-8 photoresist has been used as the carbon precursor. The carbon thin film electrodes have then been tested by cyclic voltammetry measurements in the potential range of -800 mV to 800 mV vs Ag/AgCl electrode in presence of 10 mM potassium ferricyanide solution, without any functionalization. The samples have also been immobilized with anti-Hepatitis-B surface antigen (HBsAg) monoclonal antibody by physical adsorption. The presence of antibodies has been further confirmed by UV-VIS spectrophotometry. It has been observed that the current peak reduces distinctly and the fractional change in current magnitude is around 33% and 75% at the potential of 175 mV vs Ag/AgCl electrode for 10 fM and 100 fM concentration respectively. Hence, the presented study is the proof-of concept of electrochemical sensing behavior of HBsAg using functionalized glassy carbon electrodes which when integrated with low cost microfluidic platform can be suitable for point-of-care diagnostics.