C-MEMS Derived Glassy Carbon Electrodes as Sensitive Electrochemical Biosensors

Electrochemical biosensors have high potential for application in point of care setting, as they involve simpler measurements compared to optical counterparts and can operate in complex analyte. In this context, carbon electrodes have been widely explored since it is more stable than other metals. Pyrolyzed carbon electrodes have been deployed for protein sensing but the detection limit achieved is not satisfactory, probably due to the selection of the carbon precursor. In this paper, we have prepared glassy carbon electrodes using conventional carbon-microelectromechanical systems (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 in presence of 10 mM potassium ferricyanide solution. The samples have been immobilized with anti-Hep-B monoclonal antibody. 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 30% and 83% at the potential of 175mV for 1 fM and 1 pM concentrations respectively. Hence, the presented study is the proof-of concept of sensitive electrochemical detection of Hep-B using functionalized glassy carbon electrodes which when integrated with low cost microfluidic platform can become suitable for point-of-care diagnostics.