Improved Carbonization Process of Nano-Electrodes for Biosensor Systems

This paper presents an improved process of partial to full carbonization of polymer nanoelectrode structures through thermal pyrolysis. A pillar and bridge structure of electrode array were developed using 3D laser writing based on 2-photon polymerization. Silicon, quartz, and glass ITO have been used as substrates. The two-step annealing duration time was varied from 10 hours to 30 minutes to achieve carbonized polymer structures by increasing input laser power of the 3D printing step. Two photoresist variants were used to build robust structures that can withstand the high temperature anneal. Carbonization of the structures were experimentally verified with Raman spectroscopy. Additionally, a biosensor system prototype was built by placing live biological cells on top of the carbonized nanoelectrodes and cell impedance measurement was conducted.