Carbonized Electrodes for Electrochemical Sensing

We have fabricated carbonized polymeric 3-D structures on silica substrate and carbonized them within CMOS operating temperature regime towards obtaining an integrated lab-on-CMOS electrochemical sensor. Metal layers of Ti and Au were deposited on silica substrate to provide electrical contact as well as expedite the formation of electrodes on the substrate. Polymeric conical structures were fabricated on metalized silica substrate using 3-D laser writing based on 2-photon polymerization. Desired carbonization of polymeric structures was obtained using a two step annealing process in oxidative and inert environments. Scanning electron microscopy was used to observe structure morphology and Raman spectroscopy verified carbonization. Finally, electrochemical and impedance characterization of the carbonized electrodes was carried out. Experimental results show the potential of these carbonized electrodes to be used in building low-cost and monolithic CMOS electrochemical sensors.