Electrochemical biosensor platform based on electron tunneling

Abstract

We propose an electrochemical protease biosensor platform, called T-chip based on electron tunneling (electrochemistry) and the voltage pulse method to extract the pure transient tunneling current characteristics of the sensor device. By analyzing the I-V and C-V characteristics of the T-chip device with its unique structure having the 2-terminal asymmetric electrodes, the new perspective on the T-chip device describing as the metal-insulator-electrolyte (MIE) capacitor has been suggested.<br/> <br/> The biosensor application for the detection of the Trypsin as the target molecule has been demonstrated in the imitated human serum condition with the high concentration of the nonspecific BSA protein of 500 µM. It has been found that the voltage pulse method can enhance the sensitivity and the nonspecific-to-specific ratio performances of the biosensor device than the cyclic-voltammetry measurement. <br/> <br/> In addition, the effect of the back-filling materials on the surface of the electrodes has been studied, and the optimized structure of the T-chip device has been established. The biomolecular transport in the bulk electrolyte solution and the biochemical reaction has been simulated by solving the reaction-diffusion equation and Menten-Michaelis kinetics. The equivalent circuit of the T-chip device is also proposed, and simulated by using the MNA technique. To overcome the limitation of the voltage pulse method, the generalized voltage pulse method based on the integration of the tunneling current is suggested. Finally, the pH sensor application of the T-chip device has been demonstrated by utilizing the MCH-SAM on the electrode of the device. <br/> <br/> In this research, we have focused on creating new perspectives even there are somewhat rough and radical assumptions. Even if our approach is not that much perfect and the experimental data are not that much precise, we believe that it is of great value to find new possibilities for the future device not only in the biosensor industry but also in the other scientific field developing the solid-state devices.<br/>