| In this research, an interdigitated array (IDA) nanoelectrode with a dynamic transduction mechanism and its interface ASIC has been proposed, developed and characterized. This research is aiming to develop an extremely high sensitive electrochemical IDA nanosensor with a simple instrumentation in the determination of reversible redox species.; The key approach of the dynamic transduction mechanism, which has been explored through this work, is a charge injection method, where a charged capacitor is used as the charge supplier for the electrochemical reaction of the reversible redox species at the interdigitated array electrodes, and the characteristics of the capacitor (or electrode) potential decay are recorded and analyzed to evaluate the concentration of reversible redox species.; The modeling of the planar IDA nanoelectrode using charge injection method has been driven from the fundamentals of electrochemistry to predict the sensor performance and illustrate the calibration method. A small surface-area IDA nanoelectrode with a finger width of 100 nm and a finger spacing of 200 nm has been fabricated using e-beam lithography for experiments after nano lift-off and the mixed-matched nano/micro lithography process were investigated in this research. The IDA nanoelectrode has achieved the detection limit of around 6 x 10-9 M for the reversible redox species.; Interface application-specific-integrated-circuit (ASIC) for IDA nanoelectrode has been designed, fabricated and fully characterized. The interface ASIC converts the sensing analog signal to the digital signal, and provides a communication capability for microcontroller/microprocessor/DSP.; In summary, an electrochemical nano sensor using a dynamic electrochemical transduction mechanism, as well as its interface ASIC, has been proposed, implemented and successfully characterized in this thesis. Experimental results have shown that the IDA nanoelectrode using the charge injection method has a high potential as a new electrochemical nanocell for the detection of a single biochemical molecule, including DNAs, proteins or enzymes. Furthermore, the new electrochemical nanocell and the detection method can be easily integrated with the micro/nano analytical devices or systems for the trace determination with a low cost hand-held instrumentation or analyzer. |
