dc.description.abstract | This thesis introduces our development of a portable electrochemical measurement device and its applications. In recent years, the portable potentiostat has become a popular device used in electrochemical measurement. Conventional electrochemical workstations such as IM6ex (ZAHNER-elektrik GmbH & Co. KG, Germany) are expensive, bulky, and need professional operators. On the contrary, our device is portable, inexpensive, and easy to use. The core of the portable impedance measurement device is a 16-bit microprocessor ATxmega32A4 from Atmel. The microprocessor facilitates signal amplification and potential controlling by incorporating the operational amplifier TLC2264ID. The function of the microprocessor is programmed in C language in the integrated development environment provided by Atmel AVR Studio. Weighting 120 g, the portable impedance measurement device provides four measurement modes: square wave voltammetry (SWV), cyclic voltammetry (CV), Chronoamperometry (CA), and linear sweep voltammetry (LSV). The measurement range of the portable device is ±990 mV and 050 μA. Its accuracy was evaluated by comparing its measurement results with those measured with IM6ex as well as the theoretical values. The experiment results showed that the difference is within 2%. We further utilized our portable measurement device to detect creatinine and human serum albumin (HSA) with the screen-printed porous carbon electrode (SPPCE). Creatinine and HSA are important diagnostic indicators of chronic kidney disease (CKD). Different concentrations of creatinine and HSA in patients who suffer from CKD may refer to different levels of CKD. To catalyze creatinine into a redox reaction, we immobilized creatininase (EC 3.5.2.10), creatinase (EC 3.5.3.3), and sarcosine oxidase (EC 1.5.3.1) on the SPPCE to detect the electrochemical signal of creatinine. The creatinine detection results showed a high correlation coefficient (R2 = 0.99) in the calibration line. As for HSA detection, we immobilized anti-HSA on SPPCE to capture HSA by means of the specific adsorption between antibody and antigen. The HSA detection result also showed a high correlation coefficient (R2 = 0.997). | en_US |