應用於生物感測器之可攜式多通道恆電位儀設計

Design of a Portable Multi-Channel Potentiostat for Biomolecule Sensors

本論文提出一個可攜式多通道恆電位儀之設計，作為電化學生物感測器之信號處理裝置，本文所設計之恆電位儀對於電化學實驗中常應用的三種量測方法：電位法、伏安法與循環伏安法均可實現。在恆電位儀的系統驗證方面，我們把葡萄糖感測器、兒茶素感測器、及咖啡因感測器與多通道恆電位儀整合在一起，並應用於茶飲料的成分測試，在與商用恆電位儀之測試結果做比較時，實驗結果顯示在加入不同濃度的待測物時，我們的系統對於感測器上所量測到的電流變化，與商用恆電位儀的反應有相同的趨勢。從實際樣品的測試結果，透過檢量線檢測三種市售茶飲中所含有咖啡因及兒茶素濃度分別為0.103~0.142mg/mL及0.40–1.74mg/mL。此外，所提出的多通道恆電位儀，具有體積小、重量輕、方便攜帶、製作成本低、及可同時量測多組感測器等特點，在未來與電化學生物感測器整合，將可實現居家型照護系統。

In this paper, we propose a portable multi-channel potentiostat for the signal processing of electrochemical biosensors. The proposed potentiostat can perform three operation modes which are commonly used in electrochemical experiments: potentiometry, voltammetry, and cyclic voltammetry. In system verification, taking advantage of the function of cyclic voltammetry, we integrate the proposed potentiostat with a glucose sensor, an epigallocatechin gallate (EGCG) sensor and a caffeine sensor to measure glucose, EGCG and caffeine concentrations in green tea. The experimental results show that the biosensor currents measured by the proposed potentiostat have the same trend as those measured by the commercial one when glucose, EGCG and caffeine concentrations change. According to the calibration curve, the measured concentrations of caffeine and EGCG in three green tea samples are 0.103~0.142 mg/mL and 0.40–1.74 mg/mL, respectively. Besides, the proposed multi-channel potentiostat has the merits of small size, light weight, high portability, low cost, and being able to measure multi-biosensors at the same time. In the future, we will integrate the proposed potentiostat with biosensors to develop the home-care system in daily life.