以二氧化錫薄膜為基礎進行電壓式乳酸生物感測器研製及應用

Study and Application of a Potentiometric Lactate Biosensor Based on a SnO2 Thin Film

林志晟(Zhi-Cheng Lin)

指導教授 ： 熊慎幹 ； 高慧玲

中原大學/工學院/電子工程研究所/碩士(2008年)

https://doi.org/10.6840/cycu200900422

摘要

乳酸係人體新陳代謝之重要參數，且於臨床量測方面亦為判斷病患生理狀況之重要指標。此外，乳製品製作過程中藉由發酵反應生成乳酸，故乳酸濃度亦係判斷食品新鮮程度之重要參數。故備製具有偵測乳酸濃度之乳酸生物感測器具重要應用性。
本論文係分別藉由固態式二氧化錫/氧化銦錫與二氧化錫/碳電極為基礎，並結合酵素固定化技術製作酵素感測膜，研製固態式乳酸生物感測器。此生物感測器係可於水溶液中量測乳酸之濃度，此外本研究亦針對電壓式乳酸生物感測器之架構進行探討，並提升元件之感測特性。此電壓式乳酸生物感測器之基礎原理係溶液中乳酸分子藉由乳酸脫氫酵素與輔酵素煙醯胺腺嘌呤二核苷酸催化產生丙硐酸與氫離子，乳酸反應後所釋放之氫離子造成感測元件表面酸鹼值改變並由二氧化錫薄膜為基礎之酸鹼感測器進行偵測。
依據研究結果，可得知以二氧化錫/氧化銦錫電極為基礎製作之乳酸生物感測器於線性量測範圍(5mM~50mM)之感測度約為61.3mV/decade，反應時間約為10至15秒，最小乳酸濃度量測極限約為3.6mM。以二氧化錫/碳電極為基礎製作之乳酸生物感測器於線性量測範圍(5mM~50mM)之感測度約為59.8mV/decade，反應時間約為10秒鐘，最小乳酸濃度量測極限約為4.5mM。由研究結果可得知以二氧化錫/氧化銦錫電極及二氧化錫/碳電極為基礎製作之電壓式乳酸生物感測器，其皆具備製程簡單、製作成本低及可進行微小化之優點。
於本研究中，以二氧化錫薄膜為基礎研製之電壓式乳酸生物感測器具備製程簡易、特性良好、可進行量產等優點，期望未來可普遍應用於居家乳製品新鮮度之檢測。

關鍵字

乳製品 ； 新鮮度檢測 ； 酵素固定 ； 二氧化錫/氧化銦錫結構 ； 電壓式乳酸生物感測器

並列摘要

Lactic acid is an important parameter for human body, and detection of lactic acid is great interests in clinical analysis and application. In addition, lactic acid is an important parameter to apply for freshness intensity of the dairy product by lactate measurement. Hence, the device that developed for detect the lactate was called lactate biosensor.
This study investigates a solid state lactate biosensor based on a tin oxide (SnO2)/indium tin oxide (ITO) electrode and tin oxide/carbon electrode with an enzyme immobilization process. The lactate biosensor detects lactate concentration in solution. Moreover, the lactate dehydrogenase (LDH) and coenzyme (nicotinamide adenine dinucleotide, NAD+) are co-immobilized on the pH sensitive membrane by 3-glycidoxypropyltrimethoxysilane (GPTS). After the reactions of enzyme, the resulting product, H+, was detected by the SnO2 thin film.
According to the experimental results, sensitivity of the potentiometric lactate biosensor based on the SnO2/ITO glass electrode was about 61.3 mV/decade in the linear range between 5 mM to 50 mM lactate concentration, and response time (t95%) of the lactate biosensor was about 10 seconds. Besides, detection limit of the lactate biosensor based on the SnO2/ITO glass electrode was 3.6mM. Moreover, sensitivity of the lactate biosensor based on the SnO2/carbon electrode was about 58.9 mV/decade in the linear range between 5 mM to 50 mM lactate concentration, and response time (t95%) of the lactate biosensor based on the SnO2/carbon electrode was about 10 seconds. Besides, the detection limit of lactate biosensor based on the SnO2/ carbon electrode was 4.5mM.
In this study, potentiometric lactate biosensors based on the SnO2 thin film has some advantages such as easy fabrication process, good quality, capable for mass production. Furthermore, the lactate biosensor is applicable for measuring the lactate concentration of dairy sample for freshness detection in the future.

並列關鍵字

dairy ； enzyme immobilization ； SnO2/ITO structure ； Potentiometric lactate biosensor ； freshness detection.

參考文獻

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