加熱式膽固醇感測電極─訊號增益與干擾物探討

Heating based cholesterol sensing electrode - studies of signal enhancement and interference exclusion

劉孋鋆(Li-Yun Liu)

指導教授 ： 婁世亮

中原大學/工學院/生物醫學工程研究所/碩士(2015年)

https://doi.org/10.6840/CYCU.2015.00145

摘要

本研究主要目的為研發加熱式膽固醇感測電極，以增強膽固醇訊號並排除干擾物質影響。加熱來源為聚亞醯氨製成之加熱電熱片。運用電源供應器施加加熱電熱片4 V電壓，使電極表面升溫至41.2 ℃，藉此加速膽固醇擴散速率，增強反應訊號。首先將白金電極(Pt)與加熱電熱片組合成加熱式電極。游離膽固醇電極製備中使用普魯士藍(PB)聚合電極表面，再沈積白金奈米粒子(nano Pt)，藉此增強膽固醇量測訊號，完成後滴覆由膽固醇氧化酶(ChOx)與牛血清蛋白(BSA)共同交聯之酵素液，最後於電極外層覆蓋上硫醇基丙基三甲氧基矽烷(MPTMS)，用以固定酵素及阻擋干擾物質穿透，將游離膽固醇電極製備條件應用於加熱式電極即完成本研究加熱式膽固醇感測電極製備。電極於加熱情形下偵測膽固醇反應訊號，其濃度線性範圍為1~10 mM，線性相關係數R值為0.973。將電極置於膽固醇溶液中進行重覆量測20次，感測訊號並未影響，顯示本研究之電極具有良好再現性。將本實驗加熱式膽固醇感測電極保存於磷酸緩衝溶液4℃中，並進行每日量測膽固醇溶液，反應訊號隨著天數增加而降低，半衰期為第7天。
由實驗結果證實，本研究成功製備加熱式膽固醇感測電極，且具有增強反應訊號以利降低干擾物質影響之作用。

關鍵字

加熱式電極 ； 膽固醇感測器 ； 奈米白金粒子 ； 普魯士藍 ； 膽固醇氧化酶

並列摘要

The goal of this study is to develop an electrochemistry electrode that is capable of enhancing cholesterol (ChO) signals and yet eliminating signals from interferences including ascorbic acid (AA), uric acid (UA) and acetaminophen (AP). The substrate of the electrode used in this study is a 3x3 mm2 platinum (Pt) foil. It was assembled with a heating pad having the same size of the Pt substrate. A layer of Prussian blue was first modified on the Pt substrate followed by a layer of Pt nanoparticle deposition. A cross-linking reagent consisting of cholesterol oxidase (ChOx) and bovine serum albumin was then modified on top of the deposition layer. Finally, the electrode was completed by fully covering an outer shell of (3-mercaptoppropyl)-trimethoxysilane. The heating pad was able to increase the temperature of the electrode surface from room temperature to 41.2 ℃ by applying an voltage of 4 V. With an operation voltage of 0.4 V, the dynamic detecting range of the electrode was from 1 to 10 mM (n=20, the linear correlation coefficient R is 0.972). The signal enhancement by the 4-V thermal effect is about 5 folds comparing to that of the non-heating. The interference reduction was also significant. With the 4-V thermal effect, the performance of the electrode in terms of the noise to signal ratios was 7.43, 0.00 and 8.48 % for AA/ChO, AP/ChO and UA/ChO, respectively. In addition, the half-life of the electrode was about seven days. In conclusion, we have successfully developed a Pt-based MPTMS/cholesterol oxidase heated electrode that can enhance cholesterol signals and minimally affected by the interferences of AA, AP and UA.

並列關鍵字

heating pad ； platinum nanoparticles ； cholesterol oxidase ； cholesterol ； Prussian blue

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