超奈米微晶鑽石薄膜在生醫上的應用

植入式生物感測器對生物本體來說屬於外來物質，在植入手術的過程中與植入後常因為植入材料與患者免疫系統交互作用而引發一些併發症，例如：免疫排斥反應、腫瘤形成、感染等，進而影響了生物感測器的效能。有鑒於超奈米微晶鑽石薄膜（UNCD）的生物相容性、化學惰性與可調控的導電度，本研究主要將評估 UNCD在植入式生物感測器的應用，首先先探討UNCD作為感測器披覆層的可行性，進一步以偵測神經傳導物質多巴胺（Dopamine, DA）為例子，評估UNCD作為感測器工作電極的潛力。實驗結果顯示，經氧氣電漿處理後的僅約300 nm的UNCD薄膜最適合作為感測器的披覆層，主要是因為UNCD表面越平坦，總表面積小，植入動物體內後，吸附體液中較少量的纖維蛋白後，進而降低急性炎症反應，而減少生物體對材料的免疫反應。在工作電極的研究部分，經由在氮氣電漿中成長導電的NUNCD，以電化學的方式對多巴胺（DA）進行感測，在有干擾物（抗壞血酸（AA）和尿酸（UA））的環境下，偵測極限仍可以達到0.32μM，此外，藉由開發鹼性清洗步驟，可以提高回收率（Recovery）達90－120%，證明此電極具有良好的「可重複使用性」。從以上研究得知，UNCD薄膜作為植入式生物感測器的披覆層具有極佳的化學穩定性與生物惰性，作為生物感測器的工作電極而言，也具有極佳的專一性、靈敏度與可靠度。

關鍵字

超奈米微晶鑽石薄膜；生物感測器；植入式晶片披覆層

並列摘要

Implantable biosensors (including cochlear implants, pacemakers ... etc.) belong to foreign substances to human bodies, so it cannot avoid some of the complications with the implant during or after implantation process (such as a tumor, infection, etc. illness). In this study, the ultrananocrystalline diamond thin film (UNCD) as implantable microchip encapsulation layer was used to improve/reduce the interactions between inter-implanted material and host tissue and then evaluating its potential as a biosensor for detecting dopamine. First, using microwave plasma enhanced chemical vapor deposition (MPECVD) under Ar-rich (99%)/CH_4 (1%) plasma to grow double-sided coated UNCD film on 5 % HF pretreated Si microchips. Results show that the smother surface of UNCD films with only 300 nm in thickness results less absorbed fibrinogen adsorption, which further not only decreased the acute inflammatory response, but also caused thinner fibrous tissue. Secondly, traditional dopamine sensing methods were confronted with problems such as interference and biofilm-fouling. This study adopted electrochemical method to detect dopamine, and the electrode we used was conductive nitrogen-incorporated ultrananocrystalline diamond (NUNCD) film that was prepared through the biased enhanced CVD growth method. For the dopamine detection in the phosphate buffer solution, the detection limit was about 0.32 μM. In the presence of interference includes ascorbic acid and uric acid, the detection limit was still about 0.32 μM. In fetal bovine serum, the electrode also performed excellently with a detection limit of about 0.39 μM. Moreover, the recovery of the electrode is about 90-120%, indicating that the NUNCD film has great potential to be used as an electrode for dopamine sensing.

並列關鍵字

Ultra-nanocrystalline diamond films ； biosensor ； implantable insulating coating layer

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超奈米微晶鑽石薄膜在生醫上的應用

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