利用網版印刷碳膠電極表面改質方式研究葡萄糖生物感測器的改良

Abstract

我們以葡萄糖生物感測器為模型，探討了幾種碳膠電極的改質方式來改善感測器的效能。首先，polypyrrole修飾的電極增加了對於葡萄糖的敏感度，相對的偵測電流值增加許多；但是polypyrrole本身並無法忍受高濃度的過氧化氫，過氧化氫會使polypyrrole氧化分解，導致無法偵測電流隨著使用次數降低，而無法繼續使用。另一種使用濺鍍方式，將鈀金屬沈積在電極表面上，此鈀金屬具有催化過氧化氫氧化的特質；再利用PVA-SbQ光敏感性高分子將葡萄糖氧化脢包埋固定在電極上，製作而成的生物感測器能偵測最低的濃度為500 nM的葡萄糖，檢測範圍為500 nM 至1000μM (R2= 0.997)，能長期保存三個月以及再現性良好( 濃度為10μM, R.S.D = 4.7% , n=20)。最後，將濺鍍上鈀金屬的電極再經過電漿化學蒸鍍處理賦予氨基在表面上，沈積上去的氨基供給戊二醛橋接酵素和電極，進而將酵素固定在電極上。此種作法由於酵素反應與電極表面極為接近，因此能得到快速的反應（約五秒內），且此種製作感測器方式，能加以延伸至生物微機電製程(BioMEMS)應用。

We developed glucose biosensor fabricating by several modification on the carbon paste electrode. First, the polypyrrole-modified electrode showed increasing response for sensing glucose. However, the inherent character of Ppy could not stand to the oxidative damage of hydrogen peroxide leading to degradation of the electrode. Second, we took advantage of thin-film technology to palladinized electrode by sputtering. Palladium has an excellent property to catalyst the final target, H2O2. Incorporate with PVA-SbQ immobilizing glucose, the glucose sensor exhibited high sensitivity (detection limit of 500 nM for glucose), long-term stability (retaining activity for 3 months) and good reproducibility (R.S.D = 4.2 % for 10μM glucose, n=20). Finally, we proposed a simple thin-film glucose biosensor based on a plasma- polymerized film. The amino group was deposited on the Pd-modified electrode so that there is a lot of available adherent site directly connect with the enzyme. Since the obtained film revealed a good interfacial design between enzyme and electrode surface, the rapid response time was achieved (~ 5sec). The most important is this design of biosensor is compatible for mass production in the filed of BioMEMS.