幾丁聚醣輔助金奈米粒子修飾氧化銦錫電極之葡萄糖感測器

Abstract

研究以各種無機金屬、金屬氧化物或合金的奈米材料所製作非酵素修飾的葡萄糖感測電極，改善酵素型修飾電極缺點，提昇葡萄糖在電化學偵測上的穩定性，近來備受重視。 本研究利用微影製程與蝕刻方法，固定氧化銦錫（Indium-tin oxide, ITO）在玻璃上的面積，可以簡單生產出固定反應面積的 ITO 電極。結合單步驟的電沈積方法，將金奈米粒子修飾在 ITO 電極上，製作出一種可拋棄式的金奈米粒子修飾電極。藉著幾丁聚醣的輔助，將 ITO 電極置於濃度 400 mg/L 四氯金酸與 0.01% 幾丁聚醣的混合溶液中，定電位在 -0.8 V 維持 60 分鐘，ITO 電極的表面隨即生成一層由金奈米粒子所構成的穩定薄膜。經由 SEM 的觀察，可以清楚地得知金奈米粒子在電極表面堆積而成的立體奈米結構。在覆蓋 Nafion□ 薄膜將常見干擾物訊號排除之後，再針對修飾電極在葡萄糖偵測應用的分析效果做研究。該電極在 0.1 M NaOH 溶液中利用安培法偵測葡萄糖的靈敏度為 107.7 µA/mMcm2 ，偵測極限為 1.46 µM，而線性範圍則在 5 µM 到 2.3 mM 之間（R2 = 0.9991）。此外，由於電極的基底 ITO 導電玻璃是已在業界量產且品質穩定的材料，因此加工製作成 ITO 電極的成本不高，適合做為可拋棄式修飾電極的基材。

It has been paid much attention to develop nonenzymatic glucose electrochemical sensor by inorganic metal、metal oxid or alloy nanometerial, which would eliminate the instability problem of enzymatic glucose sensor. In this study, A disposable gold nanoparticles (AuNPs) modified ITO electrode, which the effect area was fixed by photolithography and etching technique, has been developed only with single step electrodeposition for glucose sensing. The AuNPs film on the electrode was formed by dipping the ITO electrode into the mixed solution containing 400 mg/L HAuCl4 and 0.01% chitosan and giving a reduction potential at -0.8 V (vs. Ag/AgCl) for 60 minute. The layer of the stacked AuNPs on the ITO surface was very stable and the nanostructure of this AuNPs modified sensor was performed by field-emission scanning electron microscope (SEM). After eliminating common interferences by Nafion□ covering, the analytical performance of the electrode for glucose detection was investigated. The sensitivity and the detection limit of the electrode were 107.7 µA/mMcm2 and 1.46 µM respectively in amperometric glucose sensing in 0.1 M NaOH solution. Linear range was from 5 µM to 2.3 mM (R2 = 0.9991). Since the ITO glass was obtained by low cost industrial production with stable quality, this substrate can be used as disposable material of sensor fabrication.