自古以來，發酵製程所生產的產品不勝枚舉，例如保養品、藥品、化學品和健康食物等，然而在實驗室規模或工業下，要優化現有製程或篩選菌種卻非常浪費時間、人力和金錢，因此為了減少勞動力和成本消耗，現今常利用微流體系統作為培養及分析的工具。未經處理的發酵液中含有多種成分，例如酵母菌的發酵液中含有琥珀酸、丙酮酸、乳酸等成分，故通常使用高效液相色譜法(high performance liquid chromatography, HPLC)作為成分分析的工具，對於微流體培養系統而言，由於其樣品量少，要利用HPLC作成分分析相當具有挑戰性。
本研究的重點在於開發可用於微流體發酵系統且具有快速和大偵測範圍的微型感測器整合系統，用於偵測代謝產物(如乳酸、乙醇)、營養源(葡萄糖)和環境pH值。本研究利用氧化鎳奈米顆粒修飾電極檢測代謝產物和營養源；利用氧化銥薄膜電極檢測環境pH值，上述氧化鎳奈米粒子及氧化銥薄膜修飾於金電極以及網版印刷碳電極表面，比較兩種不同電極的檢測效能。網版印刷碳電極偵測乳酸的平均靈敏度為11.74±1.05μA/mM，是金電極的2倍，兩者的線性偵測範圍皆為1 – 50mM，且在20天內的偵測表現相當穩定。網印碳電極對於乙醇亦有良好的偵測效能，檢測的線性濃度範圍為1 – 50mM、平均靈敏度為13.70±1.84μA/mM；然而，網版印刷碳電極在葡萄糖的偵測中極易被毒化，但金電極的穩定性可達17天，葡萄糖檢測的線性濃度範圍為1 – 20mM、平均靈敏度為27.09±3.04μA/mM。最後，碳印刷電極與金電極的pH檢測的線性範圍皆為pH 2 – 10、平均靈敏度皆為約54 mV/pH，穩定性可達8天。本研究中所有檢測都具有高度線性關係(R2 > 0.99)。

Yeast fermentation products contain multiple ingredients such as succinate, pyruvate, and acetate; and high performance liquid chromatography (HPLC) is commonly applied to the monitoring of these compositions. However, applying lab-scale fermentation for optimizing the process or screening high-yield strains can be time consuming, labor intensive, and sample devouring. Microfluidic platforms are currently more favorable setups for early-stage screening and optimization. Nonetheless, the minute sample amount in microfluidic setup is challenging for HPLC analysis. Therefore, this study focuses on the development of micro-sensors for rapid and high dynamic range detections not only in performing the monitoring of the metabolic products (lactic acid, ethanol…etc.) and the substrate (glucose) but also the pH environment in the micro-scale fermentation. The micro-sensors utilized the NiONPs/GO/Nafion/Au electrode and NiONPs/GO/Nafion/SPEs for detecting metabolic products and substrates while the IrOx electrode for pH measurements. Two kinds of microelectrodes, gold and screen-printed carbon, were applied and their performance was compared. Both electrodes had a linear detection range of 1 – 50 mM for lactate detection but the sensitivity of screen-printed carbon electrode had a sensitivity of 11.74±1.05μA/mM, which was two folds higher than the gold electrode. The screen-printed electrode also had good performance in ethanol detection: the detection range was 1 – 50 mM and the sensitivity was 13.70±1.84μA/mM. However, the screen-printed carbon electrode was highly prone to poisoning in glucose detection. The gold electrode showed stable detection of ethanol and glucose in 17 days. The glucose detection had a detection range of 1 - 20mM and a sensitivity of 27.09±3.04μA/mM. Both gold and screen-printed electrodes had a linear detection range for pH value from pH 2 to pH 10 with a sensitivity of 54 mV/pH. All detections were highly linear with correlation coefficients higher than 0.99.

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