自含檸檬酸鈉鍍浴中以微電鍍法製備銅鎳合金微柱並探討其對葡萄糖之感測特性

Fabrication of Cu-Ni alloying micropillarby Micro-Anode Guided Electroplating in sodium citrate bath and exploration of its sense on glucose

本論文採用微陽極導引電鍍法製備銅鎳合金微結構，分別控制銅鎳檸檬酸鹽鍍液之pH值自4.5至6.5以及改變電壓自4.0 V至4.6 V，並探討不同pH值對鍍液螯合物(Cu2Cit2H−1)3−以及(Cu2Cit2H−2)4−轉變之影響及反應機制。並以SEM觀察表面形貌，EDS分析化學組成、XRD分析晶體結構，以所得之結果與機械性質做討論。並以陰極極化及Comsol電場模擬解釋其反應機制。使用恆電位觀察銅鎳合金作為葡萄糖感測器之可行性，研究葡萄糖濃度對電化學測試之線性區間，及其對葡萄糖的靈敏度。由實驗結果得知:高鎳合金對葡萄糖之濃度變化感測較應靈敏，但線性區間較小。而高銅合金的感測靈敏度稍差，但線性區間大。本製程所得之銅鎳合金微柱屬於奈米晶粒，表面電催化活性區域大，能促進氧化過程的電子轉移，提升葡萄糖感測靈敏度。

Micropillars of copper-nickel alloys were prepared by micro-anode guided electroplating (MAGE) process. The effect of pH value in the Cu-Ni citrate baths ranging from 4.5 to 6.5, and the voltage changing from 4.0 V to 4.6 V was investigated. The reaction mechanism was found to correlate to the pH-dependence of the transformation between the chelates (Cu2Cit2H−1)3−and (Cu2Cit2H−2)4−. The information from surface morphology observed by SEM, chemical composition analyzed by EDS, and crystal structure analyzed by XRD was useful to delineate the mechanical properties of the micro pillars. The mechanism of MAGE is explored through the cathodic polarization and a simulation of electric field in terms of a commercial software Comsol. The sensing of Cu-Ni alloying pillars to the glucose was potentiostatically studied. The linear range of the current in response to glucose concentration was found to vary depending on the alloy composition. The Ni-enriched alloy takes the advantage of higher sensitive; however, Cu-enriched alloy benefits the test in a wider concentration of glucose. Comparing to the conventional sensor, the Cu-Ni micro pillars demonstrate a superior sensitivity in glucose sense. The excellent sensitivity is ascribed to their nanocrystals which offers higher electrocatalytic area to enhance the charge-transfer in the sensing of glucose.