雷射誘發前向轉移於葡萄糖感測元件之製作

Abstract

本研究利用雷射誘發前向轉移(Laser-induced forward transfer, LIFT)之技術應用於製作葡萄糖感測元件，不需透過光罩、模具即可完成電極之列印，透過電腦設計電極圖案，匯入圖檔即可完成電極之設計及製作，可以簡單並且快速地改變電極設計。製程中不需處於真空環境，亦不使用有毒之化學液體，對環境之負擔亦較小。 本研究採用三電極之電化學感測器，參考電極為氯化銀(Ag/AgCl)，輔助電極為銅(Cu)，而工作電極為氧化銅(CuO)。本研究使用雷射誘發前向轉移(LIFT)之技術將銅(Cu)列印至PET撓性基板上，作為各電極之導線，氧化銅(CuO)之製作利用雷射誘發氧化(LIO)技術，透過雷射施加能量將轉印成功、位於工作電極範圍之銅(Cu)氧化，形成氧化銅；參考電極則使用購置之氯化銀漿塗覆並風乾。列印完成後分別測試各材料之薄膜電性，利用光學顯微鏡觀察其列印品質，並利用EDS分析判斷氧化銅(CuO)之生長情形。封裝後，完成本研究感測元件之製作，而後進行電化學實驗，找到其線性範圍、感測極限以及靈敏度。 雷射誘發前向轉移列印銅薄膜相關實驗之結果，當雷射能量密度大於1471.30 mJ/cm2時，能成功完成銅薄膜之列印。當雷射光斑重疊率為13.4 %時，電阻為最低。而在雷射能量密度為1768.39 mJ/cm2以及光斑重疊率為13.4 %時，最低片電阻為19.7 (Ω/square)。 雷射誘發氧化製程之實驗結果，當雷射能量密度大於442.1 mJ/cm2時，即把銅薄膜幾乎剝蝕，僅殘留少部分之銅於PET基板上，根據實驗結果雷射能量密度需小於271.35 mJ/cm2才可進行雷射誘發氧化加工。透過EDS分析，結果顯示原始列印之銅薄膜其銅氧比約為20 %，而當雷射誘發氧化之雷射輸出功率為1.75 W時，其薄膜銅氧比達到最高約42 %。 進行電化學實驗之循環伏安法時，其結果顯示工作電極之銅氧比為42 %時，其循環伏安圖約於+0.6 V附近，有一明顯之氧化峰，其結果證明了透過增加雷射輸出功率，能夠增強其感測元件對於葡萄糖之催化性能。亦使用計時電流法探討本研究製作之感測元件於葡萄糖之感測性能，靈敏度約為96 μAmM-1cm-2，LOD為115.65 μM，電流響應之線性度其R2為0.956，故本研究製作之感測元件適用於量測濃度範圍為1~11 mM之葡萄糖溶液。

In this study, the laser-induced forward transfer (LIFT) technology was applied to the manufacture of glucose sensors, and the electrodes can be printed without pho-tomasks or molds. The process does not require a vacuum environment and does not use toxic chemicals, so the environmental burden is less. In this study, a three-electrode electrochemical sensor was used, with silver/silver chloride (Ag/AgCl) as the reference electrode, copper (Cu) as the counter electrode, and cupric oxide (CuO) as the working electrode. In this study, copper (Cu) was printed onto a PET flexible substrate using the laser-induced forward transfer (LIFT) technique as conductive tracks for each electrode. Cupric oxide (CuO) was fabricat-ed using the laser-induced oxidation (LIO) technique to oxidize copper (Cu) in the working electrode area by applying laser power to the electrodes. The reference electrodes are coated with purchased silver chloride paste and air-dried. After print-ing, the electrical properties of each material were tested separately. The electrodes quality was observed using an optical microscope, and EDS analysis was used to de-termine the growth of CuO. After packaging, the fabrication of the sensor is com-pleted and electroanalytical methods are conducted to find the linearity range, limit of detection, and sensitivity. The results of the laser-induced forward transfer printing of copper thin films were obtained when the laser energy density was greater than 1471.30 mJ/cm2. The lowest resistance was achieved when the overlapping rate was 13.4 %. The lowest sheet re-sistance was 19.7 (Ω/square) at a laser energy density of 1768.39 mJ/cm2 and the overlapping rate of 13.4 %. According to the experimental results of the laser-induced oxidation process, when the laser energy density was greater than 442.1 mJ/cm2, the copper film was almost peeled off and only a small portion of the copper remained on the PET substrate. The EDS analysis showed that the copper-to-oxygen ratio of the original printed copper film was about 20 %, and the highest copper-to-oxygen ratio was about 42 % when the laser output power of the laser-induced oxidation was 1.75 W. The cyclic voltammetry demonstrates a clear anodic peak around +0.6 V at the working electrode with a 42 % copper-to-oxygen ratio, which proved that the elec-trocatalytic activity for glucose could be enhanced by increasing the laser power. The sensitivity was about 96 μAmM-1cm-2, the LOD was 115.65 μM, and the linear behavior with an R2= 0.956. As a result, the sensor was suitable for measuring glu-cose solutions in the concentration range of 1~11 mM.