羧基化奈米碳管修飾網版印刷碳電極對鳥糞嘌呤與腺嘌呤的電化學分析

本論文利用羧基化多壁奈米碳管(MWCNT-COOH)修飾網版印刷碳電極(SPCE)，並用SPCE/MWCNT-COOH在pH 7.0環境下，於每次偵測前給予7分鐘的accumulation time (open circuit)來偵測鳥糞嘌呤(guanine, G)與腺嘌呤(adenine, A)，並發現此修飾電極具有良好的催化活性。我們也利用穿透式電子顯微鏡與掃描式電子顯微鏡觀察MWCNT-COOH修飾溶液的分散情形與SPCE/MWCNT-COOH的地貌。我們利用循環伏安法(CV)偵測guanine與adenine，在濃度範圍0.08 ~ 4.00 μM與0.24 ~ 4.00 μM之間，其濃度校正曲線斜率(靈敏度)為43.44 μA/μM與29.47 μA/μM，偵測極限為24.90 nM與56.17 nM。接著我們進一步利用差式脈衝伏安法(DPV)以降低其偵測極限，偵測guanine與adenine分別在濃度範圍0.04 ~ 1.15 μM與0.12 ~ 3.50 μM之間，其濃度校正曲線斜率(靈敏度)為14.53 μA/μM與10.79 μA/μM，偵測極限為8.90 nM與18.91 nM。使用小牛胸腺DNA作為真實樣品的實驗中，在濃度範圍為0.10 ~ 1.00 μg/mL DNA中所偵測到的(C+G)/(A+T)=67%，偵測極限為12.55 ng/mL。

關鍵字

奈米碳管；鳥糞嘌呤；腺嘌呤；電催化

並列摘要

In this work, we prepared carboxylated multi-walled carbon nanotubes modified screen-printed carbon electrodes (SPCE/MWCNT-COOH) by a simple deposition method. Electrochemical oxidation of guanine and adenine in pH 7.0 with 7 min. accumulation time (open circuit) were conducted, and showd excellent catalytic activity. The MWCNT-COOH modified solution and the SPCE/MWCNT-COOH modified electrodes were characterized by transmission electron microscopy(TEM) and scaning electron microscopy (SEM). A linear calibration plots of guanine (0.08 - 4.00 μM) and adenine (0.24 - 4.00 μM) were obtained by cyclic voltammetries, the sensitivities were 43.44 μA/μM and 29.47 μA/μM, and the detection limits were 24.90 nM and 56.17 nM, respectively. A linear calibration plots of guanine (0.04 - 1.15 μM) and adenine (0.12 – 3.50 μM) were obtained by difference pulse voltammetries, the sensitivities were 14.53 μA/μM and 10.79 μA/μM, and the detection limits were 8.90 nM and 18.91 nM, respectively.A linear calibration plots of calf thumus DNA (0.10 - 1.00 μg/mL) were obtained by difference pulse voltammetries, the (C+G)/(A+T)=67%, and the detection limit of calf thumus DNA was 12.55 ng/mL.