還原石墨烯氧化物、奈米銀及銅之複合薄膜於生物感測器之應用

Reduced graphene oxide and nano silver and copper composite film in biosensor applications

陳盈慧(Ying-Hui Chen)

指導教授 ： 陳生明 ； 連萬福 ； 洪偉修

國立臺北科技大學/工程學院/化學工程研究所/碩士(2014年)

https://doi.org/10.6841/NTUT.2014.00183

摘要

第一部分：本實驗介紹了化學法還原石墨烯氧化物（CRGO）修飾玻璃碳電極（GCE）用於咖啡酸（CA）的電化學研究。以循環伏安法（CV）、微分脈衝伏安法（DPV）、安培和電化學阻抗譜（EIS）等方法測試電極的性能與表徵。結果顯示有一個明顯增強的電流響應與降低的過電位，此為CA之氧化。用EIS 對CA的界面電子轉移速率進行研究。在最佳條件下，該CRGO顯示其線性響應範圍為1×10-8 ~ 8×10-4 M，偵測極限為2×10-9 M（S / N= 3），當電位在 +0.2 V (Ag / AgCl)時其靈敏度為192.21 μA mM−1 cm−2，這表示在CA的電化學研究上，CRGO是種很有前景的感測材料。結果顯示了良好的靈敏度和選擇性以及CRGO修飾電極高的可重複性。此外，將修飾電極更進一步應用於研究紅酒之實際樣品中的CA，其結果令人滿意。

第二部分：銀奈米粒子透過環保的化學方法做快速合成，是非常可行的方式。在這個研究中，我們已經開發出一種方法，透過混合銀溶液與Chenopodium ambrosioides L的葉子提取物以生物合成的方式產生銀奈米粒子。該方法在生物學中是穩定的，且有生物相容的奈米銀粒子形成。這些奈米顆粒通過各種表徵技術分析，以了解它們的形態、化學組成和生物活性。從SEM，FE-SEM和AFM分別可計算平均晶粒尺寸。其粒徑範圍為100至300奈米，且有板狀和球形結構的形狀，可用改變反應溫度和葉子汁的濃度來進行控制。葉子提取物的濃度和金屬離子在銀奈米粒子的綠色合成中有重要的作用。根據XRD光譜特性研究和循環伏安法（CVS）來證明生物合成的銀奈米粒子的形成和穩定性。這個簡單、高效且快速的環保合成銀奈米粒子能在各種生物醫學和生物技術中應用。此環保的生物銀奈米粒子的合成方法有可能直接應用在與人體接觸的各種產品，如化妝品、食品、消費品、醫療用品。更詳細的研究則要釐清其生物奈米顆粒合成的機制。這個簡單、成本低、且環保的方法對於金屬奈米粒子的開發會在環保、生物技術和生物醫學應用是有價值的。

第三部分：利用新型的銅和silicomolybdate（SiMO）複合薄膜修飾多壁奈米碳管（CuSiMO/MWCNT），已成功用電沉積製備出高靈敏度的過氧化氫感測器，來檢測非酶過氧化氫（H2O2）。XRD和SEM分析顯示，Cu和SiMO成功沉積於MWCNT上，此為雜化複合物。在中性條件下，電極對H2O2有好的還原活性，且具有低的過電位（-0.16 V），其電流響應2.7 - 62.8倍。而最大電流響應是在pH 1中。電流響應（Eapp = -0.1 V）顯示的線性範圍可達5.2×10-3 M，具有650 μA mM-1 cm-2的高靈敏度，6.53×10-6 M（S / N = 3）低的偵測極限，響應時間為5秒。該CuSiMO/MWCNT電極可分析H2O2是有前景的，因為它有低的過電位，靈敏度高，穩定性好，響應速度快，成本低。

關鍵字

生物奈米技術 ； 化學還原石墨烯氧化物 ； 電化學阻抗譜 ； 咖啡酸 ； 電化學 ； 銀奈米粒子 ； 綠色化學 ； 生物合成

並列摘要

Part 1 ：The present work describes the characterization of a chemically reduced graphene oxide (CRGO) modified glassy carbon electrode (GCE) for electrochemical investigation of caffeic acid (CA). Cyclic voltammetry (CV), differential pulse voltammetry (DPV), amperometry, and electrochemical impedance spectroscopy (EIS) techniques were used to characterize the properties of the electrode. There was an obvious enhancement of the current response and a decreased over potential for the oxidation of CA. The interfacial electron transfer rate of CA was studied by EIS. Under optimal conditions, the CRGO displayed a linear response range of 1×10-8 to 8×10-4 M and the detection limit was 2×10-9 M (S/N = 3), with a sensitivity of 192.21 μA mM-1 cm-2 at an applied potential of +0.2 V (vs. Ag/AgCl reference), which suggests that the CRGO is a promising sensing materials for the electrochemical investigation of CA. The results showed the good sensitivity, selectivity and high reproducibility of the CRGO modified electrode. Moreover, this modified electrode was further applied to investigate the CA in real samples of wine with satisfactory results.

Part 2 ：Rapid synthesis of silver nanoparticles through economically feasible green chemistry approach is highly desirable. In this study we have developed a method to biosynthesize silver nanoparticles by mixing silver solution with leaf extract of Chenopodium ambrosioides L. In this method, physiologically stable, bio-compatible Ag nanoparticles (AgNPs) were formed. These nanoparticles were analyzed by various characterization techniques to reveal their morphology, chemical composition, and bioactivity. Average crystal size calculated from SEM, FE-SEM and AFM respectively. The particle size ranging from 100 to 300 nm and the shape of the plate and spherical structures could be controlled by changing the reaction temperature and leaf broth concentration. The concentrations of leaves extract and metal ion are playing an important role in the green synthesis of AgNPs. The spectroscopic characterizations from XRD and Cyclic voltammetry (CVs) support the formation and stability of the biosynthesized AgNPs. This simple, efficient and rapid green synthesis of AgNPs can be used in various biomedical and biotechnological applications. This environmentally friendly method of biological AgNPs synthesis can potentially be applied in various products that directly come in contact with the human body, such as cosmetics, foods, and consumer goods, besides medical applications. More elaborate studies are required to elucidate the mechanism of biological nanoparticles synthesis. This simple, low cost and greener method for development of AgNPs may be valuable in environmental, biotechnological and biomedical applications.

Part 3 ：Novel copper and silicomolybdate (SiMO) decorated multi-walled carbon nanotubes (CuSiMO/MWCNT) have been successfully fabricated for nonenzymatic hydrogen peroxide (H2O2) detection by the electrocodeposition of copper and silicomolybdate on a MWCNT-modified electrode. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses reveal that the Cu and SiMO were successfully deposited on the MWCNT in this hybrid composite. In neutral condition, the electrode shows good activity towards H2O2 reduction with low overpotential (-0.16 V) and a current response that is 2.7–62.8 times greater than that obtained using Cu, MWCNT, Cu/MWCNT, and CuSiMO. The maximal current response is found at pH 1. Amperometric response (Eapp. = -0.1 V) indicates a linear range up to 5.2×10-3 M and with high sensitivity of 650 μA mM-1 cm-2; a low detection limit of 6.53×10-6 M (S/N = 3), and a response time of 5 s. The CuSiMO/MWCNT electrode can analyse H2O2 promising a nonenzymatic H2O2 sensor due to its low overpotential, high sensitivity, good stability, fast response, and low cost.

並列關鍵字

Bionanotechnology ； Chemically reduced graphene oxide ； Electrochemical impedance spectroscopy ； Caffeic acid ； Electrochemistry ； silver nanoparticles (AgNPs) ； green chemistry ； Biological synthesis

參考文獻

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