電化學法製備發光碳奈米點並應用於銅離子檢測

Electrochemical Preparation of Photoluminescent Carbon Nanodots and Their Application as Copper Ions Sensor

林雅玲(Yaling Lin)

指導教授 ： 張煥宗

國立臺灣大學/理學院/化學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201801248

摘要

本研究我們利用一種簡易、快速、環保的電化學合成方法，以組胺酸（histidine）作為前驅物，在室溫、鹼性及10伏特的恆定電壓下，不需添加任何有毒試劑與有機溶劑即可製備碳奈米點（Carbon Nanodots, C dots）。同時探討組胺酸濃度、反應pH值、反應時間及添加鹵化鈉（氯化鈉、溴化鈉和碘化鈉）等條件對於碳奈米點性質的影響。最佳化條件為0.63 M組胺酸，pH 9.0，1 M鹵化鈉。此方法具有成本低、反應時間短、所需能量低及可隨時觀察螢光（photoluminescence, PL）變化等優點。由於鹵素離子之親和性及離去能力差異，使加入氯化鈉、溴化鈉和碘化鈉所製備的碳奈米點（Cl-C dots, Br-C dots, I-C dots）具有不同的形成速率。在加入鹵化鈉條件下製備的碳奈米點在高鹽類濃度（0－3.0 M）、不同pH值下（3.0－11.0）及在1小時光照下皆有良好的光穩定性。相較於C dots、Cl-C dots及Br-C dots，I-C dots檢測銅離子（Cu2+）的選擇性及靈敏度高，由循環伏安法（CV）及X射線光電子能譜（XPS）等結果可得知I-C dots能與Cu2+形成金屬配體錯合物並進一步發生電荷轉移（charge transfer），進而使I-C dots的螢光猝滅。在最佳化條件下，其線性範圍為0.3－3.0 μM，偵測極限為0.22 μM。此外，I-C dots也可以應用於實際樣品如自來水，湖水及海水中Cu2+的檢測。由於I-C dots具有製備時間短、光穩定性高、檢測Cu2+的選擇性及靈敏度高等優點，相信在未來可用於檢測活細胞及血液等複雜基質中的Cu2+。

關鍵字

電化學 ； 組胺酸 ； 碳奈米點 ； 螢光 ； 猝滅 ； 鹵化鈉 ； 銅離子

並列摘要

We used a simple, fast, eco-friendly electrochemical strategy to prepare carbon nanodots (C dots) from histidine under alkaline conditions by applying a constant voltage of 10 V at room temperature without using any toxic chemicals and organic solvents. The effects of concentrations of histidine, pH, reaction time and sodium halides such as sodium chloride (NaCl), sodium bromide (NaBr), and sodium iodide (NaI) on the properties of as-prepared C dots were investigated. The optimal conditions to prepare C dots are 0.63 M histidine, pH 9.0 and 1 M sodium halides. This method has the advantages of low-cost, short reaction time, low energy and the photoluminescence (PL) is observable at any time. The formation rates of C dots synthesized by adding NaCl, NaBr and NaI (Cl-C dots, Br-C dots, I-C dots) was controlled through the differential nucleophilicity and leaving ability of sodium halides. The C dots prepared in presence of sodium halides exhibits high photostability at high concentrations of salts (0-3.0 M), different pH (3.0-11.0) and 1 h irradiation. Compared to C dots, Cl- or Br-C dots, I-C dots shows high selectivity and sensitivity toward the Cu2+ ions. Cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS) results confirmed the formation of metal-ligand complexes between Cu2+ ions and I-C-dots and the charge transfer leading to the PL quenching of I-C dots. The I-C dots allowed detection of Cu2+ ions, with a limit of detection (LOD) and a linear range of 0.22 μM and 0.3-3.0 μM, respectively. Furthermore, the practicality of I-C dots toward the detection of Cu2+ ions in real samples such as tap water, lake water and seawater was demonstrated. Having advantages such as short preparation time, high photostability, high selectivity and sensitivity, I-C dots are holding great potential for the detection of Cu2+ ions in complex matrices such as living cells and blood.

並列關鍵字

electrochemical ； histidine ； carbon nanodots ； photoluminescence ； quenching ； sodium halides ； Cu2+ ions

參考文獻

第一章

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