金奈米團簇(gold nanocluster, AuNCs)是由幾個至數十個的金原子所組成，尺寸小於2 nm，具有好的光穩定性、大的 Stokes shift、較長的螢光生命週期以及佳的生物相容性，因此讓其應用受到廣泛的關注。再加上金奈米團簇放光位於近紅外光區間 (700-900 nm) 有較小的自體螢光干擾和吸收係數，能夠穿透至更深的生物組織中，使的在生物成像和感測更具吸引力。
本研究首先以三種不同胜肽鏈 (RCR, Arg-Cys-Arg、KCK, Lys-Cys-Lys、GCG, Gly- Cys- Gly) 作為模板合成近紅外光 (NIR) 放光的金奈米團簇。接著將聚合物:聚丙烯酸 (Poly acrylic acid, PAA) 修飾上硫醇分子，形成硫化聚丙烯酸(Thiolated- Poly acrylic acid, TPAA) ，之後將三種不同胜肽金奈米團簇，與硫化聚丙烯酸反應。卻發現RCR-AuNCs相較於其他兩種短鏈胜肽GCG、KCK有良好的鍵結效果，其原因可能是R (argnine) 胺基酸有類似雙牙基的結構所導致，其側鏈上含有兩個胺基可以與TPAA上的羧基基團形成雙齒配位鍵，進而增強結合力，以靜電吸引力鍵結方式合成穩定的金奈米團簇聚集物，硫醇氧化所形成的雙硫鍵會使之互相交聯，讓金奈米團簇聚集物尺寸增加，因此可以透過離心進行純化，得到RCR-AuNCs@TPAA複合材料來進行後續實驗。
接著將合成出的RCR-AuNCs@TPAA複合材料對銅離子進行檢測，發現其螢光強度會隨著銅離子濃度增加而導致螢光淬滅現象，該機制受光誘導電子轉移 （Photoinduced electron transfer, PET） 影響導致消光，且該探針具有高靈敏度、良好的選擇性和快速檢測的能力，其偵測極限為0.22 nM，並應用於檢測真實樣品中的飲用水，未來將有更大潛力應用於生物方面應用。

Gold nanoclusters (AuNCs) are fluorescent material composed of a small number of gold atoms. Their unique optical properties, including high photostability, large Stokes shift, and long fluorescence lifetime, make them ideal for various biomedical applications. The near-infrared emission (700-900 nm) of AuNCs minimizes autofluorescence and enables deeper tissue penetration, making them particularly attractive for bioimaging and biosensing.
In this work, near-infrared (NIR) emitting gold nanoclusters (AuNCs) were synthesized using three different peptide templates: RCR (Arg-Cys-Arg), KCK (Lys-Cys-Lys), and GCG (Gly-Cys-Gly). Thiolated polyacrylic acid (TPAA) was prepared by modifying polyacrylic acid (PAA) with thiol molecules. Subsequently, the three types of peptide-AuNCs were reacted with TPAA. The results revealed that RCR-AuNCs exhibited significantly better binding affinity compared to the other two short peptide-AuNCs (GCG and KCK). This enhanced binding is attributed to the bidentate nature of the arginine (R) amino acid, whose side chain contains two amino groups capable of forming bidentate coordination bonds with the carboxyl groups of TPAA. This electrostatic attraction facilitated the formation of stable AuNCs aggregates. Furthermore, the disulfide bonds formed by thiol oxidation cross-linked the aggregates, leading to an increase in their size. Consequently, the RCR-AuNCs@TPAA composites could be purified by centrifugation for subsequent experiments.
The synthesized RCR-AuNCs@TPAA composites were employed for the detection of copper ions. The fluorescence intensity of the composites was found to be quenched upon increasing the concentration of copper ions, indicating a photoinduced electron transfer (PET) quenching mechanism. This probe exhibited high sensitivity, selectivity, and rapid response, with a detection limit of 0.22 nM. The practical application of this probe was demonstrated by detecting copper ions in real water samples. This study suggests that RCR-AuNCs@TPAA composites have great potential for various biological applications.

論文審定書 i
誌謝 ii
摘要 iii
Abstract iv
目 錄 vi
圖　次 ix
表 次 xv
1 前言 1
1.1近紅外光金奈米團簇（AuNCs） 1
1.2以胜肽鏈合成的金奈米團簇 5
1.3硫醇化聚合物 9
1.4銅離子檢測 10
1.5淬滅機制-光誘導電子轉移（Photoinduced electron transfer, PET） 15
1.6研究動機 18
2實驗部分 19
2.1實驗藥品 19
2.2儀器設備 20
(1) 螢光光譜儀 (Fluorescence spectrometer) 20
(2) 雙光束紫外光/可見光光譜儀 (Double-beam UV-visible spectrophotometer) 20
(3) 粒徑分析儀 (Dynamic light scattering, DLS) 20
(4) 粒徑與界面電位分析儀 (Zeta potential) 21
(5) 高解析電子能譜儀 (High resolution X-ray photoelectron spectrometer) 21
(6) 軟物質專用穿透式電子顯微鏡 (Transmission electron microscope, TEM) 21
(7) 螢光生命週期儀 (Fluorescence lifetime Spectrometer) 22
(8) 紫外光電子能譜 (Ultraviolet Photoelectron Spectroscopy) 22
(9) 原子吸收光譜 (Atomic absorption spectroscopy, AA) 22
2.3材料合成 23
2.3.1合成不同種peptide-AuNCs 23
2.3.2合成硫化聚丙烯酸(Thiolated-Polyacrylic acid, TPAA) 24
2.3.3合成RCR-AuNCs@TPAA 24
2.4 DTNB染劑測試(Ellman's reagent) 24
2.5穩定性測試 25
2.6選擇性測試 25
2.7銅離子定量 26
2.8真實樣品檢測 26
3 結果與討論 27
3.1 透過不同短鏈胜肽為模板合成近紅外光的金奈米團簇 27
3.2 不同種類 peptide-Au NCs 在不同 pH 值下的表面電位 45
3.3 硫化聚丙烯酸(TPAA)的鑑定 49
3.4 硫化聚丙烯酸(TPAA)和不同種類 peptide-AuNCs的結合 54
3.5 RCR-AuNCs@TPAA的鑑定與光學分析 60
3.6 RCR-AuNCs和RCR-AuNCs@TPAA在生理條件下測試 70
3.7 利用RCR-AuNCs@TPAA檢測銅離子 74
3.7.1 RCR-AuNCs@TPAA探針與銅離子之反應條件優化探討 77
3.7.2 RCR-AuNCs@TPAA探針與銅離子之選擇性探討 82
3.8螢光淬滅機制 85
3.9 真實樣品檢測 95
4 結論 97
參考文獻 98

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