以綠色環保方法合成金奈米粒子與其生醫上的應用

Green Synthesis of Gold Nanoparticles for Biomedical Applications

王珈宜(Jia-yi Wang)

指導教授 ： 朱智謙

中山醫學大學/健康管理學院/公共衛生學系/碩士(2016年)

摘要

本篇論文透過雷射誘導方式及生物合成法這兩種方法來製備金奈米粒子，這兩種的製備方法兼具操作簡單及環保效益兩項優點。在雷射誘導方式的研究中，我們將文獻裡利用UVA光來催化製備出金奈米粒子後，透過532 nm Nd：YAG雷射消熔來修飾其金奈米粒子大小及形狀的方式加以改良，省略用UVA光來催化製備金奈米粒子的步驟，而是將四氯金酸鹽溶液加入過氧化氫後，直接照射532 nm Nd：YAG雷射來誘導製備出具有表面電漿共振吸收的金奈米粒子，其粒徑約在8.27±3.30 nm左右。而在雷射誘導製備的過程中為了提高金奈米粒子穩定性，添加外圍修飾上偶氮苯分子的第四代PAMAM樹枝狀高分子(G4-Az)作為穩定劑，而且經過氧化處理後的樹枝狀高分子衍生物可發出藍色螢光。基於順式Az通常無法吸收350-400 nm的UV光，我們藉此可以用來調控樹枝狀高分子的螢光強度。根據上述結果原本粒徑在10 nm以上的金奈米粒子其螢光量子效率極低，我們將G4-Az與金奈米粒子結合，讓金奈米粒子產生藍色螢光外，並透過UV與可見光循環照射來調控金奈米粒子的螢光強度。另外在生物合成法中，我們利用蘋果萃取液來作為還原劑，製備出均勻分散且平均粒徑在22.06±5.69 nm的金奈米粒子。此外我們透過DPPH radical assay抗氧化測試發現，蘋果萃取液中含有金奈米粒子具有延長其抗氧化能力的效果，所以我們進一步利用高速離心的方式將蘋果萃取液中的金奈米粒子離心回溶後，利用電子順磁共振光譜儀(EPR)測試發現金奈米粒子濃度在3 mg/ml時其抗氧化能力高達80%。本篇論文利用雷射誘導方式及生物合成法製備出來的金奈米粒子，預期未來在生醫影像、生物感測器以及保健食品上有相當不錯的發展潛力。

關鍵字

金奈米粒子 ； PAMAM樹枝狀高分子 ； 偶氮化合物 ； 抗氧化活性。

並列摘要

In this research, we have developed the “green” routes for the preparation of gold nanoparticles (AuNPs) by laser-induced and biogenic approaches. The two methods have advantages of facile preparation in eco-friendly conditions. According to the literatures, polygonal gold nanoclusters could be photohemically synthesized with UV light irradiation, followed by 532 nm Nd:YAG laser ablation to yield the AuNPs with uniform size and shape. In this study, we report a novel laser-induced synthesis for spherical gold nanoparticles with the dimension of 8.27±3.30 nm. In addition, we have synthesized an Az chromophore-grafted PAMAM dendrimer (G4-Az) bearing significant blue fluorescence upon oxidative treatment as the stabilizer for AuNPs. Because the fluorescent quantum efficiency of diameter more than 10 nm gold nanoparticles is extremely low, G4-Az makes AuNPs have remarkable blue fluorescence. Most importantly, this photoresponsive macromolecular probe can achieve fine adjustment of the emission intensity of AuNPs upon alternating UV and visible light stimulation. In biogenic approach, we use apple extracts to synthesize the AuNPs, which are fairly monodisperse with an average size of 22.06±5.69 nm. The DPPH radical assay shows that apple extracts containing AuNPs possess prolonged antioxidant capacity than pristine apple extracts do. Moreover, the AuNPs can be further collected by high-speed centrifugation and redisperse into water. The spectroscopic and electron spin resonance (ESR) analyses indicate that approximate 80% of DPPH radicals were scavenged by thus-prepared AuNPs at the concentration of 3 mg/ml. The AuNPs prepared by laser-induced and biogenic approaches have excellent potentials in biomedical imaging, biosensors and healthy food technology.

並列關鍵字

Gold nanoparticles ； PAMAM dendrimers ； azo compounds ； antioxidant.

參考文獻

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