Biomimetic synthesis of gold nanoparticles (GNPs) is critical in biomedical applications. Gold bioconjugates were fabricated by capping the water-dispersible gold-carbon nanoparticles with tyrosine, tryptophan and cysteine amino acids. Incubation of the water-soluble and easily reducible aryldiazonium gold(III) salt [HOOC-4-C₆H₄N≡N]AuCl₄ with amino acids at room temperature formed a purple color over a few minutes with tryptophan and tyrosine and over two hours with cysteine. Rarely that cysteine is capable of reducing gold(III) precursors; however, a cysteine capped gold bioconjugate was synthesized and characterized in this study. Capping GNPs with amino acids was confirmed by high resolution transmission electron microscopy (TEM) and agarose gel electrophoresis. Depending on the amino acid, synthesized particles size was 27.2 ± 5.4 nm, 14.6 ± 7.7 nm and 8.6 ± 2.6 nm for tyrosine, tryptophan and cysteine, respectively. The amino acids capped GNPs showed negligible cytotoxicity to human dermal normal fibroblast cell lines. The highly water dispersible bioconjugates were studied for in vitro cellular uptake by HeLa cancer cells using confocal laser scan microscopy (CLSM) after being labelled with FITC (GNPs-COOH-FITC) and the nuclei were counter stained with DAPI fluorescent dyes. The biomimetic route for the synthesis of the amino acids reduced gold-carbon nanoparticles will benefit the applications in biomedical devices and biosensors.

中文翻译：

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从易于还原的芳基重氮四氯金酸盐（III）盐中高效合成氨基酸帽金纳米颗粒，用于细胞摄取研究。

金纳米颗粒（GNP）的仿生合成在生物医学应用中至关重要。通过用酪氨酸，色氨酸和半胱氨酸氨基酸覆盖水分散性金-碳纳米颗粒，制备了金生物共轭物。水溶性和容易还原的芳基重氮金（III）盐的孵育[HOOC-4-C ₆ H ^ ₄ N≡N] AUCL ₄氨基酸在室温下与色氨酸和酪氨酸在几分钟内形成紫色，与半胱氨酸在两小时内形成紫色。半胱氨酸很少能够还原金（III）的前体；然而，在这项研究中合成并表征了一个半胱氨酸帽的金生物共轭物。通过高分辨率透射电子显微镜（TEM）和琼脂糖凝胶电泳确认了用氨基酸封端的GNP。取决于氨基酸，酪氨酸，色氨酸和半胱氨酸的合成粒径分别为27.2±5.4 nm，14.6±7.7 nm和8.6±2.6 nm。氨基酸加帽的GNP对人真皮正常成纤维细胞系的细胞毒性可忽略不计。在用FITC（GNPs-COOH-FITC）标记后，使用共聚焦激光扫描显微镜（CLSM）研究了高水分散性生物缀合物在HeLa癌细胞的体外细胞摄取，并用DAPI荧光染料对细胞核进行了反染。用于氨基酸还原的金-碳纳米颗粒的合成的仿生途径将有益于生物医学设备和生物传感器中的应用。