Fluorescent-labelled nanoparticles conjugate the SPR of nanomaterials as well as the fluorescence properties of the capping dye. In this work, we report a study on the synthesis of fluorescent l-tyrosine (l-Tyr) and fluorescein (Fluo)-capped silver nanoparticles (AgNPs) carried out by a fine-tuning of the analytical concentration of the reagents. The AgNPs have been characterized by TEM, UV–Vis, ATR–FTIR, and photoluminescence (PL) spectroscopy and DLS. The adsorption of cysteine and homocysteine on the surface of the nanoparticles has been studied to evaluate their overall evolution in solution and their possible interactions with more complex systems, such as proteins. Opposed to homocysteine, cysteine induces aggregation either of tyrosine- and fluorescein-capped nanoparticles, which are therefore promising systems for the discrimination of biothiols. Furthermore, tyrosine-capped AgNPs, in spite of the better coordinating characteristics of this amino acid with respect to fluorescein, show aggregation abilities with cysteine greater than the fluorescein-capped ones that are unexpectedly more stable and thus less prone to aggregation phenomena.

中文翻译：

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新型荧光标记纳米颗粒：合成，表征和与半胱氨酸和高半胱氨酸的相互作用，以评估其在水溶液中的稳定性

荧光标记的纳米颗粒共轭纳米材料的SPR以及封端染料的荧光特性。在这项工作中，我们报告了有关荧光l-酪氨酸（l-Tyr）和荧光素（Fluo）封端的银纳米颗粒（AgNPs）通过微调试剂的分析浓度进行。AgNPs通过TEM，UV-Vis，ATR-FTIR，光致发光（PL）光谱和DLS进行了表征。已经研究了半胱氨酸和高半胱氨酸在纳米颗粒表面上的吸附，以评估它们在溶液中的整体演变以及它们与更复杂系统（例如蛋白质）的相互作用。与高半胱氨酸相反，半胱氨酸诱导酪氨酸和荧光素封端的纳米颗粒的聚集，因此，这是鉴别生物硫醇的有前途的系统。此外，酪氨酸封端的AgNP尽管该氨基酸相对于荧光素具有更好的配位特性，