Ordered noble metal nanoparticles functionalized with organotrialkoxysilanes [e.g., 2-(3, 4-epoxycyclohexyl) ethyltrimethoxysilane (EETMS), 3-aminopropyltrimethoxysilane (APTMS), and 3-glycidoxypropyltrimethoxysilane (GPTMS)] were used as substrates to investigate the variation in fluorescence intensity of some well-known fluorophores (e.g., fluorescein, rhodamine, and l-tryptophan) based on distance effects and surface plasmonic activity. Anisotropic palladium nanoparticles (PdNPs), gold nanospheres (AuNPs), and silver nanospheres (AgNPs) were synthesized as a function of concentration of EETMS, APTMS, or GPTMS; the organotrialkoxysilane concentration directed the growth rate of particles along certain crystallographic facets. The reactive organic functionalities of alkoxysilanes facilitated the physisorption of probe molecules in proximity to the nanoparticles. The maximum enhancement in fluorescence intensity was observed in the case of APTMS-induced stabilization at hydrodynamic radii (RH) of ∼350 nm as a result of specific interactions with fluorescein molecules; quenching was mostly observed close for interactions between the GPTMS-functionalized nanoparticles and fluorophores. The smaller size of l-tryptophan and the absence of effective plasmonic coupling with PdNPs and AuNPs surfaces in the 290–370 nm emission range resulted in quenching; an appreciable far-field linking with AgNPs was noted around an emission wavelength of 360–375 nm, which resulted in several fold enhancement in intensity. Alkoxysilanes were shown to regulate the spatial control between the functionalized nanoparticles. As such nanoparticles, alkoxysilane-derived nanomaterials, may serve as promising platforms for metal enhanced fluorescence and fluorescence resonance energy transfer.

中文翻译：

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有机三烷氧基硅烷介导的贵金属纳米颗粒可控合成及其对选择性荧光增强和猝灭的影响

使用有机三烷氧基硅烷功能化的有序贵金属纳米粒子 [例如，2-(3, 4-环氧环己基) 乙基三甲氧基硅烷 (EETMS)、3-氨基丙基三甲氧基硅烷 (APTMS) 和 3-环氧丙氧基丙基三甲氧基硅烷 (GPTMS)] 作为底物来研究荧光强度的变化一些众所周知的荧光团（例如，荧光素、罗丹明和 l-色氨酸）基于距离效应和表面等离子体活性。各向异性钯纳米粒子 (PdNPs)、金纳米球 (AuNPs) 和银纳米球 (AgNPs) 被合成为 EETMS、APTMS 或 GPTMS 浓度的函数；有机三烷氧基硅烷的浓度控制着颗粒沿某些晶面的生长速度。烷氧基硅烷的反应性有机官能团促进了纳米颗粒附近探针分子的物理吸附。由于与荧光素分子的特定相互作用，在约 350 nm 的流体动力学半径 (RH) 处 APTMS 诱导稳定的情况下观察到荧光强度的最大增强；GPTMS 功能化纳米粒子和荧光团之间的相互作用主要观察到淬灭。l-色氨酸的较小尺寸以及在 290-370 nm 发射范围内与 PdNPs 和 AuNPs 表面缺乏有效的等离子体耦合导致猝灭；在 360-375 nm 的发射波长附近注意到与 AgNPs 的明显远场连接，这导致强度增加了几倍。烷氧基硅烷显示调节功能化纳米粒子之间的空间控制。作为这样的纳米粒子，烷氧基硅烷衍生的纳米材料可以作为金属增强荧光和荧光共振能量转移的有前途的平台。