Plasmon-Enhanced Fluorescence of Carbon Nanodots in Gold Nanoslit Cavities
Plasmon-Enhanced Fluorescence of Carbon Nanodots in Gold Nanoslit Cavities
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DOI：
10.1021/acs.langmuir.9b00448
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发表时间：
2019-07-09
期刊：
影响因子：
3.9
通讯作者：
Wei, Jianjun
中科院分区：
文献类型：
--
作者：
Bagra, Bhawna;Zhang, Wendi;Wei, Jianjun
碳纳米点（CND）具有广泛的光吸收和激发依赖性荧光。CND的发光增强是纳米光子学发展的一个重要方面。虽然量子点和分子染料的等离子体增强荧光现象已经得到了很好的研究，但很少有关于CND的报道。在这项工作中，一系列的等离子体纳米缝的设计制造和用于固定的纳米缝和检查的最佳匹配的等离子体荧光增强的CND。在演唱会上，为了更好地了解增强的等离子体效应，表面光场测量或不CND固定使用高光谱成像系统作为比较，和半解析模型进行定量分析的平面波照明下的表面等离子体产生。荧光和表面反射光强度增强被证明是纳米缝宽度的函数，并且在100 nm纳米缝宽度处最大化。在纳米缝区域的表面等离子体激子耦合的CND的分析表明，增强主要是由于等离子体激元光捕获增加的电磁场和等离子体激元诱导的共振能量转移。这项研究表明，将CND在等离子体纳米缝可以提供一个大大增强的基于CND的光电发射系统的光学应用。
Carbon nanodots (CNDs) are featured with a wide range of light absorption and excitation-dependent fluorescence. The emission enhancement of CNDs is of great interest for the development of nanophotonics. Although the phenomenon of plasmon-enhanced fluorescence for quantum dots and molecular dyes has been well investigated, rarely has it been reported for CNDs. In this work, a series of plasmonic nanoslit designs were fabricated and utilized for immobilization of CNDs in nanoslits and examination of the best match for plasmonic fluorescence enhancement of CNDs. In concert, to better understand the plasmonic effect on the enhancement, the surface optical field is measured with or without CND immobilization using a hyperspectral imaging system as a comparison, and a semianalytical model is conducted for a quantitative analysis of surface plasmon generation under the plane-wave illumination. Both the fluorescence and surface reflection light intensity enhancement are demonstrated as a function of nanoslit width and are maximized at the 100 nm nanoslit width. The analysis of surface plasmon-exciton coupling of CNDs in the nanoslit area suggests that the enhancement is primarily due to plasmonic light trapping for increased electromagnetic field and plasmon-induced resonance energy transfer. This study suggests that incorporating CNDs in the plasmonic nanoslits may provide a largely enhanced CND-based photoemission system for optical applications.