Purcell Factor: A Tunable Metric for Plasmon-Coupled Fluorescence Emission Enhancements in Cermet Nanocavities

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• 作者：Venkatesh Srinivasan ; Sai Sathish Ramamurthy
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：February 11, 2016
• 年：2016
• 卷：120
• 期：5
• 页码：2908-2913
• 全文大小：379K
• ISSN：1932-7455

文摘

We demonstrate an important approach to correlate Purcell factor (PF) and surface plasmon-coupled emission (SPCE) enhancements with the use of finite-difference time-domain (FDTD) simulations and time-correlated single-photon counting (TCSPC) studies of a radiating dipole in cermet nanocavities. We observed >50-fold fluorescence enhancement with high directionality and polarization of Rhodamine 6G (Rh6G) emission trapped in the nanocavity created between the titanium-based ceramic nanoparticle and metallic silver thin film. Compositional variation with hybrid nanoparticles, TiC₀N₁ (TiN), TiC_0.5N_0.5 (TiCN), and TiC₁N₀ (TiC), brought about enhanced PFs and tunable fluorescence enhancements that were used for mobile-phone-based detection of tryptophan with nanomolar sensitivity. We hope that this study opens the door to next-gen plasmonics with the ability to tune and enhance the hot-spot electromagnetic field intensity of alternative plasmonic materials, as hybrid synergy spacers in the SPCE platform.