Ag Nanowire-Ag Nanoparticle Hybrids for the Highly Enhanced Fluorescene Detection of Protoporphyrin IX Based on Surface Plasmon-Enhanced Fluorescence

In this study, we developed an approach to fabricate novel 1D Ag NWs-Ag NPs hybrid substrate for enhanced fluorescene detection of protoporphyrin IX (PpIX) based on surface plasmon-enhanced fluorescence. The Ag NWs-Ag NPs hybrid was synthesized by combining the hydrothermal method and self-assembly method with the asisstance of polyvinylpyrrolidone (PVP). When the Ag NWs-Ag NPs hybrid was deposited on the glass substrate and employed as active substrate to detect PpIX, the fluorescence intensity of PpIX was enhanced greatly due to the coupling effect of localized surface plasmon-localized surface plasmon (LSP-LSP) and localized surface plasmon-surface plasmon propagation (LSP-SPP) which induced great enhancement of the electromagnetic field. Furthermore, the enhancement effect was approximately linear when the concentration of PpIX was ranged from 1x10(-7) mol/L to 2x10(-5) mol/L, and the photobleaching phenomenon of PpIX was reduced greatly, indicating that the fabricated Ag NWs-Ag NPs hybrid substrate had well performance for PpIX imaging. This work provides an effective approach to prepare highly sensitive and stable fluorescence enhancement substrate, and has great potential application in fluorescence imaging.