Plasmonic Current for Monitoring Excited-State Kinetics

Excited-state reactions are an essential phenomenon in many biological, chemical, and physical processes. However, current methods to study these excited-state reactions often involve large, expensive and elaborate instrumentation. Here, we investigate the reaction kinetics of a few well-known classical fluorescent-based processes through a novel approach called, <i>plasmonic current</i>. Plasmonic current operates when a fluorophore near-to a metallic nanoparticle island film can non-radiatively transfer its energy to the surface of the metal, inducing electron hopping across the metal and subsequently generating current. The magnitude of the current is influenced by the type of metal, spacing of the metal nanoparticles, spectral properties of the fluorophore and the distance of the fluorophore from the metal. Studying reaction kinetics through plasmonic current can potentially simplify the process and open doors to analyzing various other reactions that would otherwise involve complex instrumentation and moreover experimental geometries. Some applications of this technology include solar energy conversion, biological sensing, and chemical sensing, to name but just a few.