Developing Reusable SERS Substrates with High Signal Enhancement and Low Inherent Background based on Scalable Ultrafast Laser-Hydrothermal Hybrid Method

This proposal addresses probably the most critical issue for surface-enhanced Raman scattering (SERS) in real-world applications, i.e., the lack of commercially available robust SERS active substrates that can simultaneously provide a high SERS enhancement and an inherent low background signature. AlchLight is an established Army SBIR-II contractor. Founding members of AlchLight invented a scalable laser-chemical hybrid technology that turns regular titanium (Ti) surfaces to hierarchical micro-/nanostructured TiO2 with an exceedingly increased surface area and an unparallel strong photocatalytic effect. By adding additional Ag nanoparticles, a dramatic local-field enhancement can be achieved through plasmonic effects. This multipronged approach will allow AlchLight to produce a SERS substrate that will yield a highly uniform and reproducible SERS enhancement (>109) and more importantly, the photocatalytic TiO2/Ag system can degrade the traced molecules adsorbed on surface under light irradiation and recycle the SERS substrate and guarantee the inherent low background signature. The successful completion of this project will lead to a robust and advanced SERS technique for real-world applications. Furthermore, rapid fabrication of the developed SERS substrate is enabled by the world-first femtosecond laser Nano-to-Meter surface functionalization workstation developed by AlchLight.