Research Projects

Surface enhanced Raman scattering (SERS) is a powerful method for ultrasensitive detection of trace pollutants. It uses electromagnetic and chemical charge transfer mechanisms to extract molecular fingerprint information. Advances in SERS substrate fabrication have shown rapid, on-line, and quantitative detection of multiple analyte molecules. This proposal aims to modulate the coffee ring effects to enhance the uniformity of SERS hotspots and its enhancement factor and limit of detection for various analyte molecules. The proposal focuses on optimizing the coffee ring patterns of colloidal solutions of plasmonic nanoparticles over blue luminescent and hydrophobic upconverting quantum dots. The fabrication of quantum dot-mediated dual-plasmonic composite-based SERS substrates will enhance the SERS signal by using only one excitation, indirectly exciting surface plasmons of other types of nanoparticles via up-conversion processes offered by quantum dots. This work combines coffee ring effects, up-conversion luminescence, and enhanced SERS sensing applications for universal detection of various analytes and contaminants.