Surface-Enhanced Detection of Molecular and Biomolecular Species

This Phase I STTR will demonstrate the feasibility of near-infrared (near-IR) excited surface-enhanced Raman optical activity (SEROA) as a sensitive new probe of biological molecules and trace chiral materials. The research will use nanoshells as fabricated and optimized at Rice University as a newly developed, tunable, highly-uniform, SERS substrates for chiral molecules and bio-molecules. The feasibility of SEROA using a standard ChiralRAMAN ROA spectrometer from BioTools, Inc. with 532 nm excitation will be determined using commercially available SERS substrates. The project continues with the assembly and testing of a near-IR 785-nm laser version of the ChiralRAMAN spectrometer. The new 785-nm ROA instrument will then be tested in three ways. 1) Its performance as a near-IR excited Raman spectrometer will be compared to the Raman performance of the 532-nm ChiralRAMAN spectrometer. 2) Its performance will next be compared to the near-IR Raman spectrometer currently operating at Rice University for which SERS measurements with tuned nanoshells have been carried out. 3) Finally, its performance as the world's first near-IR ROA spectrometer will be tested with standard liquid samples of chiral terpene molecules. From these comparisons a quantitative prognosis for developing a near-IR SEROA spectrometer using chiral tuned-nanoshells will be established.