Surface-Enhanced Detection of Molecular and Biomolecular Species

This Phase II STTR project continues the development of two prior successful Phase I STTR projects aimed at developing surface-enhance Raman optical activity (ROA) on near-infrared tuned gold-coated nanoshells for the detection of chiral molecules, biological molecules and higher biological structures and organisms for applications in the areas of biological research, pharmaceutical development and bio-defense technology. The principal Phase I outcomes of this project were 1) the construction of the first ROA spectrometer outside the visible region that has the advantages of low fluorescence and exceptional sensitivity to near-IR tuned gold-coated nanoshells, and 2) the fabrication of both solution and solid films of nanoshells with the chiral molecule S-phenyethylenethiol (S-PET) attached. Phase II research will consist of the optimization of SERS/SEROA sampling to overcome aggregation with time of the nanoshell samples in solution phase and spectral variations associated with changing the location of laser focus on the nanoshell film samples. New chiral nanoshells will be fabricated using a variety of attachment mechanisms for samples of increasing biological significance and complexity. A more compact version of the near-IR SEROA spectrometer will be developed with the added capability of microscope attachment for interrogation of sample variation and uniformity of the SERS/SEROA substrates. Theoretical calculations will support the interpretation of new SEROA spectra.