Surface Enhanced Raman Spectroscopy for Monitoring Lactate and Glucose

摘要

The development of a robust, portable, and simple biomedical device for the monitoring of glucose, lactate and other metabolites of interest is of great practical importance to routine treatment of diabetes and to the evaluation of individuals under high-stress situations, e.g. warfighters and astronauts. Raman spectroscopy is a powerful analytical tool that permits the unambiguous identification of molecules based on their unique vibrational modes. This spectral fingerprinting of molecules is well suited to multi- analyte detection without cumbersome sample preparation or separation. The Surface Enhanced Raman Scattering (SERS) phenomenon increases by up to a trillion fold the Raman signal from molecules near gold and silver nanoscale materials. We have shown that the incorporation of chemically tailored coatings on SERS active surfaces may serve as a partitioning layer, selectively concentrating the molecules of interest near the surface, thus simultaneously increasing target signal and decreasing the noise signal from interferants even with very low power (approximately 1mW) lasers. We have successfully developed and tested these SERS active substrates in vitro and in vivo in the subcutaneous space of a rat. Work continues in rat models of hyperglycemia and hypedactatemia.