Event Information
Advanced Biophotonics: From Nanosensors to Biochips
- Abstract:
- This lecture provides an overview of the research activities in our laboratory related to the development and application of advanced biophotonics, molecular spectroscopy, nanosensors and biochips for chemical, biological and medical sensing. The first research area involves the development of sensors based on metallic nanoprobes that can produce the surface-enhanced Raman scattering (SERS) effect for ultrasensitive biochemical analysis. The intensity of the normally weak Raman scattering process is increased by factors as large as 106-1015 for compounds adsorbed onto SERS-active metallic nanostructures, allowing for ultratrace detection. The SERS nanoprobe technology has been incorporated in fiberoptic probe designs for remote analysis and in microarray formats for ultra-high throughput multiplex gene diagnostics (HIV, cancer genes).
Combining the exquisite specificity of biological recognition probes and the excellent sensitivity of laser-based optical detection, biosensors are capable of detecting and differentiating bio/chemical constituents of complex systems in order to provide unambiguous identification and accurate quantitation, and open new horizons for chemical and biological sensing. This area of research involves the development of nanosensors and nanoprobes for in vivo analysis of a single living cell [molecular markers, apoptosis following photodynamic (PDT) cancer treatment]. Such nanosensors could be used to study in situ intracellular signaling processes and to study gene expression and molecular processes within sub-compartments inside individual living cells.
In another application of biosensors, we have developed a novel integrated Multi-functional Biochip (MFB) which allows simultaneous detection of several disease end-points using different bioreceptors (DNA, antibodies, enzymes, cellular probes) on a single biochip system. An important element in the development of the MFB involves the design and development of an integrated circuit electro-optic system for the microchip detection elements based on the complementary metal oxide silicon (CMOS) technology. The biochip has been developed to detect the gene fragments of Tuberculosis and the HIV gene system as well as the p53 and FHIT proteins. The biochip could be used to diagnose genetic susceptibility and diseases, or to monitor exposure to biological pathogens.
For in vivo medical diagnostics, we have developed an optical diagnostic procedure based on laser-induced fluorescence (LIF) for direct in vivo cancer diagnosis without requiring biopsy. LIF measurements were conducted during routine gastrointestinal (GI) endoscopy examinations of patients. The fiberoptic probe was inserted into the biopsy channel of an endoscope and lightly touched the surface of the tissue being monitored. The LIF measurement was completed in approximately 0.6 second for each tissue site. The results of this LIF approach were compared with histopathology results of the biopsy samples and indicated excellent agreement (98%) in the classification of normal tissue and malignant tumors of GI cancer in clinical studies involving over 200 patients.
Host: David Beratan
Departmental Seminar