Spectral reflectance biosensing for label-free and dynamic detection of protein, DNA and viruses

Note: Pizza served at 11:45
Speaker: Bennett Goldberg, Boston University

When: January 22, 2010 (Fri), 12:00PM to 01:00PM (add to my calendar)
Hosted by: Claudio Chamon, Ophelia Tsui

This event is part of the Biophysics/Condensed Matter Seminar Series.

Abstract:
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HE development of compact, rapid, multiplexed and high-throughput molecular recognition platforms hold the promise of revolutionizing personalized medicine, point-of-care diagnostics and monitoring, and global health delivery in resource-limited settings. The approach of direct monitoring of primary molecular binding interactions obviates the need for labeling or secondary reactants and thus has the greatest potential for broad applications. Spectral Reflectance Biosensing (SRB) is a simple interferometric technique that monitors the optical phase difference resulting from accumulated biomolecular mass on the surface of a chip. We have demonstrated quantitative and dynamic measurements with ~3 pg/mm2 sensitivity for molecular interactions, including protein-protein binding, DNA-protein binding, simultaneous detection of antigens and antibodies, and DNA hybridization kinetics.
SRB is a common path optical interferometer and so is completely insensitive to variations in concentration of analyte material or temperature. Also, SRB is independent of surface conformation of the molecules because it does not rely on an evanescent wave interaction like Surface Plasmon Resonance. Importantly, this advantage allows utilization of unique polymeric coatings for immobilization and surface binding which results in versatile and high-density arrays. In addition to high-sensitivity, SRB has a very large field-of-view so the number of spots can be used alternatively to optimize sensitivity and signal-to-noise or increase throughput. SRB can thus measure binding signals over hundreds of different conditions simultaneously, and be easily expanded to suit the needs of various screening protocols. Recently, we have simplified the instrumentation by utilizing discrete LED sources instead of a tunable laser, improved spatial resolutions and demonstrated capability in single pathogen (virus) detection.
References

[1]I. E. Ozkumur J.W. Needham, D. A. Bergstein, R. Gonzalez, M. Cabodi, J. M. Gershoni, B. B. Goldberg, and M. S. Ünlü, “Label-free and dynamic detection of biomolecular interactions for high-throughput microarray applications,” PNAS, Vol. 105, pp. 7988–7992 (2008)
[2]I. E. Ozkumur, A. Yalcin, M. Cretich, C. Lopez, D. A. Bergstein, B. B. Goldberg, M. Chiari, M. S.Ünlü, “Quantification of DNA and protein adsorption by optical phase shift ,” Biosensors and Bioelectronics, Vol. 25, pp. 167-172, (2009).
[3]D. A. Bergstein, I. E. Ozkumur, A. C. Wu, A. Yalcin, J. R. Colson, J. W. Needham, R. J. Irani, J. M. Gershoni, B. B. Goldberg, C. DeLisi, M. F. Ruane, M. S. Ünlü, “Resonant Cavity Imaging: A Means Toward High-Throughput Label-Free Protein Detection,” IEEE J. Select. Topics in Quantum Electron., Special Issue on Biophotonics, vol. 14, no. 1, pp. 131-139, (2008)
[4]I. E. Ozkumur, et al., “Label-free microarray imaging for direct detection of DNA hybridization and single-nucleotide mismatches,” Biosensors and Bioelectronics, accepted for publication (2010)