Fluorescence is a dominant technology in medical testing, drug discovery, biotechnology and cellular imaging. There is demand for better fluorescent agents in terms of intensity, spectral range, functionality, photostability and phototoxicity. Recent trends in analytical and material sciences drive devices smaller and faster toward molecular level sensing. At this level, sensitive detection is a major issue.This research promises to provide nanoscale and molecular sensing with simultaneous dramatic increases in fluorescence signal to noise ratio. The sensing technology relies on the interaction of light with metallic nanoparticles such as silver and gold colloids resulting in remarkably high increases in fluorescence intensity of nearby fluorophores of up to 10 Million-fold. The research in development of nanosensors will be focused on fabrication of multifunctional composite nano-sized particles with fluorescent probes. The sensing elements will be constructed using silver and silica nanometer sized colloids combined with fluorescent probes. To demonstrate feasibility of the nanosensors, probes for pH and Ca2+ measurements will be used.Several modern optical techniques will be used to evaluate effects of fluorophore-metal surface interactions including laser scanning, two-photon excitation, and lifetime imaging microscopy. Software will be developed for rapid acquisition and image analysis of 2D and 3D nanosensors. The result of Phase I will be a basis of knowledge sufficient to permit prototype sensor fabrication and continued development in Phase II. Probe-metal colloid composites will significantly improve detection and analysis of biologically relevant analytes in samples including whole blood, saliva, and other body fluids. These novel sensors with improved intensities and photostability can be used with or without imaging optics. Due to the predicted large enhancement in fluorescence intensity, we envision the future development of field deployable biosensors to rapidly detect environmental infectious agents with sensitivity and specificity approaching if not surpassing laboratory procedures.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Small Business Innovation Research Grants (SBIR) - Phase I (R43)
Project #
5R43CA097569-02
Application #
6665118
Study Section
Special Emphasis Panel (ZRG1-SSS-6 (10))
Program Officer
Song, Min-Kyung H
Project Start
2002-09-30
Project End
2004-08-31
Budget Start
2003-09-24
Budget End
2004-08-31
Support Year
2
Fiscal Year
2003
Total Cost
$148,484
Indirect Cost
Name
Microcosm, Inc.
Department
Type
DUNS #
824609663
City
Columbia
State
MD
Country
United States
Zip Code
21045
Aslan, Kadir; Lakowicz, Joseph R; Szmacinski, Henryk et al. (2005) Enhanced ratiometric pH sensing using SNAFL-2 on silver island films: metal-enhanced fluorescence sensing. J Fluoresc 15:37-40
Asian, Kadir; Lakowicz, Joseph R; Szmacinski, Henryk et al. (2004) Metal-enhanced fluorescence solution-based sensing platform. J Fluoresc 14:677-9