Small-Molecule, Label-Free Analyte Detection Using Fluorescence Resonance Energy Transfer (FRET)

PI: Allison Dennis, Catherine Klapperich, James Galagan, Mark Grinstaff

In the Dennis Lab, we specialize in fluorescent biosensing approaches using fluorescence resonance energy transfer (FRET) as a way to generate two-color, ratiometric outputs in response to the presence or absence of a physiologically relevant molecule like a hormone or environmental cues, such as pH. For FRET-based biosensing, the emission intensity of the donor fluorophore is quenched and the intensity of the acceptor fluorophore is enhanced if the two fluorescent agents are in close proximity, i.e. 1-10 nm apart. The association and dissociation of various biomolecules attached to the fluorophores in response to the analyte changes the distance between the donor and acceptor, thereby changing the intensity of the two emitted colors. The ratio of the intensity of these two colors, i.e. the intensity of the acceptor emission to the intensity of the donor emission, is a robust output that is consistent regardless of sensor concentration or other environmental factors that can confound single-color sensors. We are using this sensing mechanism to detect hormone concentrations in physiological samples.

Funding Agencies: DARPA