In NanoBioPhotonics lab, we employ nanophotonics tools to overcome the existing limitations in fluorescence spectroscopy and microscopy techniques. Particularly we are using the localized surface plasmon resonance (LSPR) of metal nanostructures (Au, Ag and Al) to overcome the diffraction limit in single molecule fluorescence detection. The LSPR of these metal nanostructures focuses and localizes light far below the limit imposed by the diffraction of light, creating an intense electromagnetic field known as a hotspot. When an emitter is placed in the hotspot created by the metal nanostructures, the intense electromagnetic field increases the excitation and emission rate of the emitter, leading to a significant enhancement of the fluorescence signal. Additionally, the smaller observation volume offered by the hotspot also enables single molecule measurements at biologically relevant concentrations.

By improving the fluorescence signal, we are aiming to acquire data at a faster speed and with a higher temporal resolution in single molecule fluorescence measurements. This will enable us for a better understanding of the structure-function relationship of important biomolecules such as proteins, DNA, and RNA.  We use single molecule Förster resonance energy transfer(smFRET) to study the structure and interaction dynamics of the biomolecules. FRET is highly sensitive to changes in distance in the nanometric scale and allows for a precise measurement of structural changes in biomolecules. We are particularly interested in studying the DNA-protein interactions, which have potential applications in anticancer and antiviral therapies.