Enhancing FRET Efficiency of Precisely Spaced Fluorescent Molecules Using Surface Plasmons

This project explores using surface plasmon waves excited on nanopatterned gold surfaces to enhance the efficiency of Förster Resonance Energy Transfer (FRET) between donor and acceptor fluorescent molecules. Surface plasmons are known to enhance fluorescence efficiency by altering the local density of optical states. Gold nanogratings were fabricated using a template stripping method. Following fabrication, the nanogratings are characterized. First we measured the topology using an atomic force microscope to ensure proper transferring of the nanopattern. Then we used white light spectroscopy to map out varying wavelengths of surface plasmons as a function of the angle of incident light. Following characterization, DNA with attached donor and acceptor fluorescent molecules were then deposited on viable samples. The DNA ensures the precise distance between the fluorescent molecules can be known, both in relation to each other and to the surface of the substrates. In this talk we will discuss optimizing the distance between the molecules and the gold surface for FRET enhancement.