SCANNING PHOTOIONIZATION IMAGING MICROSCOPY AND ULTRA KINETICS OF PLASMONIC NANOMATERIALS
Abstract
We will take advantage of ultrafast laser microscopy tools to elucidate the polarization, intensity and wavelength-dependent plasmonic photoemission properties of “designer” nanostructures (e.g., Au/Ag nanoshells, nanobowties, nanorods, nanostars, etc), for which the multiphoton nature of the photoemission process (ISPIM ? E8) translates into > 10^10 fold increase in SPIM signals, and therefore exquisite sensitivity to local E field enhancements arising from the nanoparticle architecture. We will implement 3D electron velocity map imaging (3D-VMI) methods for characterizing the full vector momentum and kinetic energy distributions of the photoelectrons ejected from a single nanostructure as well as incorporate ultrafast time resolved (1+1’) pump-probe capabilities for studying hot electron photoemission/relaxation dynamics. This will permit us to explore electron photoemission propensities for isolated, size- and shape-controlled nanostructures, combining SPIM microscopy with AFM/TEM/SEM methods on spatially registered samples for fully correlated characterization of optical, physical and plasmonic properties at the single nanoparticle level.We will initiate a new collaboration with colleagues at Wright Patt AFB in the design, synthesis and characterization of single molecule RNA “riboswitch” biosensors using single molecule fluorescence detection/Forster Resonance Energy Transfer (smFRET) methods. This approach is based on ideas highly evolutionarily refined by Nature for cellular gene regulation, exploiting conformationally flexible RNA strands as versatile biosensors for specific molecular targets. Specifically, RNA oligomers (40-mers) can be systematically selected from a combinatorial library of 1013-1015 sequences for enhanced binding sensitivity toward a desired target metabolite (e.g., cortisol or TNT), that in turn can induce conformational folding of the RNA and be detected via advanced smFRET, single photon counting, and confocal LIF microscopy imaging.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2021
- Source ID
- FA95502010213
Entities
People
- David J. Nesbitt
Organizations
- Air Force Office of Scientific Research
- Regents of the University of Colorado
- United States Air Force