Title :
Electron irradiation effects on nanocrystal quantum dots used in bio-sensing applications
Author :
Leon, R. ; Nadeau, J. ; Evans, K. ; Paskova, T. ; Monemar, B.
Author_Institution :
Jet Propulsion Lab., California Inst. of Technol., Pasadena, CA, USA
Abstract :
Effects of low energy electron irradiation (5-30 keV) on some of the optical properties of CdSe nanocrystals are examined. Degradation in luminescence intensities are measured and compared for inorganic nanocrystals coated in trioctylphosphine oxide (TOPO) and biologically compatible CdSe nanocrystals coated in mercaptoacetic acid (MAA), as well as CdSe-MAA nanocrystals conjugated with the protein Streptavidin. Electron beam effects are investigated using the technique of cathodoluminescence, which is seen to induce significant degradation in nanocrystal related fluorescence in all nanocrystals. Varying beam energy and sample temperatures showed faster degradation at cryogenic temperatures and a higher susceptibility to low beam energies in protein conjugated nanocrystals.
Keywords :
biosensors; cadmium compounds; cathodoluminescence; cryogenics; electron beam effects; nanostructured materials; nanotechnology; semiconductor quantum dots; CdSe; CdSe-MAA nanocrystals; bio-sensing applications; biologically compatible CdSe nanocrystal; biophysics; cathodoluminescence; cryogenic temperatures; degradation; higher susceptibility; inorganic nanocrystals; low energy electron irradiation effects; luminescence intensities; mercaptoacetic acid; nanocrystal quantum dots; nanotechnology; optical properties; protein conjugated nanocrystals; protein fluorescence; semiconductor nanocrystals; trioctylphosphine oxide; Biomedical optical imaging; Degradation; Electron beams; Electron optics; Fluorescence; Luminescence; Nanocrystals; Proteins; Quantum dots; Temperature;
Journal_Title :
Nuclear Science, IEEE Transactions on
DOI :
10.1109/TNS.2004.839197
