title: Metal-enhanced fluorescence based excitation volumetric effect of plasmon-enhanced singlet oxygen and super oxide generation.
abstract: In this contribution we show that the Metal-Enhanced Fluorescence (MEF) Excitation Volumetric Effect (EVE), has a profound effect on the formation of Reactive Oxygen Species (ROS), such as singlet oxygen ((1)O2) and superoxide anion radical (O2(-)*), when sensitizers are placed in close proximity to plasmon supporting nanoparticulate substrates. In particular, when the singlet oxygen sensitizer rose bengal is placed on a SiFs surface, i.e. on a silver island film, the (1)O2 response to power is non-linear, and at 100 mW excitation power (535 nm) it is about 5 times higher, as compared to glass control samples, measured with the commercially available (1)O2 probe Sensor Green™. We also report a similar power dependence of superoxide generation for acridine on SiFs surfaces, but using the dihydroethidium O2(-)* probe (DHE). Our findings are consistent with our previously postulated Metal-Enhanced Fluorescence (MEF) and EVE models.
authors.affiliation: Institute of Fluorescence and Department of Chemistry & Biochemistry, The Columbus Center, University of Maryland Baltimore County, 701 East Pratt Street, Baltimore, MD 21202, USA. jan.karolin@gmail.com chrisgeddes72@gmail.com geddes@umbc.edu.
authors.forename: Jan
authors.initials: J
authors.lastname: Karolin
authors.forename: Chris D
authors.initials: CD
authors.lastname: Geddes
mesh_terms: D000166:Acridines / Q000737:chemistry; D004996:Ethidium / Q000031:analogs & derivatives / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D026082:Singlet Oxygen / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013481:Superoxides / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D000166:Acridines; D005456:Fluorescent Dyes; D008670:Metals; C067883:dihydroethidium; D013481:Superoxides; D026082:Singlet Oxygen; D004996:Ethidium