Nanoplasmonic Probes of Catalytic Reactions

Abstract

Optical probes of heterogeneous catalytic reactions can be valuable tools for optimization and process control because they can operate under realistic conditions, but often probes lack sensitivity. We have developed a plasmonic sensing method for such reactions based on arrays of nanofabricated gold disks, covered by a thin (approximately 10 nanometer) coating (catalyst support) on which the catalyst nanoparticles are deposited. The sensing particles monitor changes in surface coverage of reactants during catalytic reaction through peak shifts in the optical extinction spectrum. Sensitivities to below 10(-3) monolayers are estimated. The capacity of the method is demonstrated for three catalytic reactions, CO and H2 oxidation on Pt, and NO(x) conversion to N2 on Pt/BaO.

Unraveling the Evolution and Nature of the Plasmons in (Au Core)–(Ag Shell) Nanorods

“…In addition, Au and Ag nanostructures are relatively stable in ambient environments. They have, therefore, been intensively studied from the perspectives of both fundamental sciences [1][2][3] and potential applications in optics, [4][5][6] sensing, [7][8][9][10] imaging, [ 11 , 12 ] information processing, [ 13 ] photothermal therapeutics, [ 11 , 12 ] solar energy harvesting, [ 14 , 15 ] and photocatalysis. [ 16 , 17 ] Gold nanocrystals, especially Au nanorods, have been widely used as detection agents for analytical and biochemical applications as well as photothermal therapy, [ 11 , 12 ] owing to their chemical stability, synthetically tunable plasmon resonance bands within the visible and near-infrared spectral regions, and facile surface functionalization using thiol-containing molecules.…”

Visualizing hybridized quantum plasmons in coupled nanowires: From classical to tunneling regime

“…1 The localized surface plasmon resonances sustained by metallic nanoparticles 2 have found widespread use in applications ranging from molecular spectroscopy 3 and chemical sensing, 4 to photocatalysis 5 and photovoltaics. 6 Applications of plasmons in next generation nanoelectronics 7 and quantum information technology 8,9 have also been envisioned.…”

Refractometric biosensing based on optical phase flips in sparse and short-range-ordered nanoplasmonic layers

“…[1][2][3][4] Plasmons in metal nanoparticles can be used as transducers of biological and chemical interactions because the plasmon strongly couples to light and because its particle-specific resonance wavelength shifts if the concentration, composition or conformation of molecules changes within nanometric distances from the particle surface. [1][2][3][4] Since the first report of an LSPR red-shift induced by molecular adsorption by Englebienne 5 in 1998, colorimetric detection using classical optical spectroscopy methods has been the most popular transduction methodology. However, it has recently been proposed that the phase information contained in light scattered or reflected from nanoparticles excited at resonance could be used to implement alternative and even more effective LSPR sensing schemes.…”