TY - JOUR T1 - High-sensitivity molecular sensing using plasmonic nanocube chains in classical and quantum coupling regimes JF - Nano Today Y1 - 2017 A1 - Hooshmand, Nasrin A1 - et al. KW - display ER - TY - JOUR T1 - Hyperoxia Induces Intracellular Acidification in Neonatal Mouse Lung Fibroblasts: Real-Time Investigation Using Plasmonically Enhanced Raman Spectroscopy JF - Journal of the American Chemical Society Y1 - 2016 A1 - Panikkanvalappil, Sajanlal R. A1 - James, Masheika A1 - Hira, Steven M A1 - Mobley, James A1 - Jilling, Tamas A1 - Ambalavanan, Namasivayam A1 - El-Sayed, Mostafa A. VL - 138 ER - TY - JOUR T1 - High-temperature surface enhanced Raman spectroscopy for in situ study of solid oxide fuel cell materials JF - Energy & Environmental Science Y1 - 2014 A1 - Li, Xiaxi A1 - Lee, Jung-Pil A1 - Blinn, Kevin S A1 - Chen, Dongchang A1 - Yoo, Seungmin A1 - Kang, Bin A1 - Bottomley, Lawrence A A1 - El-Sayed, Mostafa A. A1 - Park, Soojin A1 - Liu, Meilin VL - 7 ER - TY - JOUR T1 - Hollow and Solid Metallic Nanoparticles in Sensing and in Nanocatalysis JF - Chemistry of Materials Y1 - 2014 A1 - Mahmoud, M A A1 - O'Neil, D. A1 - El-Sayed, M. A. KW - n/a VL - 26 SN - 0897-4756 N1 - Mahmoud, Mahmoud A. O'Neil, Daniel El-Sayed, Mostafa A.Si J1 - Chem Mater M3 - 10.1021/cm4020892 ER - TY - JOUR T1 - High-Frequency Mechanical Stirring Initiates Anisotropic Growth of Seeds Requisite for Synthesis of Asymmetric Metallic Nanoparticles like Silver Nanorods JF - Nano Letters Y1 - 2013 A1 - Mahmoud, M A A1 - El-Sayed, M. A. A1 - Gao, J. P. A1 - Landman, U. VL - 13 SN - 1530-6984 N1 - Mahmoud, Mahmoud A. El-Sayed, Mostafa A. Gao, Jianping Landman, Uzi J1 - Nano Lett. M3 - 10.1021/nl402305n ER - TY - JOUR T1 - Hollow and Solid Metallic Nanoparticles in Sensing and in Nanocatalysis JF - Chemistry of Materials Y1 - 2013 A1 - Mahmoud, Mahmoud A. A1 - O’Neil, Daniel A1 - El-Sayed, Mostafa A. VL - 26 SN - 0897-4756 J1 - Chem Mater ER - TY - JOUR T1 - Hollow gold nanorectangles: The roles of polarization and substrate JF - Journal of Chemical Physics Y1 - 2013 A1 - Near, R. D. A1 - El-Sayed, M. A. VL - 139 SN - 0021-9606 N1 - Near, Rachel D. El-Sayed, Mostafa A. J1 - J. Chem. Phys. M3 - 10.1063/1.4812931 ER - TY - JOUR T1 - Hot electron relaxation dynamics of gold nanoparticles embedded in MgSO4 powder compared to solution: The effect of the surrounding medium JF - Journal of Physical Chemistry B Y1 - 2002 A1 - Link, Stephan A1 - Furube, A. A1 - Mohamed, MB A1 - Asahi, T. A1 - Masuhara, H. A1 - El-Sayed, Mostafa A AB - To test the influence of the surrounding medium on the relaxation dynamics of the plasmon band bleach recovery of gold nanoparticles after excitation with femtosecond laser pulses, we embedded 14.5 and 12.1 nm colloidal gold nanoparticles (synthesized electrochemically) in MgSO4 powder and investigated these samples by femtosecond diffuse reflectance spectroscopy. By measuring the relaxation dynamics over a wide range of excitation energies, we found that the fast decay component is slower by about a factor of 2 for the particles in the MgSO4 powder compared to those in solution while no significant change in the slow decay component is observed. In agreement with this observation, we found that adding solvent to the particles embedded in the powder caused a decrease in the relaxation time from about 10 ps to 5 ps for the fast decay component. This leads to the conclusion that the electron-phonon relaxation in these gold nanoparticles depends on the chemical nature and/or physical phase (solid vs solution) of the surrounding medium. A discussion of this in terms of the type of phonon involved, and the nature of the electron-phonon and phonon-phonon relaxation processes is discussed. To our knowledge, this also presents the first time that a transient bleach could be observed by diffuse reflectance spectroscopy. VL - 106 SN - 1520-6106 N1 - Link, S Furube, A Mohamed, MB Asahi, T Masuhara, H El-Sayed, MA M3 - 10.1021/jp013311k ER - TY - JOUR T1 - Hot electron and phonon dynamics of gold nanoparticles embedded in a gel matrix JF - Chemical Physics Letters Y1 - 2001 A1 - Mohamed, MB A1 - Ahmadi, Temer S. A1 - Link, Stephan A1 - Braun, Markus A1 - El-Sayed, Mostafa A AB - Using pump-probe technique, the dynamics of the hot carriers in metallic nanodots induced by femtosecond laser pulses are investigated in gold nanoparticles embedded in hydrogel and in organic gel and compared to that in aqueous solution. We found that changing the surrounding matrix from aqueous solution to hydrogel and then to organic gel leads to a large increase in the relaxation time of both the electron-phonon (e-ph) and the phonon-phonon (ph-ph) coupling. Furthermore, the ph-ph relaxation time becomes sensitive to the type of the organic solvent trapped in the gel network. This indicates that the relaxation dynamics depend on the thermal conductivity, chemical structure and the molecular dynamics of the surrounding medium. (C) 2001 Elsevier Science BN. All rights reserved. VL - 343 SN - 0009-2614 N1 - Mohamed, MB Ahmadi, TS Link, S Braun, M El-Sayed, MA M3 - 10.1016/s0009-2614(01)00653-4 ER - TY - JOUR T1 - High-density femtosecond transient absorption spectroscopy of semiconductor nanoparticles. A tool to investigate surface quality JF - Pure and Applied Chemistry Y1 - 2000 A1 - Burda, Clemens A1 - El-Sayed, Mostafa A AB - At the high laser excitation intensities used in our experiments, more than 50 electron-hole pairs are formed in colloidal semiconductor nanoparticles used in our studies. At this density of charge carriers, new transient absorptions are observed in the femtosecond transient spectra in the 450 to 700 nm region with unresolved fast rise (<100 fs) and two decay components of 660 fs and >150 ps. The absorption at 510 nm could be quenched with the adsorption of electron accepters (e.g., benzoquinone, 1,2-naphthoquinone), whereas the low-energy transient absorption was not affected. For CdS NPs, we found that passivation eliminated most of the transient absorption. The transient absorptions are thus proposed to result from either trap-state absorption, trapped dimers (or complexes) and/or Stark-shifted exciton absorption resulting from surface electric field of the uncompensated trapped electron-hole pairs. All these possibilities require effective surface trapping at these high levels of excitation. VL - 72 SN - 0033-4545 N1 - Burda, C El-Sayed, MA1st IUPAC Workshop on Advanced Material (WAM1)Jul 14-18, 1999Hong kong, peoples r chinaIupac M3 - 10.1351/pac200072010165 ER - TY - JOUR T1 - How does a gold nanorod melt? JF - Journal of Physical Chemistry B Y1 - 2000 A1 - Link, Stephan A1 - Wang, Z.L. A1 - El-Sayed, Mostafa A AB - Structural transformation of gold nanorods are investigated by high-resolution transmission electron microscopy after they have been exposed to low-energy femtosecond and nanosecond laser pulses in colloidal solution. The pulse energies were below the gold nanorod melting threshold, but allowed early stage shape transformation processes, It is found that while the as-prepared nanorods are defect-free, laser-irradiation induces point and line defects. The defects are dominated by (multiple) twins and stacking faults (planar defects), which are the precursor that drives the nanorods to convert their {110} facets into the more stable {100} and {111} facets and hence minimize their surface energy. These observations suggest that short-laser pulsed photothermal melting begins with the creation of defects inside the nanorods followed by surface reconstruction and diffusion, in contrast with the thermal melting of the rods or the bulk material, where the melting starts at the surface. VL - 104 SN - 1089-5647 N1 - Link, S Wang, ZL El-Sayed, MA M3 - 10.1021/jp0011701 ER - TY - JOUR T1 - How long does it take to melt a gold nanorod? A femtosecond pump-probe absorption spectroscopic study JF - Chemical Physics Letters Y1 - 1999 A1 - Link, Stephan A1 - Burda, Clemens A1 - Nikoobakht, Babak A1 - El-Sayed, Mostafa A AB - Using pump-probe femtosecond transient absorption spectroscopy, we determined the rate of the bleach of absorption around 700-800 nm due to the longitudinal surface plasmon band of gold nanorods. Using TEM of the spotted, completely irradiated solutions suggest that the dominant products of the photothermal conformation of the rods are spheres of comparable volume. This lead to the conclusion that the melting of the rods is at least 30-35 ps, independent of the power used (5-20 mu J) or the nanorod aspect ratio (1.9-3.7). (C) 1999 Elsevier Science B.V. All rights reserved. VL - 315 SN - 0009-2614 N1 - Link, S Burda, C Nikoobakht, B El-Sayed, MA M3 - 10.1016/s0009-2614(99)01214-2 ER - TY - JOUR T1 - Homogeneous Line Width of the Different Vibronic Bands of Retinal Absorption in Bacteriorhodopsin by the Hole-Burning Technique JF - The Journal of Physical Chemistry Y1 - 1996 A1 - Kamalov, Valey F. A1 - Masciangioli, Tina M. A1 - El-Sayed, Mostafa A AB - Using the hole-burning technique, resolved vibrational structure was observed in the retinal absorption spectrum of bacteriorhodopsin (bR) in poly(vinyl alcohol) (PVA) film at 10 K with 556 and 632 nm irradiation. The homogeneous line widths of v = 1 and v = 2 vibronic bands are estimated from the deconvolution of the observed spectrum. The absorption maximum is found to shift by 100?200 cm-1 by using the two excitation wavelengths; resulting from partial site selection due to the contribution of inhomogeneous broadening. The hole width produced by excitation near the zero-phonon band is found to be ?1250 cm-1, which corresponds to a homogeneous width of ?600 cm-1, and the low limit of dephasing time can be estimated as 20 fs. This width is found to be independent of the vibronic band observed.Using the hole-burning technique, resolved vibrational structure was observed in the retinal absorption spectrum of bacteriorhodopsin (bR) in poly(vinyl alcohol) (PVA) film at 10 K with 556 and 632 nm irradiation. The homogeneous line widths of v = 1 and v = 2 vibronic bands are estimated from the deconvolution of the observed spectrum. The absorption maximum is found to shift by 100?200 cm-1 by using the two excitation wavelengths; resulting from partial site selection due to the contribution of inhomogeneous broadening. The hole width produced by excitation near the zero-phonon band is found to be ?1250 cm-1, which corresponds to a homogeneous width of ?600 cm-1, and the low limit of dephasing time can be estimated as 20 fs. This width is found to be independent of the vibronic band observed. PB - American Chemical Society VL - 100 SN - 0022-3654 UR - http://dx.doi.org/10.1021/jp952971k CP - 8 N1 - doi: 10.1021/jp952971k J1 - J. Phys. Chem. M3 - doi: 10.1021/jp952971k ER -