@article {1653,
	title = {Gold nanomaterials as key suppliers in biological and chemical sensing, catalysis, and medicine},
	journal = {Biochimica et Biophysica Acta (BBA)-General Subjects},
	year = {2020},
	author = {Falahati, M. and Attar, F. and Sharifi, M. and Saboury, A.A. and Salihi, A. and Aziz, F.M. and Kostova, I. and Burda, C. and Priecel, P. and Lopez-Sanchez, J.A. and Laurent, S. and Hooshmand, N. and El-Sayed, M.A.}
}
@article {1658,
	title = {Observation of Photoinduced Proton Transfer between the Titania Surface and Dye Molecule},
	journal = {The Journal of Physical Chemistry C},
	year = {2020},
	author = {Nishikiori, H. and Kondo, H. and Kageshima, Y. and Hooshmand, N. and Panikkanvalappil, S. R. and Valverde-Ch{\'a}vez, D.A. and Silva, C. and El-Sayed, M.A. and Teshima,K.}
}
@article {1656,
	title = {Enhanced Electrochemical Dark-Field Scattering Modulation on Single Hybrid Core-Shell Nanostructure},
	journal = {The Journal of Physical Chemistry C},
	year = {2019},
	author = {Zhou, J. and Panikkanvalappil, S.R. and Kang, S. and Yu, S. and Zhang, S. and El-Sayed, M.A. and Tsukruk, V.V.}
}
@article {1652,
	title = {Enhancing Plasmonic{\textendash}Photonic Hybrid Cavity Modes by Coupling of Individual Plasmonic Nanoparticles},
	journal = {The Journal of Physical Chemistry C},
	year = {2019},
	author = {Zhang, S. and Panikkanvalappil, S.R. and Kang, S. and Smith, M.J. and Yu, S. and El-Sayed, M. and Tsukruk, V.V.}
}
@article {1643,
	title = {Monitoring the dynamics of hemeoxygenase-1 activation in head and neck cancer cells in real-time using plasmonically enhanced Raman spectroscopy},
	journal = {Chemical Science},
	year = {2019},
	author = {Panikkanvalappil, S. R. and Garlapati, C. and Hooshmand, N. and Aneja, R. and El-Sayed, M. A.}
}
@article {1637,
	title = {Enhancing the rate of electrochemical nitrogen reduction reaction for ammonia synthesis under ambient conditions using hollow gold nanocages},
	journal = {Nano Energy},
	year = {2018},
	keywords = {display},
	author = {M. Nazemi and Panikkanvalappil, S. R. and El-Sayed, M. A.}
}
@article {1634,
	title = {Single-Crystal Electrospun Plasmonic Perovskite Nanofibers},
	journal = {The Journal of Physical Chemistry C},
	year = {2018},
	author = {A.M. Abdellah and A. Hafez and Panikkanvalappil, S. R. and El-Sayed, M. A. and Allam, N. K.}
}
@article {1604,
	title = {Intracellular assembly of nuclear-targeted gold nanosphere enables selective plasmonic photothermal therapy of cancer by shifting their absorption wavelength toward near-infrared region},
	journal = {Bioconjugate Chemistry },
	year = {2017},
	keywords = {display},
	author = {Panikkanvalappil, Sajanlal R. and et al.}
}
@article {1629,
	title = {Advances in Nanomedicine for Head and Neck Cancer},
	journal = {Head and Neck Cancer},
	year = {2016},
	author = {Panikkanvalappil, S. R. and et al.}
}
@article {1593,
	title = { Electrically Controlled Plasmonic Behavior of Gold Nanocube@ Polyaniline Nanostructures: Transparent Plasmonic Aggregates},
	journal = {Chem. Mater.},
	year = {2016},
	author = {Jeon, J.-W. and Ledin, P. A. and Geldmeier, J. A. and Ponder, J. F. and Mahmoud, M A and El-Sayed, M. and Reynolds, J. R. and Tsukruk, V. V.}
}
@article {1590,
	title = {Elucidation of Ultraviolet RadiationInduced Cell Responses and Intracellular Biomolecular Dynamics in Mammalian Cells Using Surface-Enhanced Raman Spectroscopy},
	journal = {Chemical Science },
	year = {2016},
	author = {Panikkanvalappil, S. R. and Hira, S. M. and El-Sayed, M. A.}
}
@article {1584,
	title = {Hyperoxia Induces Intracellular Acidification in Neonatal Mouse Lung Fibroblasts: Real-Time Investigation Using Plasmonically Enhanced Raman Spectroscopy},
	journal = {Journal of the American Chemical Society},
	volume = {138},
	year = {2016},
	pages = {3779{\textendash}3788},
	author = {Panikkanvalappil, Sajanlal R. and James, Masheika and Hira, Steven M and Mobley, James and Jilling, Tamas and Ambalavanan, Namasivayam and El-Sayed, Mostafa A.}
}
@article {1588,
	title = { Large Enhancement of Circular Dichroism Using an Embossed Chiral Metamaterial},
	journal = { arXiv preprint},
	year = {2016},
	doi = {1604.05244},
	author = {Mousavi, S.; and Panikkanvalappil, S. R.; and El-Sayed, M. A.; and Eftekhar, A. A.; and Adibi, A.}
}
@article {1582,
	title = {Cytotoxic effects of cytoplasmic-targeted and nuclear-targeted gold and silver nanoparticles in HSC-3 cells{\textendash}A mechanistic study},
	journal = {Toxicology in Vitro},
	volume = {29},
	year = {2015},
	pages = {694{\textendash}705},
	author = {Lauren A. Austin and Ahmad, Samera and Kang, Bin and Rommel, Kathryn R and Mahmoud, Mahmoud and Peek, Mary E and El-Sayed, Mostafa A.}
}
@article {1574,
	title = {Near-Infrared Asymmetrical Squaraine Sensitizers for Highly Efficient Dye Sensitized Solar Cells: The Effect of π-Bridges and Anchoring Groups on Solar Cell Performance},
	journal = {Chemistry of Materials},
	volume = {27},
	year = {2015},
	pages = {2480-2487},
	doi = {10.1021/cm5045946},
	url = {http://dx.doi.org/10.1021/cm5045946},
	author = {Fadi M. Jradi and Xiongwu Kang and O{\textquoteright}Neil, Daniel and Gabriel Pajares and Yulia A. Getmanenko and Szymanski, Paul and Timothy C. Parker and El-Sayed, Mostafa A. and Seth R. Marder}
}
@article {1370,
	title = {Enhancing the Efficiency of Gold Nanoparticles Treatment of Cancer by Increasing Their Rate of Endocytosis and Cell Accumulation Using Rifampicin},
	journal = {Journal of the American Chemical Society},
	volume = {136},
	number = {12},
	year = {2014},
	pages = {4464-4467},
	isbn = {0002-7863},
	author = {Ali, Moustafa RK and Panikkanvalappil, Sajanlal R. and El-Sayed, Mostafa A.}
}
@article {1362,
	title = {High-temperature surface enhanced Raman spectroscopy for in situ study of solid oxide fuel cell materials},
	journal = {Energy \& Environmental Science},
	volume = {7},
	number = {1},
	year = {2014},
	pages = {306-310},
	author = {Li, Xiaxi and Lee, Jung-Pil and Blinn, Kevin S and Chen, Dongchang and Yoo, Seungmin and Kang, Bin and Bottomley, Lawrence A and El-Sayed, Mostafa A. and Park, Soojin and Liu, Meilin}
}
@article {1351,
	title = {Probing the unique dehydration-induced structural modifications in cancer cell DNA using surface enhanced Raman spectroscopy},
	journal = {J Am Chem Soc},
	year = {2013},
	note = {MEDLINE AN 2013442001(Journal; Article; (JOURNAL ARTICLE))},
	month = {//},
	abstract = {Conformation-induced formation of a series of unique Raman marker bands in cancer cell DNA, upon dehydration, have been probed for the first time with the use of surface enhanced Raman spectroscopy (SERS). These bands are capable of distinguishing cancer cell DNA from healthy cell DNA. For this simple and label-free DNA detection approach, we used conventional spherical silver nanoparticles, at a high concentration, without any aggregating agents, which gave highly reproducible SERS spectra of DNA separated from various human cells irrespective of their highly complex compositions and sequences. The observed phenomenon is attributed to the change in the chemical environment due to the presence of nucleobase lesions in cancer cell DNA and subsequent variation in the nearby electronic cloud during the dehydration-driven conformational changes. Detailed analysis of the SERS spectra gives important insight about the lesion-induced structural modifications upon dehydration in the cancer cell DNA. These results have widespread implications in cancer diagnostics, where SERS provides vital information about the DNA modifications in the cancer cells.[on SciFinder (R)]},
	isbn = {1520-5126},
	author = {Panikkanvalappil, Sajanlal R. and Mackey, Megan A. and El-Sayed, Mostafa A.}
}
@article {1385,
	title = {Properties of pi-Conjugated Fluorescence Polymer-Plasmonic Nanoparticles Hybrid Materials (vol 116, 13336, 2012)},
	journal = {Journal of Physical Chemistry C},
	volume = {117},
	number = {9},
	year = {2013},
	note = {Mahmoud, M. A. Poncheri, A. J. El-Sayed, M. A. Bryant, J. Bunz, U.},
	month = {Mar},
	pages = {4876-4876},
	isbn = {1932-7447},
	doi = {10.1021/jp4006197},
	author = {Mahmoud, M A and Poncheri, A. J. and El-Sayed, M. A. and Bryant, J. and Bunz, U.}
}
@article {1378,
	title = {Surface-Enhanced Raman Spectroscopy for Real-Time Monitoring of Reactive Oxygen Species-Induced DNA Damage and Its Prevention by Platinum Nanoparticles},
	journal = {Acs Nano},
	volume = {7},
	number = {9},
	year = {2013},
	note = {Panikkanvalappil, Sajanlal R. Mahmoud, Mahmoud A. Mackey, Megan A. El-Sayed, Mostafa A.},
	month = {Sep},
	pages = {7524-7533},
	isbn = {1936-0851},
	doi = {10.1021/nn403722x},
	author = {Panikkanvalappil, S. R. and Mahmoud, M A and Mackey, M. A. and El-Sayed, M. A.}
}
@proceedings {1377,
	title = {Toxicities and antitumor efficacy of tumor-targeted AuNRs in mouse model},
	volume = {73},
	number = {8},
	year = {2013},
	publisher = {AMER ASSOC CANCER RESEARCH 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA},
	isbn = {0008-5472},
	author = {Peng, Xianghong and Mackey, Megan and Austin, Lauren and Oyelere, Adegboyega and Chen, Georgia and Huang, Xiaohua and El-Sayed, Mostafa A. and Shin, Dong M}
}
@article {1393,
	title = {Well-organized raspberry-like Ag@ Cu bimetal nanoparticles for highly reliable and reproducible surface-enhanced Raman scattering},
	journal = {Nanoscale},
	volume = {5},
	number = {23},
	year = {2013},
	pages = {11620-11624},
	author = {Lee, Jung-Pil and Chen, Dongchang and Li, Xiaxi and Yoo, Seungmin and Bottomley, Lawrence A and El-Sayed, Mostafa A. and Park, Soojin and Liu, Meilin}
}
@article {1331,
	title = {Aggregation and Interaction of Cationic Nanoparticles on Bacterial Surfaces},
	journal = {Journal of the American Chemical Society},
	volume = {134},
	number = {16},
	year = {2012},
	note = {Times Cited: 1Hayden, Steven C. Zhao, Gengxiang Saha, Krishnendu Phillips, Ronnie L. Li, Xiaoning Miranda, Oscar R. Rotello, Vincent M. El-Sayed, Mostafa A. Schmidt-Krey, Ingeborg Bunz, Uwe H. F.},
	month = {Apr},
	pages = {6920-6923},
	abstract = {Cationic monolayer-protected gold nanoparticles (AuNPs) with sizes of 6 or 2 nm interact with the cell membranes of Escherichia coli (Gram-) and Bacillus subtilis (Gram+), resulting in the formation of strikingly distinct AuNP surface aggregation patterns or lysis depending upon the size of the AuNPs. The aggregation phenomena were investigated by transmission electron microscopy and UV-vis spectroscopy. Upon proteolytic treatment of the bacteria, the distinct aggregation patterns disappeared.},
	isbn = {0002-7863},
	doi = {10.1021/ja301167y},
	author = {Hayden, S. C. and Zhao, G. X. and Saha, K. and Phillips, R. L. and Li, X. N. and Miranda, O. R. and Rotello, V. M. and El-Sayed, M. A. and Schmidt-Krey, I. and Bunz, U. H. F.}
}
@article {1329,
	title = {Antiandrogen Gold Nanoparticles Dual-Target and Overcome Treatment Resistance in Hormone-Insensitive Prostate Cancer Cells},
	journal = {Bioconjugate Chemistry},
	volume = {23},
	number = {8},
	year = {2012},
	note = {Times Cited: 0Dreaden, Erik C. Gryder, Berkley E. Austin, Lauren A. Defo, Brice A. Tene Hayden, Steven C. Pi, Min Quarles, L. Darryl Oyelere, Adegboyega K. El-Sayed, Mostafa A.},
	month = {Aug},
	pages = {1507-1512},
	abstract = {prostate cancer is the most commonly diagnosed cancer among men in the developed countries.(1) One in six males in the U.S.(2) and one in nine males in the U.K.(3) will develop the disease at some point during their lifetime. Despite advances in prostate cancer screening, more than a quarter of a million men die from the disease every year(1) due primarily to treatment-resistance and metastasis. Colloidal nanotechnologies can provide tremendous enhancements to existing targeting/treatment strategies for prostate cancer to which malignant cells are less sensitive. Here, we show that antiandrogen gold nanoparticles-multivalent analogues of antiandrogens currently used in clinical therapy for prostate cancer-selectively engage two distinct receptors, androgen receptor (AR), a target for the treatment of prostate cancer, as well as a novel G-protein coupled receptor, GPRC6A, that is also upregulated in prostate cancer. These nanoparticles selectively accumulated in hormone-insensitive and chemotherapy resistant prostate cancer cells, bound androgen receptor with multivalent affinity, and exhibited greatly enhanced drug potency versus monovalent antiandrogens currently in clinical use Further, antiandrogen gold nanoparticles selectively stimulated GPRC6A with multivalent affinity, demonstrating that the delivery of nanoscale antiandrogens can also be facilitated by the transmembrane receptor in order to realize increasingly selective, increasingly potent therapy for treatment-resistant prostate cancers.},
	isbn = {1043-1802},
	doi = {10.1021/bc300158k},
	author = {Dreaden, E. C. and Gryder, B. E. and Austin, Lauren and Defo, B. A. T. and Hayden, S. C. and Pi, M. and Quarles, L. D. and Oyelere, A. K. and El-Sayed, M. A.}
}
@article {1417,
	title = {Nano and Molecular Science and Technology Special Issue Honoring Paul Barbara},
	journal = {Accounts of Chemical Research},
	volume = {45},
	number = {11},
	year = {2012},
	month = {2012/11/20},
	pages = {1842-1843},
	publisher = {American Chemical Society},
	isbn = {0001-4842},
	doi = {10.1021/ar300271q},
	author = {El-Sayed, Mostafa and Masuhara, Hiroshi and Pileni, Marie-Paule and Landes, Christy}
}
@article {1342,
	title = {Pronounced Effects of Anisotropy on Plasmonic Properties of Nanorings Fabricated by Electron Beam Lithography},
	journal = {Nano Letters},
	volume = {12},
	number = {4},
	year = {2012},
	note = {Times Cited: 3Near, Rachel Tabor, Christopher Duan, Jinsong Pachter, Ruth El-Sayed, Mostafa},
	month = {Apr},
	pages = {2158-2164},
	abstract = {Gold nanoring dimers were fabricated via EBL with dimensions of 127.6 +/- 2.5 and 57.8 +/- 2.3 nm for the outer and inner diameters, respectively, with interparticle separations ranging from 17.8 +/- 3.4 to 239.2 +/- 3.7 nm. The coupling between the inner and outer surfaces of a single nanoring renders it very sensitive to any anisotropy. We found that anisotropy in the particle geometry and anisotropy introduced by the substrate combine to create very unique spectral features in this system.},
	isbn = {1530-6984},
	doi = {10.1021/nl300622p},
	author = {Near, R. and Tabor, C. and Duan, J. S. and Pachter, R. and El-Sayed, M.}
}
@article {1338,
	title = {Properties of pi-Conjugated Fluorescence Polymer-Plasmonic Nanoparticles Hybrid Materials},
	journal = {Journal of Physical Chemistry C},
	volume = {116},
	number = {24},
	year = {2012},
	note = {Times Cited: 1Mahmoud, M. A. Poncheri, A. J. El-Sayed, M. A.},
	month = {Jun},
	pages = {13336-13342},
	abstract = {Recently, great interest has risen in studying and using hybrid material made by mixing polymeric materials with plasmonic nanoparticles. In the present work, the photophysical properties of two poly(p-phenyleneethynylene) fluorescent polymers, varying in chain length, were studied as a function of (1) pure polymer surface compression after deposition from a Langmuir-Blodgett trough onto a substrate and (2) deposition of a constant amount of polymer onto the surface of silver nanocube arrays of varying particle densities. The results are discussed in terms of the surface pressure and nanoparticle topography effects on conformation of the fluorescent polymer. It was found that the short polymer is much less affected by increased surface pressure, remaining isolated from interchain interaction. The long polymer exhibits signs of conjugation breaking, presumably due to compression of its longer, "tangled", structure. The two polymer chains in the nanoparticle/polymer series of experiments exhibited a blue-shift and a substantial narrowing of their emission spectra when deposited onto the lowest surface pressure nanoparticle sample. With increasing nanoparticle density, the spectra continue to blue-shift and narrow. This effect is presumably a combined effect of conformational changes that shift the emission to higher energy (blue-shift) and plasmonic effects that result in enhancement of primary emission of the polymer (emission from the 0-0 and 1-0 transitions), thus narrowing the emission.},
	isbn = {1932-7447},
	doi = {10.1021/jp303908e},
	author = {Mahmoud, M A and Poncheri, A. J. and El-Sayed, M. A.}
}
@article {1083,
	title = {Plasmonic Enhancement of Nonradiative Charge Carrier Relaxation and Proposed Effects from Enhanced Radiative Electronic Processes in Semiconductor-Gold Core-Shell Nanorod Arrays},
	journal = {Journal of Physical Chemistry C},
	volume = {115},
	number = {13},
	year = {2011},
	note = {Dreaden, Erik C. Neretina, Svetlana Qian, Wei El-Sayed, Mostafa A. Hughes, Robert A. Preston, John S. Mascher, Peter},
	month = {Apr},
	pages = {5578-5583},
	abstract = {Plasmonic field enhancement of nonradiative exciton relaxation rates in vertically aligned arrays of high aspect ratio CdTe-Au core-shell nanorods was investigated by transient absorption spectroscopy, computational electromagnetics, and kinetic modeling. Increasing shell thickness in the high aspect ratio nanorods was found to result in dramatic differences in polarization-dependent nonradiative exciton relaxation rates, which we attribute to differing mechanisms of plasmonic field enhancement associated with predominant ground- or excited-state absorption processes. These results are compared with previous investigations of low aspect ratio CdTe-Au core-shell nanorods, and overall conclusions regarding plasmonic enhancement of nonradiative relaxation rates in this system are presented. We propose that when the resonantly coupled dipolar plasmon field of the shell is polarized parallel to the ground-state absorption transition moment of the core, Auger recombination dominates carrier relaxation and slower second-order decay kinetics are observed. When contributions of the resonantly coupled plasmon field are nondipolar or orthogonal to the ground-state absorption transition moment of the core, excited-state absorption processes are believed to dominate and increasingly rapid first-order relaxation kinetics are observed. We find that these processes can vary greatly, depending on shell thickness and the orientation of the array, but are insensitive to aspect ratio. These investigations have significant implications in the design of photovoltaic and optoelectronic devices incorporating anisotropic plasmonic elements.},
	isbn = {1932-7447},
	doi = {10.1021/jp112129k},
	author = {Dreaden, Erik and Neretina, Svetlana and Qian, Wei and El-Sayed, Mostafa A and Hughes, Robert A and Preston, John S and Mascher, Peter}
}
@article {1087,
	title = {Vertically Oriented Ti-Pd Mixed Oxynitride Nanotube Arrays for Enhanced Photoelectrochemical Water Splitting},
	journal = {Acs Nano},
	volume = {5},
	number = {6},
	year = {2011},
	note = {Allam, Nageh K. Poncheri, Adam J. El-Sayed, Mostafa A.},
	month = {Jun},
	pages = {5056-5066},
	abstract = {In recent years, considerable efforts have been made to design and discover photoactive nanostructured materials that can be used as anodes in water photoelectrolysis cells. Herein, we report on the growth of a novel photoanode material composed of self-ordered, vertically oriented nanotube arrays of titanium palladium mixed oxynitride films via anodization of Ti-Pd alloy in an electrolyte solution of formamide containing NH(4)F at room temperature, followed by annealing in an ammonia atmosphere. The nanostructure topology was found to depend on both the anodization time and the applied voltage. Our results demonstrate the ability to grow mixed oxynitride nanotube array films that are several micrometers thick. The Ti-Pd oxynitride nanotube array films were utilized In solar-spectrum water photoelectrolysis, demonstrating a photocurrent density of 1.9 mA/cm(2) and a similar to 5-fold increase in the photoconversion efficiency under AM 1.5 illumination (100 mW/cm(2), 1.0 M KOH) compared to pure TiO(2) nanotubes fabricated and tested under the same conditions; The obtained efficiency is among the highest reported values for a TiO(2) nanotube-based photoelectrochemical cell. This enhancement in the photoconversion efficiency is related to the synergistic effects of Pd alloying, nitrogen doping, and the unique structural properties of the fabricated nanotube arrays.},
	isbn = {1936-0851},
	doi = {10.1021/nn201136t},
	author = {Allam, N. K. and Poncheri, A. J. and El-Sayed, Mostafa A}
}
@article {1104,
	title = {Delivery of molecules into cells using carbon nanoparticles activated by femtosecond laser pulses},
	journal = {Nature Nanotechnology},
	volume = {5},
	number = {8},
	year = {2010},
	note = {Chakravarty, Prerona Qian, Wei El-Sayed, Mostafa A. Prausnitz, Mark R.},
	month = {Aug},
	pages = {607-611},
	abstract = {A major barrier to drug and gene delivery is crossing the cell{\textquoteright}s plasma membrane. Physical forces applied to cells via electroporation(1), ultrasound(2) and laser irradiation(3-6) generate nanoscale holes in the plasma membrane for direct delivery of drugs into the cytoplasm. Inspired by previous work showing that laser excitation of carbon nanoparticles can drive the carbon-steam reaction to generate highly controlled shock waves(7-10), we show that carbon black nanoparticles activated by femtosecond laser pulses can facilitate the delivery of small molecules, proteins and DNA into two types of cells. Our initial results suggest that interaction between the laser energy and carbon black nanoparticles may generate photo-acoustic forces by chemical reaction to create transient holes in the membrane for intracellular delivery.},
	isbn = {1748-3387},
	doi = {10.1038/nnano.2010.126},
	author = {Chakravarty, P. and Qian, Wei and El-Sayed, Mostafa A and Prausnitz, M. R.}
}
@article {1093,
	title = {Plasmonic Field Enhancement of the Exciton-Exciton Annihilation Process in a Poly(p-phenyleneethynylene) Fluorescent Polymer by Ag Nanocubes},
	journal = {Journal of the American Chemical Society},
	volume = {132},
	number = {8},
	year = {2010},
	note = {Mahmoud, Mahmoud A. Poncheri, Adam J. Phillips, Ronnie L. El-Sayed, Mostafa A.},
	month = {Mar},
	pages = {2633-2641},
	abstract = {Using the Langmuir-Blodgett (LB) technique, a poly(paraphenyleneethynylene) (PPE) fluorescent conjugated polymer was assembled on either a quartz substrate (system I) or on the surface of silver nanocube (AgNC) monolayers (system II). The fluorescence intensity of the polymer was studied in system I as a function of the surface density of the polymer sample when deposited on quartz substrates and in system II on the surface coverage of the underlying AgNC monolayers. In system I, a continual increase in the fluorescence intensity is observed as the surface density of excited polymer is increased. In system II, the fluorescence intensity of the polymer first increased until a threshold surface coverage of AgNC was reached, after which it decreased rapidly with increasing surface coverage in the AgNC monolayer. The exciting light intensity dependence is studied before and after this threshold in system II. The results suggest that one-photon processes were responsible for the increased intensity before the threshold, and two-photon processes were responsible for the rapid decrease in the polymer fluorescence intensity after the threshold. These observations are explained by the increase of the surface plasmon enhancement of the exciting light intensity as the nanoparticle surface coverage is increased. In turn, this increases the polymer absorption rate, which results in a continuous increase in the exciton density and is evident by an increase in the fluorescence intensity. At the threshold, the increased exciton density leads to an increase in the rate of exciton-exciton collisions, which leads to exciton-exciton annihilations. When this phenomenon becomes faster than the rate of fluorescence emission, an intensity decrease is observed. By exploiting the surface plasmon enhancement of absorption processes, we have observed the first exciton-exciton annihilation using a low-intensity Hg-lamp continuous wave source.},
	isbn = {0002-7863},
	doi = {10.1021/ja907657j},
	author = {Mahmoud, M A and Poncheri, A. J. and Phillips, R. L. and El-Sayed, Mostafa A}
}
@article {808,
	title = {A Reexamination of Active and Passive Tumor Targeting by Using Rod-Shaped Gold Nanocrystals and Covalently Conjugated Peptide Ligands},
	journal = {ACS Nano},
	volume = {4},
	year = {2010},
	note = {doi: 10.1021/nn102055s},
	month = {2010},
	pages = {5887 - 5896},
	publisher = {American Chemical Society},
	abstract = {The targeted delivery of nanoparticles to solid tumors is one of the most important and challenging problems in cancer nanomedicine, but the detailed delivery mechanisms and design principles are still not well understood. Here we report quantitative tumor uptake studies for a class of elongated gold nanocrystals (called nanorods) that are covalently conjugated to tumor-targeting peptides. A major advantage in using gold as a ?tracer? is that the accumulated gold in tumors and other organs can be quantitatively determined by elemental mass spectrometry (gold is not a natural element found in animals). Thus, colloidal gold nanorods are stabilized with a layer of polyethylene glycols (PEGs) and are conjugated to three different ligands: (i) a single-chain variable fragment (ScFv) peptide that recognizes the epidermal growth factor receptor (EGFR); (ii) an amino terminal fragment (ATF) peptide that recognizes the urokinase plasminogen activator receptor (uPAR); and (iii) a cyclic RGD peptide that recognizes the av?3 integrin receptor. Quantitative pharmacokinetic and biodistribution data show that these targeting ligands only marginally improve the total gold accumulation in xenograft tumor models in comparison with nontargeted controls, but their use could greatly alter the intracellular and extracellular nanoparticle distributions. When the gold nanorods are administered via intravenous injection, we also find that active molecular targeting of the tumor microenvironments (e.g., fibroblasts, macrophages, and vasculatures) does not significantly influence the tumor nanoparticle uptake. These results suggest that for photothermal cancer therapy, the preferred route of gold nanorod administration is intratumoral injection instead of intravenous injection.The targeted delivery of nanoparticles to solid tumors is one of the most important and challenging problems in cancer nanomedicine, but the detailed delivery mechanisms and design principles are still not well understood. Here we report quantitative tumor uptake studies for a class of elongated gold nanocrystals (called nanorods) that are covalently conjugated to tumor-targeting peptides. A major advantage in using gold as a ?tracer? is that the accumulated gold in tumors and other organs can be quantitatively determined by elemental mass spectrometry (gold is not a natural element found in animals). Thus, colloidal gold nanorods are stabilized with a layer of polyethylene glycols (PEGs) and are conjugated to three different ligands: (i) a single-chain variable fragment (ScFv) peptide that recognizes the epidermal growth factor receptor (EGFR); (ii) an amino terminal fragment (ATF) peptide that recognizes the urokinase plasminogen activator receptor (uPAR); and (iii) a cyclic RGD peptide that recognizes the av?3 integrin receptor. Quantitative pharmacokinetic and biodistribution data show that these targeting ligands only marginally improve the total gold accumulation in xenograft tumor models in comparison with nontargeted controls, but their use could greatly alter the intracellular and extracellular nanoparticle distributions. When the gold nanorods are administered via intravenous injection, we also find that active molecular targeting of the tumor microenvironments (e.g., fibroblasts, macrophages, and vasculatures) does not significantly influence the tumor nanoparticle uptake. These results suggest that for photothermal cancer therapy, the preferred route of gold nanorod administration is intratumoral injection instead of intravenous injection.},
	isbn = {1936-0851},
	url = {http://dx.doi.org/10.1021/nn102055s},
	author = {Huang, Xiaohua and Peng, Xianghong and Wang, Yiqing and Wang, Yuxiang and Shin, Dong M and El-Sayed, Mostafa A and Nie, Shuming}
}
@article {1114,
	title = {The Dependence of the Plasmon Field Induced Nonradiative Electronic Relaxation Mechanisms on the Gold Shell Thickness in Vertically Aligned CdTe-Au Core-Shell Nanorods},
	journal = {Nano Letters},
	volume = {9},
	number = {11},
	year = {2009},
	note = {Neretina, Svetlana Dreaden, Erik C. Qian, Wei El-Sayed, Mostafa A. Hughes, Robert A. Preston, John S. Mascher, Peter},
	month = {Nov},
	pages = {3772-3779},
	abstract = {The dependence of the plasmon field enhancement of the nonradiative relaxation rate of the band gap electrons in vertically aligned CdTe-Au core-shell nanorods on the plasmonic gold nanoshell thickness is examined. Increasing the thickness of the gold nanoshell from 15 to 26 nm is found to change the decay curve from being nonexponential and anisotropic to one that is fully exponential and isotropic (i.e., independent of the nanorod orientation with respect to the exciting light polarization direction). Analysis of the kinetics of the possible electronic relaxation enhancement mechanisms is carried out, and DDA simulated properties of the induced plasmonic field of the thin and thick gold nanoshells are determined. On the basis of the conclusions of these treatments and the experimental results, it is concluded that by increasing the nanoshell thickness the relaxation processes evolve from multiple enhancement mechanisms, dominated by highly anisotropic Auger processes, to mechanism(s) involving first-order excited electron ejection process(es). The former is shown to give rise to nonexponential anisotropic decays in the dipolar plasmon field of the thin nanoshell, while the latter exhibits an exponential isotropic decay in the unpolarized plasmonic field of the thick nanoshell.},
	isbn = {1530-6984},
	doi = {10.1021/nl901960w},
	author = {Neretina, Svetlana and Dreaden, Erik and Qian, Wei and El-Sayed, Mostafa A and Hughes, Robert A and Preston, John S and Mascher, Peter}
}
@article {1113,
	title = {Exciton Lifetime Tuning by Changing the Plasmon Field Orientation with Respect to the Exciton Transition Moment Direction: CdTe-Au Core-Shell Nanorods},
	journal = {Nano Letters},
	volume = {9},
	number = {3},
	year = {2009},
	note = {Neretina, Svetlana Qian, Wei Dreaden, Erik C. El-Sayed, Mostafa A. Hughes, Robert A. Preston, John S. Mascher, Peter},
	month = {Mar},
	pages = {1242-1248},
	abstract = {We studied the anisotropy of the influence of plasmonic fields, arising from the optical excitation of a gold nanoshell plasmon absorption at 770 nm, on the lifetime of the bandgap state of the CdTe core in vertically aligned CdTe-Au core-shell nanorods. The previously observed decrease in the lifetime was studied as a function of the tilt angle between the long axis of the nanorod and the electric field polarization direction of the plasmon inducing exciting light. It is observed that the strongest enhancement to the exciton relaxation rate occurs when the two axes are parallel to one another. These results are discussed in terms of the coupling between the exciton transition moment of the CdTe rod and the electric field polarization direction of the gold nanoshell plasmon at 770 nm, which was determined from theoretical modeling based on the discrete dipole approximation.},
	isbn = {1530-6984},
	doi = {10.1021/nl900183m},
	author = {Neretina, Svetlana and Qian, Wei and Dreaden, Erik and El-Sayed, Mostafa A and Hughes, Robert A and Preston, John S and Mascher, Peter}
}
@article {1131,
	title = {Gold nanorod assisted near-infrared plasmonic photothermal therapy (PPTT) of squamous cell carcinoma in mice},
	journal = {Cancer Letters},
	volume = {269},
	number = {1},
	year = {2008},
	note = {Dickerson, Erin B. Dreaden, Erik C. Huang, Xiaohua El-Sayed, Ivan H. Chu, Hunghao Pushpanketh, Sujatha McDonald, John F. El-Sayed, Mostafa A.},
	month = {Sep},
	pages = {57-66},
	abstract = {Plasmonic photothermal therapy (PPTT) is a minimally-invasive oncological treatment strategy in which photon energy is selectively administered and converted into heat sufficient to induce cellular hyperthermia. The present work demonstrates the feasibility of in vivo PPTT treatment of deep-tissue malignancies using easily-prepared plasmonic gold nanorods and a small, portable, inexpensive near-infrared (NIR) laser. Dramatic size decreases in squamous cell carcinoma xenografts were observed for direct (P < 0.0001) and intravenous (P < 0.0008) administration of pegylated gold nanorods in nu/nu mice. Inhibition of average tumor growth for both delivery methods was observed over a 13-day period, with resorption of >57\% of the directly-injected tumors and 25\% of the intravenously-treated tumors. Published by Elsevier Ltd.},
	isbn = {0304-3835},
	doi = {10.1016/j.canlet.2008.04.026},
	author = {Dickerson, E. B. and Dreaden, Erik and Huang, Xiaohua and El Sayed, I.H. and Chu, H. H. and Pushpanketh, S. and McDonald, J. F. and El-Sayed, Mostafa A}
}
@article {811,
	title = {Plasmon Field Effects on the Nonradiative Relaxation of Hot Electrons in an Electronically Quantized System: CdTe-Au Core-Shell Nanowires},
	journal = {Nano Letters},
	volume = {8},
	year = {2008},
	note = {doi: 10.1021/nl801303g},
	month = {2008},
	pages = {2410 - 2418},
	publisher = {American Chemical Society},
	abstract = {The intense electromagnetic fields of plasmonic nanoparticles, resulting from the excitation of their localized surface plasmon oscillations, are known to enhance radiative processes. Their effect on the nonradiative electronic processes, however, is not as well-documented. Here, we report on the enhancement of the nonradiative electronic relaxation rates in CdTe nanowires upon the addition of a thin gold nanoshell, especially at excitation energies overlapping with those of the surface plasmon oscillations. Some possible mechanisms by which localized surface plasmon fields can enhance nonradiative relaxation processes of any quantized electronic excitations are proposed.The intense electromagnetic fields of plasmonic nanoparticles, resulting from the excitation of their localized surface plasmon oscillations, are known to enhance radiative processes. Their effect on the nonradiative electronic processes, however, is not as well-documented. Here, we report on the enhancement of the nonradiative electronic relaxation rates in CdTe nanowires upon the addition of a thin gold nanoshell, especially at excitation energies overlapping with those of the surface plasmon oscillations. Some possible mechanisms by which localized surface plasmon fields can enhance nonradiative relaxation processes of any quantized electronic excitations are proposed.},
	isbn = {1530-6984},
	doi = {10.1021/nl801303g},
	url = {http://dx.doi.org/10.1021/nl801303g},
	author = {Neretina, Svetlana and Qian, Wei and Dreaden, Erik and El-Sayed, Mostafa A and Hughes, Robert A and Preston, John S and Mascher, Peter}
}
@article {1159,
	title = {Size-dependent ultrafast electronic energy relaxation and enhanced fluorescence of copper nanoparticles},
	journal = {Journal of Physical Chemistry B},
	volume = {110},
	number = {1},
	year = {2006},
	note = {Darugar, Q Qian, W El-Sayed, MA Pileni, MP},
	month = {Jan},
	pages = {143-149},
	abstract = {The energy relaxation of the electrons in the conduction band of 12 and 30 nm diameter copper nanoparticles in colloidal solution was investigated using femtosecond time-resolved transient spectroscopy. Experimental results show that the hot electron energy relaxation is faster in 12 nm copper nanoparticles (0.37 ps) than that in 30 nm copper nanoparticles (0.51 ps), which is explained by the size-dependent electron-surface phonon coupling. Additional mechanisms involving trapping or energy transfer processes to the denser surface states (imperfection) in the smaller nanoparticles are needed to explain the relaxation rate in the 12 nm nanoparticles. The observed fluorescence quantum yield from these nanoparticles is found to be enhanced by roughly 5 orders of magnitude for the 30 nm nanoparticles and 4 orders of magnitude for the 12 nm nanoparticles (relative to bulk copper metal). The increase in the fluorescence quantum yield is attributed to the electromagnetic enhancement of the radiative recombination of the electrons in the s-p conduction band below the Fermi level with the holes in the d bands due to the strong surface plasmon oscillation in these nanoparticles.},
	isbn = {1520-6106},
	doi = {10.1021/jp0545445},
	author = {Darugar, Q. and Qian, Wei and El-Sayed, Mostafa A and Pileni, Marie-Paule}
}
@article {1183,
	title = {Model system for growing and quantifying Streptococcus pneumoniae biofilms in situ and in real time},
	journal = {Applied and Environmental Microbiology},
	volume = {70},
	number = {8},
	year = {2004},
	note = {Donlan, RM Piede, JA Heyes, CD Sanii, L Murga, R Edmonds, P El-Sayed, I El-Sayed, MA},
	month = {Aug},
	pages = {4980-4988},
	abstract = {Streptococcus pneumoniae forms biofilms, but little is known about its extracellular polymeric substances (EPS) or the kinetics of biofilm formation. A system was developed to enable the simultaneous measurement of cells and the EPS of biofilm-associated S. pneumoniae in situ over time. A biofilm reactor containing germanium coupons was interfaced to an attenuated total reflectance (ATR) germanium cell of a Fourier transform infrared (FTIR) laser spectrometer. Biofilm-associated cells were recovered from the coupons and quantified by total and viable cell count methods. ATR-FTIR spectroscopy of biofilms formed on the germanium internal reflection element (IRE) of the ATR cell provided a continuous spectrum of biofilm protein and polysaccharide (a measure of the EPS). Staining of the biofilms on the IRE surface with specific fluorescent probes provided confirmatory evidence for the biofilm structure and the presence of biofilm polysaccharides. Biofilm protein and polysaccharides were detected within hours after inoculation and continued to increase for the next 141 h. The polysaccharide band increased at a substantially higher rate than did the protein band, demonstrating increasing coverage of the IRE surface with biofilm polysaccharides. The biofilm total cell counts on germanium coupons stabilized after 21 h, at approximately 10(5) cells per cm(2), while viable counts decreased as the biofilm aged. This system is unique in its ability to detect and quantify biofilm-associated cells and EPS of S. pneumoniae over time by using multiple, corroborative techniques. This approach could prove useful for the study of biofilm processes of this or other microorganisms of clinical or industrial relevance.},
	isbn = {0099-2240},
	doi = {10.1128/aem.70.8.4980-4988.2004},
	author = {Donlan, R. M. and Piede, J. A. and Heyes, C D and Sanii, L. S. and Murga, R. and Edmonds, P. and El Sayed, I.H. and El-Sayed, Mostafa A}
}
@article {840,
	title = {Picosecond Self-Induced Thermal Lensing from Colloidal Silver Nanodisks},
	journal = {The Journal of Physical Chemistry B},
	volume = {108},
	year = {2004},
	note = {doi: 10.1021/jp049943z},
	month = {2004},
	pages = {5230 - 5234},
	publisher = {American Chemical Society},
	abstract = {The optical and nonradiative relaxation dynamics of 5 nm thick silver nanodisks with a 25 nm diameter have been investigated in an organic solvent by continuous wave (cw) and femtosecond pump?probe time-resolved spectroscopies. Several surface plasmon absorption bands are observed due to the disk shape of these particles. In the time-resolved experiments, the time dependence of the bleach resulting from femtosecond pulsed excitation is studied. On the 1?3 ps time scale, a decay resulting from electron?phonon relaxation is observed. On a longer time scale (>20 ps), a rise rather than a further decay of the bleach intensity is observed. This is shown to result from the formation of a thermal lens due to the induced thermal gradients produced from heating the organic solvent by the phonon?phonon relaxation processes of the photoexcited nanodisks.The optical and nonradiative relaxation dynamics of 5 nm thick silver nanodisks with a 25 nm diameter have been investigated in an organic solvent by continuous wave (cw) and femtosecond pump?probe time-resolved spectroscopies. Several surface plasmon absorption bands are observed due to the disk shape of these particles. In the time-resolved experiments, the time dependence of the bleach resulting from femtosecond pulsed excitation is studied. On the 1?3 ps time scale, a decay resulting from electron?phonon relaxation is observed. On a longer time scale (>20 ps), a rise rather than a further decay of the bleach intensity is observed. This is shown to result from the formation of a thermal lens due to the induced thermal gradients produced from heating the organic solvent by the phonon?phonon relaxation processes of the photoexcited nanodisks.},
	isbn = {1520-6106},
	doi = {10.1021/jp049943z},
	url = {http://dx.doi.org/10.1021/jp049943z},
	author = {Maillard, Mathieu and Pileni, Marie-Paule and Link, Stephan and El-Sayed, Mostafa A}
}
@article {1178,
	title = {Picosecond self-induced thermal lensing from colloidal silver nanodisks},
	journal = {Journal of Physical Chemistry B},
	volume = {108},
	number = {17},
	year = {2004},
	note = {Maillard, M Pileni, MP Link, S El-Sayed, MA},
	month = {Apr},
	pages = {5230-5234},
	abstract = {The optical and nonradiative relaxation dynamics of 5 unit thick silver nanodisks with a 25 nm diameter have been investigated in an organic solvent by continuous wave (cw) and femtosecond pump-probe time-resolved spectroscopies. Several surface plasmon absorption bands are observed due to the disk shape of these particles. In the time-resolved experiments, the time dependence of the bleach resulting from femtosecond pulsed excitation is studied. On the 1-3 ps time scale, a decay resulting from electron-phonon relaxation is observed. On a longer time scale (>20 ps), a rise father than a further decay of the bleach intensity is observed. This is shown to result from the formation of a thermal lens due to the induced thermal gradients produced from heating the organic solvent by the phonon-phonon relaxation processes of the photoexcited nanodisks.},
	isbn = {1520-6106},
	doi = {10.1021/jp049943z},
	author = {Maillard, Mathieu and Pileni, Marie-Paule and Link, Stephan and El-Sayed, Mostafa A}
}
@article {846,
	title = {FTIR study of the adsorption of the capping material to different platinum nanoparticle shapes},
	journal = {The Journal of Physical Chemistry A},
	volume = {107},
	year = {2003},
	pages = {8371-8375},
	publisher = {ACS Publications},
	abstract = {FTIR spectroscopy has been used to study the binding geometry of polyacrylate capping material on cubic and tetrahedral platinum nanoparticles. It is proposed that the capping material forms an ester-like linkage to the Pt surface on the tetrahedral shapes through the hydroxyl oxygen atom of the carboxylic acid moiety of the polyacrylate (linear adsorption configuration). On the cubic particle the adsorption is through both of the carboxylic oxygen atoms (bridge adsorption configuration). These shaped nanoparticles are synthesized by changing the starting ratio of the capping material to that of the Pt salt. The results are discussed in terms of the effect of changing the concentration of the polyacrylate capping material on the mode of bonding to the surface. This might be a factor in determining the final shape formed.},
	isbn = {1089-5639},
	doi = {10.1021/jp0300694},
	url = {http://dx.doi.org/10.1021/jp0300694},
	author = {Petroski, J. M. and El-Sayed, Mostafa A}
}
@article {1208,
	title = {Self-assembly of platinum nanoparticles of various size and shape},
	journal = {Journal of Physical Chemistry A},
	volume = {105},
	number = {23},
	year = {2001},
	note = {Petroski, JM Green, TC El-Sayed, MA},
	month = {Jun},
	pages = {5542-5547},
	abstract = {The addition of dodecanethiol to a polydisperse platinum colloidal aqueous solution capped with acrylic acid leads to self-assembled monolayers which not only contain various sizes, but also various shapes of nanoparticles. Assembled monolayers arranged in hcp arrays are achieved for mixed shape-samples. In;the case of the assembly of cubic nanoparticles, cubic closest packing is achieved when the size difference between the nanoparticles is less than 25\% (or between 6 and 8 nm). The ccp array is disrupted when the size difference is between 25 and 60\% or there is a mixture of shapes. Finally, size segregation is seen in regions where the size difference is more than 60\% with the resultant assembly being hcp no matter what the shape.},
	isbn = {1089-5639},
	doi = {10.1021/jp0019207},
	author = {Petroski, J. M. and Green, T.C. and El-Sayed, Mostafa A}
}
@article {1230,
	title = {Activation energy of the reaction between hexacyanoferrate(III) and thiosulfate ions catalyzed by platinum nanoparticles},
	journal = {Journal of Physical Chemistry B},
	volume = {104},
	number = {47},
	year = {2000},
	note = {Li, Y Petroski, J El-Sayed, MA},
	month = {Nov},
	pages = {10956-10959},
	abstract = {A temperature-dependent study was carried out for the platinum-nanoparticle-catalyzed electron-transfer reaction between hexacyanoferrate(III) and thiosulfate ions in the temperature range of 20-70 degreesC. The Pt nanoparticles are dominantly truncated octahedral in shape and have an average particle size of 7.0 +/- 0.8 nm. The catalyzed reaction is compared with the uncatalyzed reaction in the same temperature range. The activation energy of the reaction is found to be 38.3 +/- 2.0 kJ/mol for the uncatalyzed reaction and 17.6 +/- 0.9 kJ/mol for the catalyzed reaction in the lower temperature range (20-50 degreesC). In the higher temperature range (50-70 degreesC), the rate remains nearly constant. This behavior is attributed to the cancellation of two effects: the temperature dependence of the catalytic reaction and the decrease in the catalyst surface area due to the increase of nanoparticle aggregation.},
	isbn = {1089-5647},
	doi = {10.1021/jp002569s},
	author = {Li, Y. and Petroski, J. M. and El-Sayed, Mostafa A}
}
@article {1252,
	title = {Kinetically controlled growth and shape formation mechanism of platinum nanoparticles},
	journal = {Abstracts of Papers of the American Chemical Society},
	volume = {215},
	year = {1998},
	note = {Petroski, JM Wang, ZL Green, TC El-Sayed, MAPart 2},
	month = {Apr},
	pages = {U176-U176},
	isbn = {0065-7727},
	author = {Petroski, J. M. and Wang, Z.L. and Green, T.C. and El-Sayed, Mostafa A}
}
@article {1249,
	title = {Shape transformation and surface melting of cubic and tetrahedral platinum nanocrystals},
	journal = {Journal of Physical Chemistry B},
	volume = {102},
	number = {32},
	year = {1998},
	note = {Wang, ZL Petroski, JM Green, TC El-Sayed, MA},
	month = {Aug},
	pages = {6145-6151},
	abstract = {We report transmission electron microscopic studies of in-situ temperature-induced shape transformation and melting behavior of polymer-capped cubic and tetrahedral nanocrystals. Our results indicate that the surface-capping polymer is removed by annealing the specimen at temperatures between 180 and 250 degrees C. The particle shapes show no change up to similar to 350 degrees C. In the temperature range between 350 and 450 degrees C, a small truncation occurs in the particle shapes but no major shape transformation is observed. The particle shapes experience a dramatic transformation into spherical-like shapes when the temperature is raised above similar to 500 degrees C, where surface diffusion or surface premelting (softening) takes place. Above 600 degrees C, surface melting becomes obvious leading to coalescence of the surfaces of neighboring nanocrystals and a decrease in the volume occupied by the assembled nanocrystals. The surface melting forms a liquid layer a few atomic layers deep around the still solid core of the nanocrystal. This temperature is much lower than the melting point of bulk metallic platinum (1769 degrees C). The reduction in the melting temperature is discussed in terms of the surface tension of the solid-liquid interface (gamma(SL)). For an 8 nm diameter Pt nanocrystal, gamma(SL) is calculated to be 2.0 N m(-1) at 650 degrees C, which is smaller than that of the bulk solid-vapor metal surface tension (gamma(sv)). This reduction is proposed to be due to the compensation of the increase in gamma(sv) of the nanocrystal by the wetting effect at the solid-liquid interface.},
	isbn = {1089-5647},
	doi = {10.1021/jp981594j},
	author = {Wang, Z.L. and Petroski, J. M. and Green, T.C. and El-Sayed, Mostafa A}
}
@article {856,
	title = {Femtosecond time-resolved two-photon photoemission studies of electron dynamics in metals},
	journal = {Progress in surface science},
	volume = {56},
	year = {1997},
	pages = {239-310},
	publisher = {Elsevier},
	abstract = {Electron-hole excitation and relaxation in the bulk, at interfaces, and surfaces of solid state materials play a key role in a variety of physical and chemical phenomena that are important for surface photochemistry, particle-surface interactions, and device physics. Information on charge carrier relaxation in metals can be obtained through analysis of linewidths measured by photoemission and related techniques, which give an estimate of the upper limit for electron and hole relaxation; however, many factors can contribute to spectral broadening, thus it is difficult to extract specific information on electronic relaxation processes. With femtosecond lasers it is possible to probe directly in a time-resolved fashion the charge carrier dynamics in metals by a variety of linear and nonlinear optical techniques. Femtosecond time-resolved two-photon photoemission has attracted particularly strong interest because it incorporates many of the surface analytical capabilities of photoemission and inverse photoemission {\textemdash} the traditional probes for surface and bulk band structures of solid state materials {\textemdash} with time-resolution that is approaching the fundamental response of electrons to optical excitation. Advances in the direct measurements of electron-hole excitation, charge carrier relaxation, and dynamics of intrinsic and adsorbate induced surface states are reviewed. With femtosecond lasers it also is possible to probe a variety of coherent phenomena, and even to control the charge carrier dynamics in metals through the optical phase of the excitation light. Pioneering experiments in this new field also are discussed.},
	isbn = {0079-6816},
	doi = {10.1016/S0079-6816(98)00002-1},
	url = {http://dx.doi.org/10.1016/S0079-6816(98)00002-1},
	author = {Petek, H. and Ogawa, S.}
}
