@article {1632,
	title = {Defect engineering in 1D Ti{\textendash}W oxide nanotube arrays and their correlated photoelectrochemical performance},
	journal = {Physical Chemistry Chemical Physics},
	year = {2018},
	chapter = {10258},
	author = {A.A. Abdelhafiz and M.A. Ganzoury and Amer, A. W. and A.A. Faiad and A.M. Khalifa and S.Y. AlQaradawi and El-Sayed, M. A. and Alamgir, F. M. and Allam, N. K.}
}
@article {1636,
	title = {Dual-excitation nanocellulose-plasmonic membranes for molecular and cellular SERS detection},
	journal = {ACS applied materials \& interfaces},
	year = {2018},
	author = {S. Zhang and R. Xiong and Mahmoud, M A and E. Quigley and H. Chang and El-Sayed, M. A. and Tsukruk, V. V.}
}
@article {1625,
	title = {Design of Hybrid Electrochromic Materials with Large Electrical Modulation of Plasmonic Resonances},
	journal = {ACS Applied Materials \& Interfaces},
	year = {2016},
	author = {Ledin, P. A. and et al.}
}
@article {1618,
	title = {Dual-Responsive Reversible Plasmonic Behavior of Core{\textendash}Shell Nanostructures with pH-Sensitive and Electroactive Polymer Shells},
	journal = {Chemistry of Materials},
	year = {2016},
	author = {Jeon, JW and et al.}
}
@article {1388,
	title = {Determining the Mechanism of Solution Metallic Nanocatalysis with Solid and Hollow Nanoparticles: Homogeneous or Heterogeneous},
	journal = {Journal of Physical Chemistry C},
	volume = {117},
	number = {42},
	year = {2013},
	note = {Mahmoud, Mahmoud A. Garlyyev, Batyr El-Sayed, Mostafa A.},
	month = {Oct},
	pages = {21886-21893},
	isbn = {1932-7447},
	doi = {10.1021/jp4079234},
	author = {Mahmoud, M A and Garlyyev, B. and El-Sayed, M. A.}
}
@article {1391,
	title = {Different Plasmon Sensing Behavior of Silver and Gold Nanorods},
	journal = {Journal of Physical Chemistry Letters},
	volume = {4},
	number = {9},
	year = {2013},
	note = {Mahmoud, Mahmoud A. El-Sayed, Mostafa A.},
	month = {May},
	pages = {1541-1545},
	isbn = {1948-7185},
	doi = {10.1021/jz4005015},
	author = {Mahmoud, M A and El-Sayed, M. A.}
}
@article {1328,
	title = {Detecting and Destroying Cancer Cells in More than One Way with Noble Metals and Different Confinement Properties on the Nanoscale},
	journal = {Accounts of Chemical Research},
	volume = {45},
	number = {11},
	year = {2012},
	note = {Times Cited: 0Dreaden, Erik C. El-Sayed, Mostafa A.Si},
	month = {Dec},
	pages = {1854-1865},
	abstract = {Today, 1 in 2 males and 1 in 3 females in the United States will develop cancer at some point during their lifetimes, and 1 in 4 males and 1 in 5 females in the United States will die from the disease. New methods for detection and treatment have dramatically improved dancer care in the United States. However, as improved detection and increasing exposure to carcinogens has led to higher rates of cancer incidence, dinidans and researchers have not balanced that increase with a similar decrease in cancer mortality rates. This mismatch highlights a dear and urgent need for increasingly potent and selective methods with which to detect and treat cancers at their earliest stages. Nanotechnology, the use of materials with structural features ranging from 1 to 100 nm in size, has dramatically altered the design, use, and delivery of cancer diagnostic and therapeutic agents. The unique and newly discovered properties of these structures can enhance the specificities with which biomedical agents are delivered, complementing their efficacy or diminishing unintended side effects. Gold (and silver) nanotechnologies afford a particularly unique set of physiological and optical properties which can be leveraged In applications ranging from in vitro/vivo therapeutics and drug delivery to imaging and diagnostics, surgical guidance, and treatment monitoring. Nanoscale diagnostic and therapeutic agents have been in use since the development of micellar nanocarriers and polymer drug nanoconjugates in the mid-1950s, liposomes by Bangham and Watkins in the mid-1960s, and the introduction of polymeric nanoparticles by Langer and Folkman in 1976. Since then, nanoscale constructs such as dendrimers, protein nanoconjugates, and inorganic nanoparticles have been developed for the systemic delivery of agents to specific disease sites. Today, more than 20 FDA-approved diagnostic or therapeutic nanotechnologies are in clinical use with roughly 250 others in clinical development The global market for nano-enabled medical technologies is expected to grow to $70-160 billion by 2015, rivaling the current market share of biologics worldwide. In this Account, we explore the emerging applications of noble metal nanotechnologies in cancer diagnostics and therapeutics carried out by our group and by others. Many of the novel biomedical properties associated with gold and silver nanoparticles arise from confinement effects: (i) the confinement of photons within the particle which can lead to dramatic electromagnetic scattering and absorption (useful in sensing and heating applications, respectively); (ii) the confinement of molecules around the nanoparticle (useful in drug delivery); and (iii) the cellular/subcellular confinement of particles within malignant cells (such as selective, nuclear-targeted cytotoxic DNA damage by gold nanoparticles). We then describe how these confinement effects relate to specific aspects of diagnosis and treatment such as (i) laser photothermal therapy, optical scattering microscopy, and spectroscopic detection, (ii) drug targeting and delivery, and (iii) the ability of these structures to act as intrinsic therapeutic agents which can selectively perturb/inhibit cellular functions such as division. We intend to provide the reader with a unique physical and chemical perspective on both the design and application of these technologies in cancer diagnostics and therapeutics. We also suggest a framework for approaching future research in the field.},
	isbn = {0001-4842},
	doi = {10.1021/ar2003122},
	author = {Dreaden, E. C. and El-Sayed, M. A.}
}
@article {1339,
	title = {Different Methods of Increasing the Mechanical Strength of Gold Nanocages},
	journal = {Journal of Physical Chemistry Letters},
	volume = {3},
	number = {23},
	year = {2012},
	note = {Times Cited: 0Mahmoud, Mahmoud A. Szymanski, Paul El-Sayed, Mostafa A.},
	month = {Dec},
	pages = {3527-3531},
	abstract = {Using the ultrafast coherent modulation of the surface plasmon band intensity with the totally symmetric lattice vibration of gold nanocages, we were able to determine and use their frequencies as a measure of the cage{\textquoteright}s mechanical stability. The presence of an inner "stiff" transition-metal nanoshell with a higher value of the elastic modulus is found to increase the frequency of the lattice vibration of the outer soft gold nanoshell. This could also explain the observed increase in both the gold lattice vibrational frequency as well as the lattice vibration relaxation time in the Au-Pt and Au-Pd double-shell nanocages. It is also found that when these nanoparticles are assembled into monolayers on quartz substrates by the Langmuir-Blodgett technique, the oscillation frequency of the gold shell with the transition metal having the largest elastic constant suffers the least change in its oscillation frequency as a result of its resistance to distortion as a result of binding to the substrate.},
	isbn = {1948-7185},
	doi = {10.1021/jz301503z},
	author = {Mahmoud, M A and Szymanski, P. and El-Sayed, M. A.}
}
@article {810,
	title = {Dark-field light scattering imaging of living cancer cell component from birth through division using bioconjugated gold nanoprobes},
	journal = {Journal of Biomedical Optics},
	volume = {15},
	year = {2010},
	pages = {046025},
	abstract = {Novel methods and technologies that could extend and complement the capabilities of the prevailing fluorescence microscope in following the cell cycle under different perturbations are highly desirable in the area of biological and biomedical imaging. We report a newly designed instrument for long-term light scattering live cell imaging based on integrating a homebuilt environmental cell incubation minichamber and an angled dark-field illumination system into a conventional inverted light microscope. Peptide-conjugated gold nanoparticles that are selectively delivered to either the cytoplasmic or nuclear region of the cell are used as light scattering contrast agents. The new system enables us to carry out continuous and intermittence-free dark-field live cell imaging over several tens of hours. A variety of applications of this imaging system are demonstrated, such as monitoring the nuclear uptake of peptide-conjugated gold nanoparticles, tracking the full cycle of cancer cells from birth to division, following the chromosome dynamics during cell mitosis, and observing the intracellular distribution of gold nanoparticles after cell division. We also discuss the overall effect of nuclear targeting gold nanoparticles on the cell viability of parent and daughter cells.},
	doi = {10.1117/1.3477179},
	url = {http://dx.doi.org/10.1117/1.3477179},
	author = {Qian, Wei and Huang, Xiaohua and Kang, Bin 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 {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 {1134,
	title = {Dependence of the threshold energy of femtosecond laser ejection of gold nanoprisms from quartz substrates on the nanoparticle environment},
	journal = {Journal of Physical Chemistry C},
	volume = {111},
	number = {25},
	year = {2007},
	note = {Tabor, Christopher Qian, Wei El-Sayed, Mostafa A.},
	month = {Jun},
	pages = {8934-8941},
	abstract = {Recently, it was reported that gold nanoprisms in a monolayer array on a quartz substrate were ejected in air when irradiated with femtosecond laser pulses near their surface plasmon absorption maximum. It was deduced from the measured reduction in particle thickness upon irradiation that the ejection mechanism involved ablation of surface atoms from the gold particle, which generates an intense pressure at the particle-substrate interface. The present study reports on this phenomenon when the substrate-bound nanoparticle is immersed in a liquid environment. In this system, it is found that the nanoparticle ejection requires less than one tenth the energy required if the system was irradiated in air. The ejected nanoparticle is also found to increase in thickness instead of the decrease observed in air. These results suggest another photoinitiated ejection mechanism, different from surface ablation, when the particles are surrounded by a liquid environment. From this and other spectroscopic and microscopic results on the ejected nanoprisms, we suggest a mechanism that involves energy transfer from the photoexcited nanoprism to the solvent within cavities and defects at the particle-substrate interface. The hot-solvent molecules result in an intense pressure at the particle-substrate interface, resulting in particle ejection. Ejection is proposed to consist of two processes, namely nanoparticle-substrate dissociation and nanoparticle solvation and diffusion away from the substrate. These two processes have independently been studied as a function of solvent property.},
	isbn = {1932-7447},
	doi = {10.1021/jp070282q},
	author = {Tabor, C. E. and Qian, Wei and El-Sayed, Mostafa A}
}
@article {1156,
	title = {Determination of the aspect ratio statistical distribution of gold nanorods in solution from a theoretical fit of the observed inhomogeneously broadened longitudinal plasmon resonance absorption spectrum},
	journal = {Journal of Applied Physics},
	volume = {100},
	number = {4},
	year = {2006},
	note = {Eustis, Susie El-Sayed, Mostafa A.},
	month = {Aug},
	abstract = {The determination of the statistical distribution of aspect ratios of a nanorod solution is desirable for experimentally synthesized solutions. The traditional method of using transmission electron microscopy (TEM) images for size determination gives statistically incorrect values due to distortions introduced by TEM sample preparation and by difficulties in counting a sufficiently large number of rods. In the present work, we propose a method to obtain the aspect ratio distribution using the observed longitudinal surface plasmon resonance absorption spectrum of gold nanorods in solution. The observed inhomogeneously broadened spectrum is fitted with a collection of homogeneously broadened spectra of nanorods each with a specific aspect ratio and population contribution using Gans extension [Ann. Phys. 47, 270 (1915)] of Mie theory. The fit generates an aspect ratio distribution for the rods in solution from which the median value and the statistical distribution are determined. This method is statistically more accurate, more convenient, and less expensive than the traditional method of TEM analysis on a solid substrate. (c) 2006 American Institute of Physics.},
	isbn = {0021-8979},
	doi = {10.1063/1.2244520},
	author = {Eustis, Susie and El-Sayed, Mostafa A}
}
@article {1152,
	title = {Determination of the minimum temperature required for selective photothermal destruction of cancer cells with the use of immunotargeted gold nanoparticles},
	journal = {Photochemistry and Photobiology},
	volume = {82},
	number = {2},
	year = {2006},
	note = {Huang, XH Jain, PK El-Sayed, IH El-Sayed, MA},
	month = {Mar-Apr},
	pages = {412-417},
	abstract = {Laser photothermal therapy of cancer with the use of gold nanoparticles immunotargeted to molecular markers on the cell surface has been shown to be an effective modality to selectively kill cancer cells at much lower laser powers than those needed for healthy cells. To elucidate the minimum light dosimetry required to induce cell death, photothermal destruction of two cancerous cell lines and a noncancerous cell line treated with antiepidermal growth factor receptor (anti-EGFR) anti body-conjugated gold nanoparticles is studied, and a numerical heat transport model is used to estimate the local temperature rise within the cells as a result of the laser heating of the gold nanoparticles. It is found that cell samples with higher nanoparticle loading require a lower incident laser power to achieve a certain temperature rise. Numerically estimated temperatures of 70-80 degrees C achieved by heating the gold particles agree well with the measured threshold temperature for destruction of the cell lines by oven heating and those measured in an earlier nanoshell method. Specific binding of anti-EGFR antibody to cancerous cells overexpressing EGFR selectively increases the gold nanoparticle loading within cancerous cells, thus allowing the cancerous cells to be destroyed at lower laser power thresholds than needed for the noncancerous cells. In addition, photothermal therapy using gold nanoparticles requires lower laser power thresholds than therapies using conventional dyes due to the much higher absorption coefficient of the gold nanoparticles.},
	isbn = {0031-8655},
	doi = {10.1562/2005-12-14-ra-754},
	author = {Huang, Xiaohua and Jain, Prashant K and El Sayed, I.H. and El-Sayed, Mostafa A}
}
@article {1168,
	title = {Dependence of the enhanced optical scattering efficiency relative to that of absorption for gold metal nanorods on aspect ratio, size, end-cap shape, and medium refractive index},
	journal = {Journal of Physical Chemistry B},
	volume = {109},
	number = {43},
	year = {2005},
	note = {Lee, KS El-Sayed, MA},
	month = {Nov},
	pages = {20331-20338},
	abstract = {The Current intense interest in the properties of plasmonic nanostructures for their applications in chemical and biochemical sensors, medical diagnostics and therapeutics, and biological imaging is fundamentally based on their enhanced optical absorption and scattering properties. In this study, the optical extinction, absorption, and scattering efficiencies were calculated as a function of shape definition, aspect ratio, surrounding medium, and material selection. The discrete dipole approximation method was used, which is known to be a very useful and versatile cornputational too] for particles with any arbitrary shape. Relative contribution of scattering to the total extinction for the longitudinal mode was found to be significantly dependent on the aspect ratio of the nanorod in a somewhat complex manner, different from a typical linear relationship for the resonance wavelength. A slight elongation of An nanosphere gives rise to a drastic increase in the relative scattering efficiency, which eventually reaches a maximum and begins to decrease with further increase in the aspect ratio. This is ascribed to the increasing absorptive contribution from the larger imaginary dielectric function of the metal particle in the longer wavelength region where the red-shifted excitation of the longitudinal resonance mode Occurs. For transverse mode exhibiting the blue-shift in the resonance peak, on the contrary, the absorption efficiency is relatively enhanced compared to the scattering efficiency with increasing aspect ratio. This is thought to result from the dominant effect of the interband transition present in this wavelength re-ion. Besides the dependence of plasmonic characteristics on the aspect ratio of nanorod, the DDA results for a small change of the end-cap shape and the index of the surrounding medium lead us to conclude that there exist two competing key factors: a weighting factor assigned to the shape parameter and the dielectric function of the metal particle, which control the relative enhancement in the scattering and absorption as well as the linearity of resonance wavelength with regard to the aspect ratio.},
	isbn = {1520-6106},
	doi = {10.1021/jp054385p},
	author = {Lee, K. S. and El-Sayed, Mostafa A}
}
@article {849,
	title = {Determination of the localization times of electrons and holes in the HgS well in a CdS/HgS/CdS quantum dot{\textendash}quantum well nanoparticle},
	journal = {Physical Review BPhys. Rev. B},
	volume = {66},
	year = {2002},
	month = {2002/11/11/},
	pages = {205312 - },
	publisher = {American Physical Society},
	abstract = {The femtosecond time-resolved electron-hole dynamics of the CdS/HgS/CdS quantum dot{\textendash}quantum well system (QDQW) was investigated as a function of excitation energy. In the transient absorption spectra four bleach bands and a stimulated emission signal in the visible spectral range between 450 and 780 nm were resolved. By using an IR probe pulse at 4.7 μm a transient induced absorption due to intraband transitions was found. The decay and rise times of these signals were measured when the CdS core or the HgS well of the nanoparticles was excited by the pump pulse. After excitation within the HgS well the transient signals rise within the resolution of our pump pulse, while after core excitation slower rise times were measured. From the 1.5 ps rise time of the stimulated emission originating from the HgS well and the intraband hole IR absorption (150 fs) after excitation into the CdS core, the electron localization time (transfer time from the core to the well) is found to be 1.5 ps while that of the hole is \~{}150 fs. This large difference in the observed dynamics of the electron and hole in crossing the CdS/HgS interface is discussed.},
	doi = {10.1103/PhysRevB.66.205312 },
	url = {http://link.aps.org/doi/10.1103/PhysRevB.66.205312},
	author = {Braun, Markus and Link, Stephan and Burda, Clemens and El-Sayed, Mostafa A}
}
@article {1204,
	title = {Direct observation of charge-transfer dynamics in a conjugated conducting polymer poly (3-octylthiophene)-fullerene composite by time-resolved infrared spectroscopy},
	journal = {Physical Review B},
	volume = {64},
	number = {23},
	year = {2001},
	note = {Wang, JP Li, Y Hong, XY El-Sayed, MA},
	month = {Dec},
	abstract = {Transient infrared-active vibrational (IRAV) modes observed in the pi -conjugated conducting polymers upon photoexcitation are usually used to characterize the dynamics of the photoinduced charge separation and recombination processes. In this paper, the dynamic behavior of photogenerated charge carrier in the poly(3-octylthiophene) (P3OT) conducting polymer doped with fullerene (C(60)) has been studied by using step-scan time-resolved Fourier-transform infrared spectroscopy at room temperature in the 2500-900-cm(-1) (0.31-0.11-eV) frequency region. Upon photoexcitation with a 10-ns laser pulses, it is observed that IRAV modes appear in the similar vibrational frequency regions for pure P3OT and C(60)-doped P3OT; however, the observed IRAV modes is enhanced by 800\% in intensity in the presence of small amount of C(60) (e.g., 10\%). Our results also show that the charge separation occurs instantaneously within the laser pulse width (10 ns), whereas the charge recombination processes occur in the microseconds to a few milliseconds time domain. In addition, the observed enhancement in the IRAV modes upon C(60) doping indicates an enhanced photogeneration efficiency of the charge separation.},
	isbn = {1098-0121},
	doi = {10.1103/PhysRevB.64.235413},
	author = {Wang, Jianping and Li, Y. and Hong, X. Y. and El-Sayed, Mostafa A}
}
@article {866,
	title = {Detection of a Yb3+ binding site in regenerated bacteriorhodopsin that is coordinated with the protein and phospholipid head groups.},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {93},
	year = {1996},
	month = {1996 Dec 10},
	pages = {14333-7},
	abstract = {Near infrared Yb3+ vibronic sideband spectroscopy was used to characterize specific lanthanide binding sites in bacteriorhodopsin (bR) and retinal free bacteriorhodopsin (bO). The VSB spectra for deionized bO regenerated with a ratio of 1:1 and 2:1 ion to bO are identical. Application of a two-dimensional anti-correlation technique suggests that only a single Yb3+ site is observed. The Yb3+ binding site in bO is observed to consist of PO2- groups and carboxylic acid groups, both of which are bound in a bidentate manner. An additional contribution most likely arising from a phenolic group is also observed. This implies that the ligands for the observed single binding site are the lipid head groups and amino acid residues. The vibronic sidebands of Yb3+ in deionized bR regenerated at a ratio of 2:1 ion to bR are essentially identical to those in bO. The other high-affinity binding site is thus either not evident or its fluorescence is quenched. A discussion is given on the difference in binding of Ca2+ (or Mg2+) and lanthanides in phospholipid membrane proteins.},
	keywords = {Bacteriorhodopsins, Binding Sites, Metals, Rare Earth, Phospholipids, Retinaldehyde, Spectroscopy, Near-Infrared},
	issn = {0027-8424},
	author = {Roselli, Cecile and Boussac, A and Mattioli, T A and Griffiths, Jennifer A. and El-Sayed, Mostafa A}
}
@article {1281,
	title = {Dynamics of Formation and Evaporation of Mixed Alkali Halide Nanocrystals: A Case of Comparable Lattice Energies},
	journal = {The Journal of Physical Chemistry},
	volume = {98},
	year = {1994},
	note = {doi: 10.1021/j100095a013},
	month = {1994},
	pages = {11316 - 11320},
	publisher = {American Chemical Society},
	abstract = {View http://dx.doi.org/10.1021/j100095a013 for article{\textquoteright}s front page in lieu of an abstract},
	isbn = {0022-3654},
	doi = {doi: 10.1021/j100095a013},
	url = {http://dx.doi.org/10.1021/j100095a013},
	author = {Ahmadi, Temer S. and El-Sayed, Mostafa A}
}
