@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 {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 {1638,
	title = {Real-Time Tracking of Autophagy Process in Living Cells Using Plasmonically Enhanced Raman Spectroscopy of Fucoidan-Coated Gold Nanoparticles},
	journal = {Journal of Materials Chemistry B},
	year = {2018},
	author = {Jang, H and K. Kang and El-Sayed, M. A.}
}
@article {1592,
	title = { Photoexcited Surface Frustrated Lewis Pairs for Heterogeneous Photocatalytic Co2 Reduction},
	journal = { Am. Chem. Soc. },
	year = {2016},
	author = {Ghuman, K. K. and Hoch, L. B. and Szymanski, P. and Loh, J. Y. and Kherani, N. P. and El-Sayed, M. A. and Ozin, G. A. and Singh, C. V.}
}
@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 {1580,
	title = {Probing molecular cell event dynamics at the single-cell level with targeted plasmonic gold nanoparticles: A review},
	journal = {Nano Today},
	year = {2015},
	pages = {-},
	keywords = {Rayleigh scattering},
	issn = {1748-0132},
	doi = {http://dx.doi.org/10.1016/j.nantod.2015.07.005},
	url = {http://www.sciencedirect.com/science/article/pii/S1748013215000973},
	author = {Lauren A. Austin and Bing Kang and El-Sayed, Mostafa A.}
}
@article {1576,
	title = {Silver nanocube aggregation gradient materials in search for total internal reflection with high phase sensitivity},
	journal = {Nanoscale},
	volume = {7},
	year = {2015},
	pages = {5230-5239},
	abstract = {We fabricated monolayer coatings of a silver nanocube aggregation to create a step-wise optical strip by applying different surface pressures during slow Langmuir-Blodgett deposition. The varying amount of randomly distributed nanocube aggregates with different surface coverages in gradient manner due to changes in surface pressure allows for continuous control of the polarization sensitive absorption of the incoming light over a broad optical spectrum. Optical characterization under total internal reflection conditions combined with electromagnetic simulations reveal that the broadband light absorption depends on the relative orientation of the nanoparticles to the polarization of the incoming light. By using computer simulations, we found that the electric field vector of the s-polarized light interacts with the different types of silver nanocube aggregations to excite different plasmonic resonances. The s-polarization shows dramatic changes of the plasmonic resonances at different angles of incidence (shift of 64 nm per 10[degree] angle of incidence). With a low surface nanocube coverage (from 5\% to 20\%), we observed a polarization-selective high absorption of 80\% (with an average 75\%) of the incoming light over a broad optical range in the visible region from 400 nm to 700 nm. This large-area gradient material with location-dependent optical properties can be of particular interest for broadband light absorption, phase-sensitive sensors, and imaging.},
	doi = {10.1039/C4NR06430E},
	url = {http://dx.doi.org/10.1039/C4NR06430E},
	author = {Konig, Tobias A. F. and Ledin, Petr A and Russell, Michael and Geldmeier, Jeffrey A and Mahmoud, Mahmoud. A. and El-Sayed, Mostafa A. and Tsukruk, Vladimir V.}
}
@article {1363,
	title = {Electrically Tunable Plasmonic Behavior of Nanocube-Polymer Nanomaterials Induced by a Redox Active Electrochromic Polymer},
	journal = {ACS nano},
	year = {2014},
	isbn = {1936-0851},
	author = {K{\"o}nig, Tobias AF and Ledin, Petr A and Kerszulis, Justin and Mahmoud, Mahmoud A. and El-Sayed, Mostafa A. and Reynolds, John R and Tsukruk, Vladimir V.}
}
@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 {1365,
	title = {Observing Real-Time Molecular Event Dynamics of Apoptosis in Living Cancer Cells using Nuclear-Targeted Plasmonically Enhanced Raman Nanoprobes},
	journal = {ACS nano},
	volume = {8},
	number = {5},
	year = {2014},
	pages = {4883-4892},
	isbn = {1936-0851},
	author = {Kang, Bin and Austin, Lauren and El-Sayed, Mostafa A.}
}
@article {1368,
	title = {P-Glycoprotein-Dependent Trafficking of Nanoparticle-Drug Conjugates},
	journal = {Small},
	volume = {10},
	number = {9},
	year = {2014},
	pages = {1719-1723},
	isbn = {1613-6829},
	author = {Dreaden, Erik C. and Raji, Idris O and Austin, Lauren and Fathi, Shaghayegh and Mwakwari, Sandra C and Humphries, William H and Kang, Bin and Oyelere, Adegboyega K and El-Sayed, Mostafa A}
}
@article {1364,
	title = {Silver Nanocube Aggregates in Cylindrical Pores for Higher Refractive Index Plasmonic Sensing},
	journal = {Particle \& Particle Systems Characterization},
	volume = {31},
	number = {2},
	year = {2014},
	pages = {274-283},
	isbn = {1521-4117},
	author = {K{\"o}nig, Tobias and Kodiyath, Rajesh and Combs, Zachary A. and Mahmoud, Mahmoud and El-Sayed, Mostafa A and Tsukruk, Vladimir V.}
}
@article {1357,
	title = {Stacked Gold Nanorectangles with Higher Order Plasmonic Modes and Top-Down Plasmonic Coupling},
	journal = {The Journal of Physical Chemistry C},
	volume = {118},
	number = {10},
	year = {2014},
	pages = {5453-5462},
	isbn = {1932-7447},
	author = {Malak, Sidney T. and König, Tobias and Near, Rachel and Combs, Zachary A. and El-Sayed, Mostafa A. and Tsukruk, Vladimir V.}
}
@article {1399,
	title = {Aptamer-Assisted Assembly of Gold Nanoframe Dimers},
	journal = {Particle \& Particle Systems Characterization},
	volume = {30},
	number = {12},
	year = {2013},
	pages = {1071-1078},
	isbn = {1521-4117},
	author = {Combs, Zachary A. and Malak, Sidney T. and K{\"o}nig, Tobias and Mahmoud, Mahmoud A. and Ch{\'a}vez, Jorge L and El-Sayed, Mostafa A and Kelley-Loughnane, Nancy and Tsukruk, Vladimir V.}
}
@article {1349,
	title = {Assemblies of silver nanocubes for highly sensitive SERS chemical vapor detection},
	journal = {J. Mater. Chem. A},
	volume = {1},
	number = {8},
	year = {2013},
	note = {CAPLUS AN 2013:172950(Journal; Online Computer File)},
	month = {//},
	pages = {2777-2788},
	publisher = {Royal Society of Chemistry},
	type = {10.1039/c2ta00867j},
	abstract = {Probably Ag nanocube (AgNC) aggregates within cylindrical pores (PAM-AgNC) can be employed as efficient nanostructures for highly efficient, robust, tunable, and reusable surface-enhanced Raman scattering (SERS) substrates for trace level org. vapor detection which is a challenging task in chem. detection. The authors demonstrate the ability to tune both the detection limit and the onset of signal satn. of the substrate by switching the adsorption behavior of AgNCs between highly aggregated and more disperse by varying the no. of adsorption-mediating polyelectrolyte bilayers on the pore walls of the membrane. The different AgNC distributions show large differences in the trace vapor detection limit of the common Raman marker benzenethiol (BT) and a widely used explosive binder N-Me-4-nitroaniline (MNA), demonstrating the importance of the large electromagnetic field enhancement assocd. with AgNC coupling. The SERS substrate with highly aggregated AgNCs within the cylindrical pores allows for consistent trace detection of mid ppb (\~{}500) for BT analyte, and a record limit of detection of low ppb (\~{}3) for MNA vapors with an estd. achievable limit of detection of \~{}600 ppt. The dispersed AgNC aggregates do not sat. at higher ppb concns., providing an avenue to distinguish between higher ppb concns. and increase the effective range of the SERS substrate design. A comparison between the AgNC substrate and an electroless deposition substrate with Ag quasi-nanospheres (PAM-AgNS) also demonstrates a higher SERS activity, and better detection limit, by the nanocube aggregates. This is supported by FDTD electromagnetic simulations that suggest that the higher integrated electromagnetic field intensity of the hot spots and the large specific interfacial areas impart greatly improved SERS for the AgNCs. Also, the AgNC substrate can be reused multiple times without significant loss of SERS activity which opens up new avenues for in-field monitoring. [on SciFinder(R)]},
	keywords = {polymer electrolyte film silver nanocube nanosphere SERS sensor explosive, porous alumina silver nanoparticle SERS substrate explosive, silver nanocube nanosphere SERS sensor benzenethiol methyl nitroaniline polyelectrolyte, vapor sensor silver nanoparticle SERS substrate},
	isbn = {2050-7496},
	doi = {10.1039/c2ta00867j},
	author = {Kodiyath, Rajesh and Malak, Sidney T. and Combs, Zachary A. and Koenig, Tobias and Mahmoud, Mahmoud A. and El-Sayed, Mostafa A. and Tsukruk, Vladimir V.}
}
@article {1395,
	title = {Exploiting the Nanoparticle Plasmon Effect: Observing Drug Delivery Dynamics in Single Cells via Raman/Fluorescence Imaging Spectroscopy},
	journal = {Acs Nano},
	volume = {7},
	number = {8},
	year = {2013},
	note = {Kang, Bin Afifi, Marwa M. Austin, Lauren A. El-Sayed, Mostafa A.},
	month = {Aug},
	pages = {7420-7427},
	isbn = {1936-0851},
	doi = {10.1021/nn403351z},
	author = {Kang, B. and Afifi, M. M. and Austin, Lauren and El-Sayed, M. A.}
}
@article {1347,
	title = {A New Nanotechnology Technique for Determining Drug Efficacy Using Targeted Plasmonically Enhanced Single Cell Imaging Spectroscopy},
	journal = {J Am Chem Soc},
	year = {2013},
	note = {MEDLINE AN 2013441929(Journal; Article; (JOURNAL ARTICLE))},
	month = {//},
	abstract = {Recently, we described a new technique, targeted plasmonically enhanced single cell imaging spectroscopy (T-PESCIS), which exploits the plasmonic properties of gold nanoparticles, e.g. gold nanospheres, to simultaneously obtain enhanced intracellular Raman molecular spectra and enhanced Rayleigh cell scattering images throughout the entire span of a single cell cycle. In the present work, we demonstrate the use of T-PESCIS in evaluating the relative efficacy and dynamics of two popular chemotherapy drugs on human oral squamous carcinoma (HSC-3) cells. T-PESCIS revealed three plasmonically enhanced Raman scattering vibration bands, 500, 1000, and 1585 cm(-1), associated with the cellular death dynamics. Detailed analysis indicated that the decrease in the 500 cm(-1) band did not correlate well with drug efficacy but could indicate death initiation. The time it takes for the relative intensity of either the 1000 or 1585 cm(-1) band ("SERS death" bands) to appear and increase to its maximum value after the injection of a known concentration of the drug can be related to the drug{\textquoteright}s efficacy. The inverse ratio, termed cell death enhancement factor, of these characteristic death times when using either band, especially the spectrally sharp band at 1000 cm(-1), gave the correct drug efficacy ratio as determined by the commonly used XTT cell viability assay method. These results strongly suggest the potential future use of this technique in determining the efficacy, dynamics, and molecular mechanisms of various drugs against different diseases.[on SciFinder (R)]},
	isbn = {1520-5126},
	author = {Austin, Lauren and Kang, Bin and El-Sayed, Mostafa A.}
}
@article {1348,
	title = {Surface Assembly and Plasmonic Properties in Strongly Coupled Segmented Gold Nanorods},
	journal = {Small},
	year = {2013},
	note = {MEDLINE AN 2013463112(Journal; Article; (JOURNAL ARTICLE))},
	month = {//},
	abstract = {An assembly strategy is reported such that segmented nanorods fabricated through template-assisted methods can be robustly transferred and tethered to a pre-functionalized substrate with excellent uniformity over large surface areas. After embedding the rods, sacrificial nickel segments were selectively etched leaving behind strongly coupled segmented gold nanorods with gaps between rods below 40 nm and as small as 2 nm. Hyper-spectral imaging is utilized to measure Rayleigh scattering spectra from individual and coupled nanorod elements in contrast to common bulk measurements. This approach discerns the effects of not only changing segment and gap size but also the presence of characteristic defects on the plasmonic coupling between closely spaced nanorods. Polarized hyper-spectral measurements are conducted to provide direct observation of the anisotropic plasmonic resonance modes in individual and coupled nanorods, which are close to those predicted by computer simulations for nanorods with ideal shapes. Some common deviations from ideal shape such as non-flat facets and asymmetric tails are demonstrated to result in the appearance of characteristic plasmon resonances, which have not been considered before. The large-scale assembly of coupled noble nanostructures with fine control over geometry and high uniformity provides means to strongly tune the scattering, absorption, and near-field plasmonic properties through the geometric arrangement of precisely controlled nanorod segments.[on SciFinder (R)]},
	isbn = {1613-6829},
	author = {Gupta, Maneesh K. and Konig, Tobias and Near, Rachel and Nepal, Dhriti and Drummy, Lawrence F. and Biswas, Sushmita and Naik, Swati and Vaia, Richard A. and El-Sayed, Mostafa A. and Tsukruk, Vladimir V.}
}
@article {1332,
	title = {Real-Time Molecular Imaging throughout the Entire Cell Cycle by Targeted Plasmonic-Enhanced Rayleigh/Raman Spectroscopy},
	journal = {Nano Letters},
	volume = {12},
	number = {10},
	year = {2012},
	note = {Times Cited: 0Kang, Bin Austin, Lauren A. El-Sayed, Mostafa A.},
	month = {Oct},
	pages = {5369-5375},
	abstract = {Due to their strong enhancement of scattered light, plasmonic nanoparticles have been utilized for various biological and medical applications. Here, we describe a new technique, Targeted Plasmonic-Enhanced Single-Cell Rayleigh/Raman Spectroscopy, to monitor the molecular changes of any cell-component, such as the nucleus, during the different phases of its full cell cycle by simultaneously recording its Rayleigh images and Raman vibration spectra in real-time. The analysis of the observed Raman DNA and protein peaks allowed the different phases of the cell cycle to be identified. This technique could be used for disease diagnostics and potentially improve our understanding of the molecular mechanisms of cellular functions such as division, death, signaling, and drug action.},
	isbn = {1530-6984},
	doi = {10.1021/nl3027586},
	author = {Kang, B. and Austin, Lauren and El-Sayed, M. A.}
}
@article {1330,
	title = {Small Molecule-Gold Nanorod Conjugates Selectively Target and Induce Macrophage Cytotoxicity towards Breast Cancer Cells},
	journal = {Small},
	volume = {8},
	number = {18},
	year = {2012},
	note = {Times Cited: 0Dreaden, Erik C. Mwakwari, Sandra C. Austin, Lauren A. Kieffer, Matthew J. Oyelere, Adegboyega K. El-Sayed, Mostafa A.},
	month = {Sep},
	pages = {2819-2822},
	isbn = {1613-6810},
	doi = {10.1002/smll.201200333},
	author = {Dreaden, E. C. and Mwakwari, S. C. and Austin, Lauren and Kieffer, M. J. and Oyelere, A. K. and El-Sayed, M. A.}
}
@article {1325,
	title = {Plasmonic Imaging of Human Oral Cancer Cell Communities during Programmed Cell Death by Nuclear-Targeting Silver Nanoparticles},
	journal = {Journal of the American Chemical Society},
	volume = {133},
	number = {44},
	year = {2011},
	note = {Times Cited: 13Austin, Lauren A. Kang, Bin Yen, Chun-Wan El-Sayed, Mostafa A.},
	month = {Nov},
	pages = {17594-17597},
	abstract = {Plasmonic nanoparticles (NPs) have become a useful platform in Medicine for potential uses in disease diagnosis and treatment. Recently, it has been reported that plasmonic NPs conjugated to nuclear targeting peptides cause DNA damage and apoptotic populations in cancer cells. In the present work, we utilized the plasmonic scattering property and the ability of nuclear-targeted silver nanoparticles (NLS/RGD-AgNPs) to induce programmed cell death in order to image in real-time the behavior of human oral squamous carcinoma (HSC-3) cell communities during and after the induction of apoptosis. Plasmonic live-cell imaging revealed that HSC-3 cells behave as nonprofessional phagocytes. The induction of apoptosis in some cells led to attraction of and their subsequent engulfment by neighboring cells. Attraction to apoptotic cells resulted in clustering of the cellular community. Live-cell imaging also revealed that,. as the initial,concentration of NLS/RGD-AgNPs. increases, the rate of self killing increases and the degree of attraction and clustering decreases. These results are discussed in terms of the proposed mechanism of cells undergoing programmed cell death.},
	isbn = {0002-7863},
	doi = {10.1021/ja207807t},
	author = {Austin, Lauren and Kang, B. and Yen, C. W. and El-Sayed, M. A.}
}
@article {1097,
	title = {Comparative study of photothermolysis of cancer cells with nuclear-targeted or cytoplasm-targeted gold nanospheres: continuous wave or pulsed lasers},
	journal = {Journal of Biomedical Optics},
	volume = {15},
	number = {5},
	year = {2010},
	note = {Huang, Xiaohua Kang, Bin Qian, Wei Mackey, Megan A. Chen, Po C. Oyelere, Adegboyega K. El-Sayed, Ivan H. El-Sayed, Mostafa A.},
	month = {Sep-Oct},
	abstract = {We conduct a comparative study on the efficiency and cell death pathways of continuous wave (cw) and nanosecond pulsed laser photothermal cancer therapy using gold nanospheres delivered to either the cytoplasm or nucleus of cancer cells. Cytoplasm localization is achieved using arginine-glycine-aspartate peptide modified gold nanospheres, which target integrin receptors on the cell surface and are subsequently internalized by the cells. Nuclear delivery is achieved by conjugating the gold nanospheres with nuclear localization sequence peptides originating from the simian virus. Photothermal experiments show that cell death can be induced with a single pulse of a nanosecond laser more efficiently than with a cw laser. When the cw laser is applied, gold nanospheres localized in the cytoplasm are more effective in inducing cell destruction than gold nanospheres localized at the nucleus. The opposite effect is observed when the nanosecond pulsed laser is used, suggesting that plasmonic field enhancement of the nonlinear absorption processes occurs at high localization of gold nanospheres at the nucleus. Cell death pathways are further investigated via a standard apoptosis kit to show that the cell death mechanisms depend on the type of laser used. While the cw laser induces cell death via apoptosis, the nanosecond pulsed laser leads to cell necrosis. These studies add mechanistic insight to gold nanoparticle-based photothermal therapy of cancer. (c) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3486538]},
	isbn = {1083-3668},
	doi = {10.1117/1.3486538},
	author = {Huang, Xiaohua and Kang, Bin and Qian, Wei and Mackey, M. A. and Chen, P. C. and Oyelere, A. K. and El Sayed, I.H. and El-Sayed, Mostafa 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 {1145,
	title = {Effect of plasmonic gold nanoparticles on benign and malignant cellular autofluorescence: A novel probe for fluorescence based detection of cancer},
	journal = {Technology in Cancer Research \& Treatment},
	volume = {6},
	number = {5},
	year = {2007},
	note = {El-Sayed, Ivan Huang, Xiaohua Macheret, Fima Humstoe, Joseph Oren Kramer, Randall El-Sayed, Mostafa},
	month = {Oct},
	pages = {403-412},
	abstract = {Due to the strong surface fields of noble metal nanoparticles, absorption and scattering of electromagnetic radiation is greatly enhanced. Noble metallic nanoparticles represent potential novel optical probes for simultaneous molecular imaging and photothermal cancer therapy using the enhanced scattering and absorption of light. Further, gold nanoparticles can affect molecular fluorescence via chemical, electronic, or photonic interactions. Live cells generate fluorescence due to intracellular and extracellular molecules. Differences in the biochemical composition between healthy and malignant cells can be exploited in vivo to help identify cancer spectroscopically. The interaction of gold nanoparticles with cellular autofluorescence has not yet been characterized. We hypothesized that gold nanoparticles delivered to live cells in vitro would alter cellular autofluorescence and may be useful as a novel class of contrast agent for fluorescence based detection of cancer. The fluorescence of two fluorophores that are responsible for tissue autofluorescence, NADH and collagen, and of two oral squamous carcinoma cell lines and one immortalized benign epithelial cell line were measured in vitro. Gold nanoparticles of different shapes, both spheres and rods, quenched the fluorescence of the soluble NADH and collagen. Reduction of NADH fluorescence was due to oxidation of NADH to NAD+ catalyzed by gold nanoparticles (results we previously published). Reduction of collagen fluorescence appears due to photonic absorption of light. Furthermore, a mean quenching of 12/8\% (p < 0.00050) of the tissue autofluorescence of cell suspensions was achieved in this model when nanospheres were incubated with the live cells. Gold nanospheres significantly decrease cellular autofluorescence of live cells under physiological conditions when excited at 280nm. This is the first report to our knowledge to suggest the potential of developing targeted gold nanoparticles optical probes as contrast agents for fluorescence based diagnoses of cancer.},
	isbn = {1533-0346},
	author = {El Sayed, I.H. and Huang, Xiaohua and Macheret, F. and Humstoe, J. O. and Kramer, R. and El-Sayed, Mostafa A}
}
@article {1155,
	title = {Using silica films and powders modified with benzophenone to photoreduce silver nanoparticles},
	journal = {Journal of Photochemistry and Photobiology a-Chemistry},
	volume = {181},
	number = {2-3},
	year = {2006},
	note = {Eustis, Susie Krylova, Galina Smirnova, Natalie Eremenko, Anna Tabor, Christopher Huang, Wenyu El-Sayed, Mostafa A.},
	month = {Jul},
	pages = {385-393},
	abstract = {Porous silica (SiO2 films and powders), modified with benzophenone (BP), facilitates the formation of stable sliver nanoparticles by taking advantage of the solid supported photosensitizer. The silica serves as a carrier for the BP into an aqueous solution and its subsequent removal. Benzophenone, bound to a silica film, was able to reduce silver ions to generate nanoparticles in solution, while silica powder with bound BP generates silver nanoparticles that are attracted to the silica. Silver nanoparticles are also fabricated in porous silica films by incorporating silver ions into the films before casting and then irradiating the film in a solution containing BP. From pH studies, it is concluded that the ketyl-radicals and anion-radicals of BP and IPA both take part in the reduction of silver ions. These synthetic studies provide a new photochemical reduction method by immobilizing the reactant on a silica surface allowing generation of silver nanoparticles in solution attached to powders or inside a film for catalytic applications or increased conductivity of silica films. (c) 2006 Elsevier B.V. All rights reserved.},
	isbn = {1010-6030},
	doi = {10.1016/j.jphotochem.2005.12.024},
	author = {Eustis, Susie and Krylova, G. and Smirnova, N. and Eremenko, A. and Tabor, C. E. and Huang, Wenyu and El-Sayed, Mostafa A}
}
@article {837,
	title = {Growth and fragmentation of silver nanoparticles in their synthesis with a fs laser and CW light by photo-sensitization with benzophenone},
	journal = {Photochemical \& Photobiological Sciences},
	volume = {4},
	year = {2005},
	pages = {154-159},
	publisher = {Royal Society of Chemistry},
	abstract = {The photo-sensitization synthetic technique of making silver nanoparticles using benzophenone is studied using both a laser and a mercury lamp as light sources. The power and irradiation time dependence of the synthesized nanoparticle absorption spectra and their size distribution [as determined by transmission electron microscopy (TEM)] are studied in each method and compared. In the laser synthesis, as either the laser power or the irradiation time increases, the intensity of the surface plasmon resonance absorption at 400 nm is found to increase linearly first, followed by a reduction of the red edge of the plasmon resonance absorption band. The TEM results showed that in the laser synthesis low powers and short irradiation times produce nanoparticles around 20 nm in diameter. Increasing the power or irradiation time produces a second population of nanoparticles with average size of 5 nm in diameter. These small particles are believed to be formed from the surface ablation of the large particles. The surface plasmon absorption band is found to be narrower when the nanoparticles are produced with laser irradiation. Throughout the exposure time with the CW lamp, the plasmon resonance absorption band of the particles formed first grows in intensity, then blue shifts and narrows, and finally red shifts while decreasing in intensity. The TEM results for lamp samples showed particle formation and growth, followed by small nanoparticle formation. The above results are discussed in terms of a mechanism in which, the excited benzophenone forms the ketal radical, which reduces Ag+ in solution and on the Ag nanoparticle surface. As the time of irradiation or the light energy increases the benzophenone is consumed, which is found to be the limiting reagent. This stops the formation of the normal large nanoparticles while their photo-ablation continues to make the small particles.},
	doi = {10.1039/B411488D},
	author = {Eustis, Susie and Krylova, G. and Eremenko, A. and Smirnova, N. and Schill, A. W. and El-Sayed, Mostafa A}
}
@article {838,
	title = {Propylene hydrogenation over cubic Pt nanoparticles deposited on alumina},
	journal = {BULLETIN-KOREAN CHEMICAL SOCIETY},
	volume = {25},
	year = {2004},
	pages = {843-846},
	publisher = {Korean Chemical Society},
	abstract = {Pt nanoparticles loaded on alumina through an impregnation at room temperature was prepared using K2PtCl4 and acrylic acid as capping material. Transmission electron microscopy showed that the deposited Pt particles indicate ca. 80\% cubic shapes with a narrow distribution of 8-10 nm in size. Propylene hydrogenation over the catalyst has been carried out to evaluate their catalytic performance by the values of activation energy. It is determined from the initial rate, reaction order, and rate constant and is found to be 9.7 {\textpm} 0.5 kcal/mol. This value has been discussed by comparing to those of encapsulated- and truncated octahedral Pt nanoparticles deposited on alumina, respectively, to study influence of the particle size and shape, and capping material used
on the activation energy.},
	isbn = {0253-2964},
	url = {http://www.journal.kcsnet.or.kr/main/j_search/j_abstract_view.htm?code=B040616\&qpage=j_search\&spage=b_bkcs\&dpage=ar},
	author = {Yoo, J. W. and Lee, S.M. and Kim, H.T. and El-Sayed, Mostafa A}
}
@article {839,
	title = {Shape control of platinum nanoparticles by using different capping organic materials},
	journal = {BULLETIN-KOREAN CHEMICAL SOCIETY},
	volume = {25},
	year = {2004},
	pages = {395},
	abstract = {No Abstract},
	keywords = {Cube, Nanoparticle, Platinum, Transmission electron microscopy, Truncated octahedra},
	url = {http://newjournal.kcsnet.or.kr/main/j_search/j_abstract_view.htm?code=B040315\&qpage=j_search\&spage=b_bkcs\&dpage=ar},
	author = {Yoo, J. W. and Lee, S.M. and Kim, H.T. and El-Sayed, Mostafa A}
}
@article {1254,
	title = {Low-temperature retinal photoisomerization dynamics in bacteriorhodopsin},
	journal = {Journal of Physical Chemistry B},
	volume = {102},
	number = {13},
	year = {1998},
	note = {Logunov, SL Masciangioli, TM Kamalov, VF El-Sayed, MA},
	month = {Mar},
	pages = {2303-2306},
	abstract = {Retinal photoisomerization dynamics are studied at both room temperature and 20 K in wild-type bacteriorhodopsin using femtosecond pulses. We were able to resolve the decay at 20 K into two components with the dominant component having a similar lifetime to that observed at room temperature. This strongly suggests that the retinal lifetime at physiological temperature is barrierless. The minor, low-temperature long-lived component is discussed in terms of previous results obtained for fluorescence and transient absorption with lower time resolution, and the origin of this component is discussed in terms of low-temperature glass heterogeneity.},
	isbn = {1089-5647},
	doi = {10.1021/jp972921a},
	author = {Logunov, Stephan L. and Masciangioli, Tina M. and Kamalov, Valey F. and El-Sayed, Mostafa A}
}
@article {868,
	title = {Electron Dynamics of Passivated Gold Nanocrystals Probed by Subpicosecond Transient Absorption Spectroscopy},
	journal = {The Journal of Physical Chemistry B},
	volume = {101},
	year = {1997},
	note = {doi: 10.1021/jp962923f},
	month = {1997},
	pages = {3713 - 3719},
	publisher = {American Chemical Society},
	abstract = {The electronic dynamics of gold nanocrystals, passivated by a monolayer of alkylthiol(ate) groups, were studied by transient spectroscopy after excitation with subpicosecond laser pulses. Three solution-phase gold samples with average particle size of 1.9, 2.6, and 3.2 nm with size distribution less than 10\% were used. The photoexcitation in the intraband (surface plasmon region) leads to the heating of the conduction electron gas and its subsequent thermalization through electron?electron and electron?phonon interaction. The results are analyzed in terms of the contribution of the equilibrated ?hot? electrons to the surface plasmon resonance of gold. A different spectral response was observed for different sizes of gold nanoparticles. The results were compared to the dynamics of the large (30 nm diameter) gold nanocrystals colloidal solution. The size-dependent spectral changes are attributed to the reduction of the density of states for small nanoparticles. The observed variation in the kinetics of the cooling process in gold nanoparticles with changing the laser intensity is attributed to the temperature dependence of the heat capacity of the electron gas.The electronic dynamics of gold nanocrystals, passivated by a monolayer of alkylthiol(ate) groups, were studied by transient spectroscopy after excitation with subpicosecond laser pulses. Three solution-phase gold samples with average particle size of 1.9, 2.6, and 3.2 nm with size distribution less than 10\% were used. The photoexcitation in the intraband (surface plasmon region) leads to the heating of the conduction electron gas and its subsequent thermalization through electron?electron and electron?phonon interaction. The results are analyzed in terms of the contribution of the equilibrated ?hot? electrons to the surface plasmon resonance of gold. A different spectral response was observed for different sizes of gold nanoparticles. The results were compared to the dynamics of the large (30 nm diameter) gold nanocrystals colloidal solution. The size-dependent spectral changes are attributed to the reduction of the density of states for small nanoparticles. The observed variation in the kinetics of the cooling process in gold nanoparticles with changing the laser intensity is attributed to the temperature dependence of the heat capacity of the electron gas.},
	isbn = {1520-6106},
	url = {http://dx.doi.org/10.1021/jp962923f},
	author = {Logunov, Stephan L. and Ahmadi, Temer S. and El-Sayed, Mostafa A and Khoury, J. T. and Whetten, R. L.}
}
@article {864,
	title = {Optical rotation of the second harmonic radiation from retinal in bacteriorhodopsin monomers in Langmuir-Blodgett film: evidence for nonplanar retinal structure.},
	journal = {Biophysical journal},
	volume = {73},
	year = {1997},
	month = {1997 Dec},
	pages = {3164-70},
	abstract = {We observed optical rotation of the plane of polarization of the second harmonic (SH) radiation at 532 nm (in resonance with the retinal absorption) generated in reflection geometry in Langmuir-Blodgett film of bacteriorhodopsin (bR). The analysis of the experimental data showed that this effect arises from the nonvanishing contribution of the antisymmetrical part of the hyperpolarizability tensor. This requires that the dipole moment of the resonant electronic transition, the change of the dipole moment upon electronic excitation, and the long axis of the retinal not be coplanar. Such conditions are satisfied only if the retinal has a nonplanar geometry, a conclusion that could lend support to the heterogeneity model of the origin of the biphasic band shape of the linear CD spectrum of the retinal in bR. On the basis of our theoretical analysis, we were able to estimate the angle between the induced dipole moment and the plan that contains the long axis of the chromophore and the transition dipole moment of the retinal absorption.},
	keywords = {Bacteriorhodopsins, Biophysical Phenomena, Biophysics, Circular Dichroism, Molecular Structure, Optics and Photonics, Retinaldehyde, Spectrophotometry},
	issn = {0006-3495},
	doi = {10.1016/S0006-3495(97)78342-5},
	author = {Volkov, V. V. and Svirko, Y P and Kamalov, Valey F. and Song, Li and El-Sayed, Mostafa A}
}
@article {1270,
	title = {Calcium and Magnesium Binding in Native and Structurally Perturbed Purple Membrane},
	journal = {The Journal of Physical Chemistry},
	volume = {100},
	year = {1996},
	note = {doi: 10.1021/jp952951i},
	month = {1996},
	pages = {929 - 933},
	publisher = {American Chemical Society},
	abstract = {The number and identity of the metal cations bound to wild-type bacteriorhodopsin (bR) are determined by using inductively coupled plasma mass spectrometry (ICP-MS) and ICP emission techniques. The results indicate that there at ≈2 total Ca2+ and Mg2+ per bR molecule with a ratio of ≈3:1 Ca2+ to Mg2+. This observed ratio is found to agree with the calculated ratio using previously determined binding constants for the two high affinity sites of Ca2+ to deionized bR (Zhang; et al. Biophys. J. 1992, 61, 1201). This suggests that the high-affinity binding sites in deionized bR are similar to those in native bR. Structural perturbation of the native membrane by cleavage of the C-terminus decreases the number of ions per bR to 1.4. The observed ratio of total ions in this sample to total ions in bR is found to agree with that calculated using known binding constants for each. The results on the number of metal cations/bR and their ratio in bacterio-opsin agrees with the calculated number using previously observed binding constants in deionized bO (Yang; et al. Biophys J., in press) only if one assumes that the second high-affinity site (not the first) is removed by retinal removal. Removal of 75\% of the lipids from the purple membrane is found to greatly reduce the number of metal cations from 2 to 0.16. This suggest that if metal cations are in the two high-affinity sites (which are the only type of binding sites evident in our native bR sample), the removal of lipids, known to change the protein tertiary structure, changes also the metal ion binding sites.The number and identity of the metal cations bound to wild-type bacteriorhodopsin (bR) are determined by using inductively coupled plasma mass spectrometry (ICP-MS) and ICP emission techniques. The results indicate that there at ≈2 total Ca2+ and Mg2+ per bR molecule with a ratio of ≈3:1 Ca2+ to Mg2+. This observed ratio is found to agree with the calculated ratio using previously determined binding constants for the two high affinity sites of Ca2+ to deionized bR (Zhang; et al. Biophys. J. 1992, 61, 1201). This suggests that the high-affinity binding sites in deionized bR are similar to those in native bR. Structural perturbation of the native membrane by cleavage of the C-terminus decreases the number of ions per bR to 1.4. The observed ratio of total ions in this sample to total ions in bR is found to agree with that calculated using known binding constants for each. The results on the number of metal cations/bR and their ratio in bacterio-opsin agrees with the calculated number using previously observed binding constants in deionized bO (Yang; et al. Biophys J., in press) only if one assumes that the second high-affinity site (not the first) is removed by retinal removal. Removal of 75\% of the lipids from the purple membrane is found to greatly reduce the number of metal cations from 2 to 0.16. This suggest that if metal cations are in the two high-affinity sites (which are the only type of binding sites evident in our native bR sample), the removal of lipids, known to change the protein tertiary structure, changes also the metal ion binding sites.},
	isbn = {0022-3654},
	doi = {doi: 10.1021/jp952951i},
	url = {http://dx.doi.org/10.1021/jp952951i},
	author = {Griffiths, Jennifer A. and King, John and Yang, Difei and Browner, Richard and El-Sayed, Mostafa A}
}
@article {1269,
	title = {Homogeneous Line Width of the Different Vibronic Bands of Retinal Absorption in Bacteriorhodopsin by the Hole-Burning Technique},
	journal = {The Journal of Physical Chemistry},
	volume = {100},
	year = {1996},
	note = {doi: 10.1021/jp952971k},
	month = {1996},
	pages = {2762 - 2765},
	publisher = {American Chemical Society},
	abstract = {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.},
	isbn = {0022-3654},
	doi = {doi: 10.1021/jp952971k},
	url = {http://dx.doi.org/10.1021/jp952971k},
	author = {Kamalov, Valey F. and Masciangioli, Tina M. and El-Sayed, Mostafa A}
}
@article {873,
	title = {Picosecond Electronic Relaxation in CdS/HgS/CdS Quantum Dot Quantum Well Semiconductor Nanoparticles},
	journal = {The Journal of Physical Chemistry },
	volume = {100},
	year = {1996},
	note = {doi: 10.1021/jp953708m},
	month = {1996},
	pages = {6381 - 6384},
	publisher = {American Chemical Society},
	abstract = {Subpicosecond photoexcitation of CdS/HgS/CdS quantum dot quantum well nanoparticles at wavelengths shorter than their interband absorption (390 nm) leads to a photobleach spectrum at longer wavelengths (440?740 nm). The photobleach spectrum changes and its maximum red-shifts with delay time. These results are explained by the rapid quenching of the initially formed laser-excited excitons by two types of energy acceptors (traps); one is proposed to be due to CdS molecules at the CdS/HgS interface, and the other trap is that present in the CdS/HgS/CdS well. The results of the excitation at longer wavelengths as well as the formation and decay of the bleach spectrum at different wavelengths support this description.Subpicosecond photoexcitation of CdS/HgS/CdS quantum dot quantum well nanoparticles at wavelengths shorter than their interband absorption (390 nm) leads to a photobleach spectrum at longer wavelengths (440?740 nm). The photobleach spectrum changes and its maximum red-shifts with delay time. These results are explained by the rapid quenching of the initially formed laser-excited excitons by two types of energy acceptors (traps); one is proposed to be due to CdS molecules at the CdS/HgS interface, and the other trap is that present in the CdS/HgS/CdS well. The results of the excitation at longer wavelengths as well as the formation and decay of the bleach spectrum at different wavelengths support this description.},
	isbn = {0022-3654},
	url = {http://dx.doi.org/10.1021/jp953708m},
	author = {Kamalov, Valey F. and Little, Reginald and Logunov, Stephan L. and El-Sayed, Mostafa A}
}
