Vertes Research Group

Welcome

The scientific interests in the Vertes Research Group span from fundamental studies in analytical and physical chemistry to the development of new technologies for biomedical analysis. Recent accomplishments include the discovery of photonic ion sources based on columnar nanostructures, the introduction of a new ambient ion source called laser ablation electrospray ionization (LAESI), metabolic imaging of biological tissues under native conditions and the in situ mass spectrometric analysis of single cells.

Research highlights

1 - Laser induced silicon microcolumn arrays (LISMA) exhibit nanophotonic properties and unique fragmentation patterns that are adjustable by the laser fluence, and simultaneously produce high and low energy fragments.
2 - Laser ablation electrospray ionization (LAESI) is a new atmospheric pressure ion source for mass spectrometry. LAESI enables the direct analysis tissues, cells and other water containing samples.
3 - Silicon nanopost arrays (NAPA) can be tailored to exhibit resonant ion production. Ion yields from posts with subwavelength diameter show sharp resonances at high aspect ratios.
4 - Phase Doppler anemometry reveals that droplet size and velocity distributions in electrosprays are strongly dependent on the spraying mode that, in turn, is determined by the liquid flow rate and the spray voltage.
5 - Laser ablation electrospray ionization (LAESI) mass spectromtry enables the atmospheric pressure molecular imaging of biological tissues. The LAESI image of a rat brain coronal section shows the distribution of specific lipids.
7 - Nanopost array (NAPA) chips with different periodicities on a silicon wafer exhibit unique optical properties. Excited by laser radiation, they behave as nanophotonic ion sources.
8 - Single cell analysis by laser ablation electrospray ionization (LAESI) mass spectromtry produces rich spectra with over 100 ionic species. Numerous metabolites and lipids can be identified.
9 - Fast photography of electrospray mensci reveals the relationship between spraying modes and ion production in electrospray ionization. Dramatic changes in the droplet size distributions result from the various ejection and breakup mechanisms observed.

Latest News

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Open positions. Graduate student (Ph.D.) and undergraduate research positions are available in the following research areas: a/ Fundamental studies and applications of laser desorption ionization based on nanostructures. b/ Laser ablation electrospray ionization mass spectrometry for biomedical analysis and imaging. c/ Single cell analysis by mass spectrometry. Contact Professor Vertes for details at the vertes@gwu.edu e-mail address.
Protea press release hits the news. 9-8-2010 Following the press release by Protea Biosciences, Inc., to commercilaize our LAESI invention, the news hit the internet. Over 50 web sites reported on the announcement. Beyond the US sites, there were reports in France, Germany, Italy, The Netherlands, Finland and Japan. German, French and Dutch translations were also found. Among the better known sites were: Bloomberg, CNBC, Drug Discovery and Development, Forbes, Genetic Engineering & Biotechnology News, MSNBC, Reuters, Spiegel, TD Ameritrade, The Medical News, and Yahoo! Finance.
Protea announces LAESI commercialization . 9-8-2010 Protea Biosciences, Inc., announces the commercialization of the laser ablation electrospray ionization (LAESI) technology developed in the Vertes Laboratory. LAESI enables the direct analysis of water containing samples, e.g., aqueous solutions, biological tissues and cells, at atmospheric pressure.
Bioanalysis reports on mouse brain analysis . 3-17-2010 The March 2010 issue of the British journal "Bioanalysis" published by the Future Science Group reported on our mouse brain analysis work. The project had been carried out in collaboration with colleagues at the Children's National Medical Center in Washington, DC, and the results were reported in the journal Analyst.
Biophotonics reports on single cell analysis bt LAESI . The January, 2010, issue of Biophotonics magazine reported on our single cell analysis work. The interview focused on the application of laser ablation in single cell analysis, including molecular imaging based on single cells as pixels. The report is available online at: http://photonics.com/Article.aspx?AID=41135.

Recognitions

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Jessica Stolee receives 2010-2011 ARCS award. 10-21-2010 Jessica Stolee, a graduate student in the group, received the Carleen Sims Endowment Fellowship from the Achievement Rewards for College Scientists (ARCS) Foundation. Jessica develops new tools for the analysis of single cells and small cell populations. This is her second ARCS Foundation award.
Guest co-editing of Appl. Phys. A Special Issue. Boris Luk'yanchuk and Akos Vertes co-edited a Special Issue of the journal Applied Physics A. The October 2010 Special Issue was dedicated to "Laser Ablation: Fundamentals" and contained 37 articles based on presentations at the 10th International Conference on Laser Ablation, 2009, Singapore.
2010 Fassel Lecture in Analytical Chemistry . On April 2, 2010, at the Iowa State University, Prof. Akos Vertes delivered the 20th Annual Velmer A. Fassel Lecture in Analytical Chemistry. His talk entitled "Tissue Imaging and Single Cell Analysis by LAESI Mass Spectrometry" discussed the utility of this new method for the direct identification of metabolites and lipids at atmospheric pressure.
Jennifer Day receives CSW award . 2-11-2010 Jennifer Day, an undergraduate in the group, received the College Chemistry Achievement Award from The Chemical Society of Washington, the local chapter of the American Chemical Society. Jennifer's research focused on exploring metabolic differences between stem cells and differentiated cells in plants using LAESI mass spectrometry.
First Prize at COLA '09 in Singapore . 11-27-2009 Our poster entitled "Nanopost arrays as photonic ion sources for soft laser desorption ionization" presented by Bennett Walker, a graduate student in the group, won the First Prize for posters at the 10th International Conference on Laser Ablation (COLA 2009). The meeting was held in Singapore.

Latest articles

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121/ J. A. Stolee, B. N. Walker, Y. Chen and A. Vertes, "Nanophotonic Ion Sources," in: International Symposium on High Power Laser Ablation 2010, C. R. Phipps (ed), AIP Conf. Proc. 1278, 2010, 98-110.
120/ P. Sripadi, B. Shrestha, R. L. Easley, L. Carpio, K. Kehn-Hall, S. Chevalier, R. Mahieux, F. Kashanchi and A. Vertes, "Direct Detection of Diverse Metabolic Changes in Virally Transformed and Tax-expressing Cells by Mass Spectrometry," PLoS ONE, 2010, 5, e12590.
119/ P. Nemes and A. Vertes, "Atmospheric-pressure Molecular Imaging of Biological Tissues and Biofilms by LAESI Mass Spectrometry," J. Visualized Experiments, 2010, 43, http://www.jove.com/index/details.stp?id=2097.
Download a PDF of the protocol.
118/ B. Shrestha and A. Vertes, “Direct Analysis of Single Cells by Mass Spectrometry at Atmospheric Pressure,” J. Visualized Experiments, 2010, 43, http://www.jove.com/index/details.stp?id=2144.
Download a PDF of the protocol.
117/ C. H. Stephens, B. Shrestha, H. R. Morris, M. E. Bier, P. M. Whitmore and A. Vertes, “Minimally invasive monitoring of cellulose degradation by desorption electrospray ionization and laser ablation electrospray ionization mass spectrometry,” Analyst, 2010, 135, 2434-2444. Supplementary material.
116/ B. N. Walker, J. A. Stolee, D. L. Pickel, S. T. Retterer and A. Vertes, “Assessment of Laser-Induced Thermal Load on Silicon Nanostructures Based on Ion Desorption Yields,” Appl. Phys. A, 2010, 101, 539-544.
115/ B. Shrestha, P. Nemes and A. Vertes, “Ablation and analysis of small cell populations and single cells by consecutive laser pulses,” Appl. Phys. A, 2010, 101, 121-126.
114/ B. N. Walker, J. A. Stolee, D. L. Pickel, S. T. Retterer and A. Vertes, "Tailored Silicon Nanopost Arrays for Resonant Nanophotonic Ion Production," J. Phys. Chem. C, 2010, 114, 4835-4840.
113/ B. Shrestha, P. Nemes, J. Nazarian, Y. Hathout, E. P. Hoffman and A. Vertes, “Direct analysis of lipids and small metabolites in mouse brain tissue by AP IR-MALDI and reactive LAESI mass spectrometry,” Analyst, 2010, 135, 751-758. Supplementary material.
112/P. Nemes, A. S. Woods and A. Vertes, “Simultaneous Imaging of Small Metabolites and Lipids in Rat Brain Tissues at Atmospheric Pressure by Laser Ablation Electrospray Ionization Mass Spectrometry,” Anal. Chem., 2010, 82, 982-988. Supporting information.
111/ J. A. Stolee, Y. Chen and A. Vertes, "High-Energy Fragmentation in Nanophotonic Ion Production by Laser-Induced Silicon Microcolumn Arrays," J. Phys. Chem. C, 2010, 114, 5574-5581.