Schweikert Research Group

Selected Publications

S. V. Verkhoturov, M. J. Eller, R. D. Rickman, S. Della-Negra and E. A. Schweikert, Single Impacts of C60 on Solids: Emission of Electrons, Ions and Prospects for Surface Mapping, J. Phys. Chem. C, 2010, 114 (12), 5637–5644 

V. T. Pinnick, S. V. Verkhoturov, L. Kaledin, Y. Bisrat and E. A. Schweikert, Molecular Identification of Individual Nano-Objects, Anal. Chem.,  2009, 81 (18), 7527–7531

S. Rajagopalachary, S. V. Verkhoturov and E. A. Schweikert, Characterization of Individual Ag Nanoparticles and Their Chemical Environment, Anal. Chem., 2009, 81 (3),  1089–1094

V. Pinnick, S. Rajagopalachary, S. V. Verkhoturov, L. Kaledin, E. A. Schweikert, Characterization of Individual Nano-Objects by Secondary Ion Mass Spectrometry, Analyt. Chem., 2008, 80, 9052-9057

C. Guillermier, S. Della Negra, E. A. Schweikert, A. Dunlop, G. Rizza, Emission of Molecular Fragments Synthesized in Hypervelocity Nanoparticle Impacts, Int. J. Mass Spectrom., 2008, 275, 86-90.

Rajagopalachary, S.; Verkhoturov, S.V.; Schweikert, E.A. Examination of Nanoparticles via Single Large Cluster Impacts Nano Letters, in Press, 2008.

Members

Professor - Department of Chemistry
Director, Center for Chemical Characterization and Analysis
(979) 845-2341
schweikert@mail.chem.tamu.edu

Emile Schweikert is concerned with the development of novel instrumentation, techniques and data acquisition/analysis schemes for the characterization of solid surfaces. The technique of choice is secondary ion mass spectrometry with two key innovations: (a) surface bombardment is with keV polyatomic and cluster projectiles (e.g., (CsI)Cs+, C60+, Au4004+) to maximize the emission of secondary ions; the experiments are run in the event-by-event bombardment-detection mode (each projectile impact and its corresponding ejecta are observed individually), thus allowing to detect secondary icons from molecules colocated within the nanometric volume perturbed by a single projectile impact. The goal of Schweikert's research group is to develop surface analysis methodology to the level where zeptomole (10-21 mole) quantities of molecules can be localized and identified. The enhanced chemical vision is critical for localizing bioactive substances, understanding the formation of surface structures and the mechanism of catalytic processes.

 

Chen, Li-Jung
(979) 845-8156

ljchen@mail.chem.tamu.edu

I am originally from Taiwan and received my Bachelor degree in chemistry from National Chiao-Tung Unversity (Hsinchu, Taiwan) at 2002 and Master in chemical engineering from National Tsing-Hua University (Hsinchu, Taiwan) at 2004. Before joined TAMU, I worked at National Synchrotron Radiation Research Center as a research assistant and United Microeletronics Corporation Company as a semiconductor process and integration engineer. In 2006, I enrolled in chemistry at Texas A&M University and joined the Schweikert s research group. My current research focuses on using the cluster ToF-SIMS running in the event-by-event bombardment/detection to develop a methodology to characterize and quantify the number of AuNPs-antibody conjugates labeled on cells, to differentiate biological species from complexed surfaces, and to image patterned bio-complexes with a label-free approach. 

 

DeBord, John D.
(979) 845-8156
jdebord@mail.chem.tamu.edu

I received a B.S. in Chemistry from Campbell University (Buies Creek,  North Carolina) in 2007.  After graduation I worked for a year at the BASF Agricultural Products Research and Development Facility in Research Triangle Park, North Carolina.  In the summer of 2008 I joined the Schweikert lab.  One project I have completed is the development of an improved multiple anode detector for incorporation into our Secondary Ion Mass Spectrometry (SIMS) instruments.  This new detector has improved our detection efficiency by an order of magnitude.  I worked with Marcus Sidhartharaja on the development of an alternative sample preparation technique for laser desorption ionization mass spectrometric imaging using gold nanoparticles (NPs) to increase signal response.  Typically the NPs are deposited as a solution but this preparation is not conducive to MS imaging because it can result in delocalization of the analytes.  Our work has resulted in a solution free technique which utilizes a pneumatic delivery system to deposit the NPs.   Another project in the works is the development of a SIMS instrument capable of atmospheric pressure ionization.  The ability to analyze samples under ambient conditions will allow us to study biological samples in their natural forms as opposed to the dehydrated forms required for vacuum analysis.

 

Eller, Michael
(979) 845-2344
meller@mail.chem.tamu.edu

I am from Stillwater Minnesota and for undergrad I attended Iowa State University receiving a B.S. in Chemistry in 2007. In the fall of 2007 I joined the Schweikert research group. I currently work on the development of our Positional Mass Spectrometer which localizes individual C60 impacts. Related to this is I also have helped to develop a technique that investigates the electron emission from individual C60 impacts on different surfaces. Currently I am working on mapping drugs and nano particles in cells and tissues.

Liang, Chao-Kai  
(979) 845-8156
 chao-kai.liang@mail.chem.tamu.edu

I am from Taipei, Taiwan and received my Bachelor degree in chemistry from National Taiwan University in 2007, doing organic synthesis. I entered Texas A&M Univ. in Fall 2009 and joined the Schweikert research group in Spring 2010. In my first year, I took courses, taught freshman chem lab, and finished the cume exams. My research is going to focus on trace components analysis and sample preparation for analysis by SIMS.

 

Fernandez-Lima,
(979) 845-8156
ffernandez@mail.chem.tamu.edu

Francisco A Fernandez-Lima
Post-doctoral researcher, Texas A&M, Depts of Chemistry and Biology,
NIH Pathway to Independence Award (K99/R00): development of nanometer probes for mass spectrometry based imaging with enhanced sub-micrometer lateral resolution of molecular yield emission and post-ionization, gas-phase separation for studies at the single cell and sub-cellular level of native biological surfaces.

http://tamu.academia.edu/FranciscoAFernandezLima

 

Verkhoturov, Stanislav
(979) 845-2344
verkhoturov@mail.chem.tamu.edu

Research Interests:
Surface analysis via mass spectrometry (coincidence method) of nanoobjects deposited on surface (cluster, nanoparticles, deposited organic molecules and cells).

Development of new method for sub-nano-scale analysis of surfaces via radioactive K-capture decay. Fabrication of self-assembled mono/bilayer of organic molecules with embedded radioactive atoms.

 

Group Photo: