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Project Theme 14: Femtosecond Near-Field Optical Microscopy of Photoexcitable Biointerfaces
Faculty Advisors:
Zimmerman, Bartynski (PA); Chabal (BME), Castner (CCB)
Crossdisciplinary Bridging:
Surface Science, Physics, Physical Chemistry, Biophysics, Microscopy
Many organisms utilize photoactive proteins in photoreceptors or photosynthetic light harvesting complexes to convert light to chemical energy. Such proteins could be functionalized on substrates to serve as biomimetic implants (e.g., for the retina), optical biosensors, memory elements for optical computers, or as models for renewable energy biotechnologies. This study is designed to elucidate the photoexcitation and energy transfer mechanisms of model photoactive proteins, such as bacteriorhodopsin. The chromophore of bacteriorhodopsin consists of the conjugated molecule retinal, which is covalently bound to the backbone of the photoactive protein through a protonated Schiff-base linkage. An essential aspect of the light harvesting process is a series of electronic and conformational changes that can be tracked spectroscopically (57, 58). However, the electronic and geometrical structures of the spectroscopically distinct intermediate species are only now beginning to emerge, and their functional role in the proton pumping process is completely understood.
We will use a novel microscope currently under development at Rutgers to study the photoexcitation and energy transfer dynamics of the individual bacteriorhodopsin molecules, as well as its isolated retinylidine chromophore, anchored to a suitable substrate (e.g. SiO2 or hydrogen terminated Si(111)). The instrument is based on an apertureless scanning near-field optical microscope (ASNOM), in which light scattering from a sharp metal tip scanned across the substrate provides images with nanometer spatial resolution. Femtosecond laser pulses will initiate the photochemical reaction cycle, and resulting electronic and conformational changes will be optically imaged with time-delayed probe pulses. With this optical pump-probe method we will obtain images for given values of the delay time between pump and probe pulses. Images of increasing delay time can then be assembled as actual movies of the dynamical process with femtosecond time resolution.
The ASNOM being developed in our lab will have the capability to detect and image major photoinduced conformational changes, as well as to follow the electronic excitation and energy transfer dynamics on a femtosecond time scale. Structural characterization of photoexcitable biointerfaces will be performed by infrared spectroscopy, and photo-induced dynamics will be evaluated using femtosecond fluorescence, absorption, and Raman spectroscopies.
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| Major Events |
IRIF:Megan Anderson Fri., 12/11 in BME-122, 12-1 pm
Enhanced Survival of Progeny of Neural Stem Cells in Response to Trace Eyeblink Conditioning
IRIF:Andrew LHuillier Thurs., 11/19 in BME-122, 12-1pm
Mesenchymal Stem Cell Mediated Immunosuppression and IDO Metabolites
RESCHEDULED: Bioindustry Ethics Luncheon Part II w/ David Finegold (IGERT Fellows ONLY) 11/5/09
Part II of the Ethics Luncheon will be rescheduled to the Spring semester IRIF schedule.
IRIF:Dr. Debu Banerjee 10/22 in BME-122, 12-1 pm
Therapeutic applications of bone marrrow derived Mesenchmal stem cells
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Congratulations!
IGERT Fellows Aaron Carlson and Mohamed Sadik took 1st and 3rd place (respectively) in the Poster Presentations at the 3rd Annual NJ Stem Cell Symposium held Thursday, September 24, 2009. Aaron Carlson's poster was titled “3-D Electrospun Polymer Scaffolds Promote Human Embryonic Stem Cell Self-Renewal and Controlled Organization". Mohamed presented “Electroporation-Mediated Molecular Delivery”. Jonathan Davilla took 2nd place with “Identification of Biologically Functional microRNAs in Human ESCs by Ago2 Immunoprecipitation and Sequencing”. The keynote address was delivered by Hakim Djaballah, PhD of the Memorial Sloan Kettering Cancer Center.
Congratulations to Professor Ki-Bum Lee, Stem Cell IGERT Faculty in Chemistry and Chemical Biology, who is the recipient of the NIH Director’s New Innovator award, 2009.
The NIH Director's New Innovator Award program is designed specifically to support unusually creative early stage investigators with highly innovative research ideas at an early stage of their career.
IGERT fellow wins award:
Congratulations to IGERT fellow Nicole Plourde who was recipient of the 2009 Schering-Plough Innovation Award. She was presented with an awards plaque and a check for $5000 at a ceremony on Thursday, April 16th.
Chris Ricupero featured on Epigenie interview
Follow link here for full interview.
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