This project will develop a super resolution pump-probe modulation (PPM) microscope to image non-fluorescent molecules. Imaging has become an important tool in biomedical research and clinical prognosis and treatment. Optical imaging systems, particularly fluorescence microscopy, have been extensively used in biomedical research. Recently, stimulated emission depletion (STED) microscopy has achieved nanometer resolution using point-spread function (PSF) engineering techniques to break the diffraction limit. All these super resolution techniques are based on molecular fluorescence with most applications requiring tagging exogenous fluorophores onto targeted molecules. However, the labeling process can alter the activity or localization of the molecules. Recently pump-probe microscopy demonstrated its ability to image non-fluorescent molecules by detecting the energy transitions between different molecular energy levels when two femtosecond/picosecond laser pulses are interacting with the molecules. The common feature of the pump-probe microscope and the STED microscope is that both modalities use two laser beams to excite and then to probe or deplete the molecules. The innovation of this proposal is developing a pump-probe modulation (PPM) microscope that combines the PSF engineering method used in STED microscopy and the pump-probe method to achieve the goal of imaging non-fluorescent molecules with nanometer resolution. There are two specific aims in this grant application: (1) Develop a pump-probe modulation microscope based on stimulated emission and ground state depletion that can image gold nanorods and Atto612Q molecules with super resolution;and (2) Image dopamine in live Drosophila brain tissue with two-photon excitation PPM microscopy.

Public Health Relevance

The development of such an innovative pump-probe optical imaging modality will greatly increase our ability to detect, visualize and quantify non-fluorescen molecules at nanometer resolution with high sensitivity, which may give completely new insights into the physical relationships between molecular components in biomedical research.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Pilot Research Project (SC2)
Project #
1SC2GM103719-01A1
Application #
8741867
Study Section
Special Emphasis Panel (ZGM1-TWD-3 (SC))
Program Officer
Flicker, Paula F
Project Start
2014-08-01
Project End
2017-04-30
Budget Start
2014-08-01
Budget End
2015-04-30
Support Year
1
Fiscal Year
2014
Total Cost
$144,880
Indirect Cost
$44,880
Name
University of Texas El Paso
Department
Physics
Type
Schools of Arts and Sciences
DUNS #
132051285
City
El Paso
State
TX
Country
United States
Zip Code
79968