Microscopy

Researchers at the University of Illinois have developed coherently scattering probes to allow imaging of intracellular structures at nanometer spatial resolution using far-field instruments. The probes can acquire data in a multiplex fashion. This technology circumvents the temporal multiplexing of conventional PALM/STORM microscopy. Images are acquired quickly with high signal-to-noise ratio, making it applicable for dynamic biological samples. 

Professor Dana Dlott and Natalia Garcia Rey have designed a spectra-electrochemical cell that is user and environmental friendly. The material used is chemically resistant for cleaning and electrochemical experiments. Previous designs presented a complicated assembly with many different parts, large volume, and a liquid gap between the window and the electrode that could not be controlled. 

Their findings show how important it is to have control of the gap for the ultrafast spectroscopic analysis and for understanding of the electrochemical reactions occurring on the electrolyte-electrode. This design also allows one to move the electrode sample to refresh the solution and repeat the experiment, setting the sample back to the same position with micrometer precision, which is very important in laser experiments and for comparing between results. The design uses commercial electrodes that can be polished, electrochemically cleaned and assembled in the cell. Previous designs use evaporated metallic thin fill on glass, increasing the cost of each experiment, and limitations of the electrodes to study (ie. single crystals). In addition, this design does not require a special sample holder; it can fit a commercially available 2" diameter mirror mount.

This technology is a novel asymmetrical microstructure capable of generating tunable photonic nanojets (PNJ) allowing super-resolution microscopy. The microstructure has tunable properties allowing generation of multiple PNJs, from ultra-narrow for super-resolution to ultra-long for detection of nanoparticles in biological samples. This technology opens the door for applications beyond super-resolution imaging, such as data retrieval from ultra-high density optical storage as well as nanolithography.

Dr. Kimani Toussaint and Mr. Chukwuemeka Okoro have developed a Second-harmonic Patterned Polarization-Analyzed Reflection Confocal (SPPARC) microscopy technique combining confocal microscopy, second harmonic generation (SHG) microscopy and Mueller matrix polarimetry. SPPARC has a strong potential to more accurately and quantitatively describe 3D microstructural changes in collagen-rich samples as well as non-collagenous extra-fibrillary matrix regions. It also provides a framework for 3D label-free SHG-patterned quantification of collagen to more accurately monitor sensitive changes. For more information, please contact the Office of Technology Management at otm@illinois.edu.