Breakthrough photo-thermal modulation based IR microscope for sub-micron characterization of cellular metabolism and chemical processes within cells

Label-free sub-micron chemical imaging and spectroscopy has long been sought for visualization of biomolecules and materials in complex living systems- As stated in the DOE’s Biological and Environmental Research Program Office website, Bioimaging and measurement technologies that can resolve multiple key metabolic processes over time within or among cells will act as a crucial bridge toward linking molecular-scale information to whole-cell, systems-level understanding- Although Raman spectroscopy has made some inroads here, it is generally accepted by most Raman practitioners that the two major problems faced by Raman for cellular research, namely fluorescence and slow speed (tied to lack of sensitivity) limit its utility- IR micro-spectroscopy is a powerful technique but its use in cellular analysis in particular has been limited due to the following 3 key limitations: a) Spatial resolution limited by diffraction to ~ 10 µm- b) Inability for in-vivo imaging due to strong IR absorption by water, and c) accurate measurement of absorption in biological samples is hard to achieve because of scattering artifacts tied to sample heterogeneity, where the wavelength dependence of light scattering causes significant baseline artifacts- This proposal eliminates all 3 of the above limitations of IR micro spectroscopy while ensuring that the instrument is able to do the measurement simultaneously over a wide area (128*128 pixels)- The proposal is based on a recently published and patent-pending photo-thermal IR spectroscopy (PT-IR) breakthrough- Anasys previously pioneered the field of AFM (Atomic force microscope) based nanoscale photothermal IR Spectroscopy where an AFM probe detects the photothermal signal induced by IR absorption, thus obtaining ~ 10 nm spatial resolution [5]- Over the last several years, this product has been commercialized successfully in multiple industries valuing nanoscale- However, the constraints imposed by the use of an AFM, have restricted its adoption in cellular research in particular and life sciences in general- However, his experience of pioneering nanoscale photothermal IR with an AFM probe has given Anasys almost 10 years (including 3 years of R&D prior to the commercialization) of product and technology development experience in optimizing a signal based on photothermal physics, which will prove very useful for this project-