Prof. Rohit Bhargava and his interdisciplinary team at the University of Illinois are supported by the Chemical Measurement and Imaging Program in the Division of Chemistry to develope comprehensive and innovative methods for extracting knowledge from chemical imaging (CI) by (i) improving CI data both in time (by compressed sensing) and in signal-to-noise ratio (by noise reduction); (ii) developing novel data analysis algorithms that synergistically process spatial and spectral information; and (iii) extracting information about complex patterns and natural interactions that cannot be discerned currently by examination of structure alone. The approaches are being optimized on existing FT-IR and Raman imaging systems, and applied to study structure evolution in complex human tissues during malignant transformation.
Imaging has traditionally focused on visualizing structure. This project broadly focuses on effectively visualizing the chemistry of materials by enhancing theory and computation in the emerging area of CI. The data enhancement approaches developed in this project will be broadly applicable to multiple analytical techniques and to all fields of application. Hence, the project is expected to widely accelerate scientific discovery and technological progress in, for example, materials science (e.g. in polymer composites), biological sciences (e.g. in lethal cancer transformation), and forensics (e.g. detecting prints). The developed tools and educational activities will enhance infrastructure and help build the national and international CI community. Tools and dissemination proposed here will help build partnerships between CI, computational, and biomedical scientists - allowing for rapid dissemination of results to industry and other practitioners. The project will train a diverse group of undergraduate and graduate students in cross-disciplinary science, including mathematics, physics, chemistry, engineering, biology, and computing. Underrepresented groups will be involved and nurtured into this emerging area by sustained mentoring. Finally, the developed techniques are expected to be translated to commercial instruments, contributing to widespread use.
The project focused on developing novel theoretical tools and computational methods for vibrational spectroscopic imaging. Both infrared and Raman spectroscopy and imaging were the subject of the project. Focusing on novel understating of the signal origin and image formation processes, we were able to develop new capabilities. We developed a comprehensive theoretical understanding, first, of image formation in the mid-infrared (IR). This advance allows us and other scientists to study how we can understand molecular details of materials that will help better diagnose disease, design future materials and provide new capabilities in forensics or plant biology. This advance in fundamental theory allows us to better understand data and better design instruments. For example, we showed that 100 times smaller pixels than previously thought could be obtained using IR imaging. This advance, termed high definition (HD) imaging, has led to the incorporation into commercial products, better imaging to diagnose prostate and breast cancer as well as better understand theory. Using new numerical processing techniques, we were able to show that the imaging process itself can be speeded up by 10-100 times. We also developed a theoretical understanding for Raman spectroscopic measurements and imaging for sensitive chemical measurements using surface enhanced spectroscopy. We were able to provide a theoretical framework for accurate extraction of data. This will enable chemical measurements inside the human body, for example, leading to better diagnostic tests. The developments in this project were made publicly available via more than 25 reports in scientific journals, 50 presentations at various venues, demonstrations and transfer of information to industry. School (K-12) students were involved in learning using materials from this project. Almost a dozen students (postgraduate to high schoolers) were directly trained using the materials in this project. A website reports on the progress in the grant and software is available for use by scientists.
