Label-free Vibrational Imaging Techniques for Applications in Biological and Chemical Analysis

In this project the aim is to develop vibrational 'chemically selective' imaging techniques for bio-chemical applications. Techniques based on coherent Raman scattering (CRS), which are vibrational finger-printing techniques, and much more powerful than conventional spontaneous Raman spectroscopy will be used. In CRS the signals are much stronger to allow in situ real-time imaging yet can be as informative and chemically selective as Raman spectroscopy. The signals can be further enhanced using the phenomena of electronic resonance to further enable highly sensitive detection. This is applicable to monitoring compounds such as tetrapyrroles, which have accessible resonances in the visible and near infrared wavelength range. Tetrapyrroles, which include molecules such as protoporphyrin IX, heme, cytochrome C, biliverdin, bilirubin etc., are a highly important class of molecules involved in many life processes. Malfunctions in the biochemical pathways involving them lead to diseases but their beneficial effect is used in cancer treatment as well. Thus in this project chemically selective micro-/nano-scopic CRS imaging techniques will be developed to monitor phenomena related to tetrapyrrole, and in particular protophyrin IX, pathways in mammalian and plant cells. This will provide a step change in current understanding of the relevant biochemical pathways and accelerate translation of treatment strategies