Noninvasive chemical analysis of biological systems based on advanced coherent Raman microspectroscopy

• Applicant: Dr. Andreas Volkmer
• Subject Area: Biological and Biomimetic Chemistry
• Term: from 1999 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5209606

The main objective of the proposed project is the detailed study of biological processes and their functions on a single molecule level. Only real-time monitoring allows direct observation and separation of static and dynamical heterogenity of molecular properties, which are normally hidden in ensemble averages. Experimental trajectories of a single molecule property will be obtained by applying two complementary spectroscopic methods. First, characteristic fluorescence parameters, such as fluorescence intensity, lifetime, anisotropy and spectrum, obtained upon excitation of the intrinsic fluorophore (flavin adenine dinucleotide) in flavoproteins, will be monitored in real time. The second part of the proposed project is to explore a new spectral observation window to the vibrational frequency for single-molecule methodology by employing Coherent Anti-Stokes Raman Scattering (CARS) microscopy. The objective is to monitor the amide bands, which are intrinsic vibrationals signature for protein secondary structures. The stochastic trajectory analysis of spectroscopic parameters followed by both methods, fluorescence and CARS, will allow the detection and quantification of molecular structure changes on a single molecule basis and enables therefore extraction of fundamental conformational protein dynamics information.

• DFG Programme: Independent Junior Research Groups