Thermal Characterization of Biopolymers

01.01.2016, 00:00

Newsletter 9

The structure of biopolymers is known to change with temperature, affecting for example the activity of enzymes and the folding of proteins. We have now shown that such structural changes can be monitored using highly sensitive “whispering gallery mode” (WGM) optical biosensors. To achieve this goal, we have devised a technique to temperature-stabilize the WGM sensor system, by adding glycerol to a WGM glass microsphere placed in an aqueous sensing environment. The temperature stabilized WGM sensor was utilized to track structural changes in biopolymers, by monitoring frequency shifts associated with optical polarizability change. Using this sensing method, structural chan-ges in albumin protein (see Figure) could be resolved for only one degree in temperature variation. Such highly sensitive detection of structural change can have many important applications: in single molecule studies, for thermodynamic investigations of biological systems, and for monitoring temperature-dependent reaction kinetics.

Contact: frank.vollmer(at)mpl.mpg(dot)defrank.vollmer(at)mpl.mpg(dot)de
Group: Biophotonics and Biosensing (MPRG)
Reference: E. Kim et al., Applied Physics Letters 106, 161101 (2015).