A novel combination of DLS-optical microrheology and low frequency Raman spectroscopy to reveal underlying biopolymer self-assembly and gelation mechanisms.

The connectivity between gelation and increasing water confinement and structuring within nanopores of a thermally induced gel is demonstrated for the first time through low frequency Raman spectroscopy and optical microrheology measurements. Specifically, the work confirms that increased ordering of individual water molecules can be observed during the gelation of agarose upon cooling. More importantly, it illustrates the ability of the two techniques to provide new insights and a more direct link between intermolecular interactions/microstructure and evolving rheological response in gelling systems.