Riboflavin based eutectogels for chiral recognition

In the vast panorama of fluorescent gels, one of the main drawbacks lies in the high effort on researching ad hoc fluorescent complexes, molecules, or nanomaterials capable of building supramolecular networks resulting in an optimal gelation process. In this field, the search for natural and fluorescent molecules to be exploited as fluorescent gelators is desirable due to their easier availability and low cost. Among the great variety of natural fluorescent dyes, riboflavin (Rbf) has recently acquired particular interest thanks to its multiple and interesting biological and chemical properties: from antioxidant activity to applications related to photocatalysis. However, research on riboflavin-based gels is rather scarce and only recently a very interesting contribution reported organogels based on riboflavin-melamine complexes. In our contribution, we investigate the gelation ability of riboflavin in non-conventional solvents, in particular deep eutectic solvents (DESs). The extension of this application to these solvents is of great interest with a view to the development of novel and functional soft materials. Currently our work has focused on screening the concentration dependent gelling ability of riboflavin based composites in DESs solvents, coupling this molecule with enantiomers of different amino acids, and studying the optical and chiro-optical properties. Our gel materials exhibit interesting fluorescence emission and the intrinsic chirality embed in their structure was exploited for addressing a comprehensive chiral recognition study.