Operando UV Resonance Raman study of DNA-ionic liquids gels

Double-stranded DNA dissolved in aqueous solutions of imidazolium-based Ionic Liquids (ILs) exhibits a characteristic gel transition, leading to the formation of DNA ionogels. In this study, we utilize state-of-the-art operando UV Resonance Raman (UVRR) spectroscopy, along with UV and Circular Dichroism (CD) absorption experiments, to monitor the self-assembly of a class of DNA ionogels derived from low-concentration aqueous solutions of DNA in imidazolium-based ILs. Our experimental approach offers insights at the molecular level into the structural organization and interactions that stabilize the gel network. Furthermore, operando UVRR spectroscopy allows efficient monitoring of the different stages of the thermal pathway leading to the self-assembly of DNA/ILs solutions into ionogels. A key achievement of our study is demonstrating that the sol–gel transition in DNA ionogels in the presence of imidazolium-based ILs can be modulated by the length of the alkyl chain of the imidazolium cation to achieve desired premelting, melting, and gelation temperatures.