Multifunctional Inosine Monophosphate Coordinated Metal-Organic Hydrogel: Multistimuli Responsiveness, Self-Healing Properties, and Separation of Water from Organic Solvents

Abstract

Outfitted with numerous coordination and hydrogen bonding sites, nucleotides represent a class of naturally occurring ligands for coordination with metals leading to both hard and soft materials for a wide range of applications. Reported herein, a new multistimuli-responsive metal-organic hydrogel through the spontaneous self-associative complexation of inosine 5′-monophosphate (IMP) with Ag(I) ions in aqueous medium. The strong and optically transparent hydrogels were formed without the aid of any external influences such as heating/cooling cycles or ultrasonication and comprise of an interconnected matrix of nanofilaments constructed from helically stacked, chiral arrays of Ag-IMP dimers. The metallogel exhibits diverse properties including self-healing, stimuli-responsiveness, transparency, and injectibility. The direct gelation specificity to Ag (I) ions is highly phase selective only to water, and the ability of the freeze-dried xerogel to gel water is exploited for the separation of water from various organic solvents. Further, the Ag-IMP hydrogel exhibits efficient antibacterial activity against both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) bacteria. Ag nanoparticles could be generated in situ without disrupting the hydrogel network through photoreduction by light. The robustness and multidimensional applicability combined with ease of synthesis make this coordination driven hydrogel a prospective material for environmental and biomedical applications. © 2018 American Chemical Society.