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.

Advances and Novel Perspectives on Colloids, Hydrogels, and Aerogels Based on Coordination Bonds with Biological Interest Ligands

“…To obtain a stable multifunctional MOG in the dark just in a single step through a spontaneous self-assembly process at room temperature is an objective that Neha Thakur et al [ 38 ] have been achieved by mixing Ag(I) with commercial inosine 5′monophsphate (IMP) ( Figure 9 ). This self-healable gel, formed by fibers of 8 nm in height measured by AFM and TEM, presents reversible gel–sol phase transitions in response to various external stimuli such as sulfate anions, acids, bases, and different salts.…”

“… Images of phase-selective separation of water from different water-oil mixtures by the Ag-IMP gel. Adapted from reference [ 38 ] with permission, copyright 2018 American Chemical Society. …”

Innovative Microstructural Transformation upon CO2 Supercritical Conditions on Metal-Nucleobase Aerogel and Its Use as Effective Filler for HPLC Biomolecules Separation

“…The fine-tuning of the synthetic conditions can even produce metal-organic gels (MOGs) in which these particles are interlinked into a meso/macroporous material [23,24]. In this regard, although increasingly understood, the gel's formation mechanisms remain far from being settled knowledge as many factors can affect both their formation and stability [14,[25][26][27][28][29][30][31]. Moreover, these new materials are linked to nanomaterials science since their obtaining implies mostly a bottom-up approach (to our knowledge, no precedents have been found for the preparation of metallogels via top-down approach) [32].…”

Schiff‐base‐functionalized polymeric hydrogel with high stretchability and multifunction

“…They are widely used in biomedicine, 5 sensor recognition, 6 and electronic devices 7 . According to previous studies, it is known that the self‐healing ability and multi‐stimulus responsiveness are the inevitable properties in the development of polymeric hydrogels 8‐10 …”