A Stimuli-Responsive Metallohydrogel Exhibiting Cyclohexane-Like Hydrophobicity

An Encyclopedic Compendium on Chemosensing Supramolecular Metal-Organic Gels

Chemosensing, an interdisciplinary scientific domain, plays a pivotal role ranging from environmental monitoring to healthcare diagnostics and (inter)national security. Metal-organic gels (MOGs) are recognized for their stability, selectivity, and responsiveness, making them valuable for chemosensing applications. Researchers have explored the development of MOGs based on different metal ions and ligands, allowing for tailored properties and sensitivities, and have even demonstrated their applications as portable sensors such as paper-based test strips for practical use. Herein, several studies related to MOGs development and their applications in the chemosensing field via UV-visible or luminance along with electrochemical approach are presented. These papers explored MOGs as versatile materials with their use in sensing bio or environmental analytes. This review provides a foundational understanding of key concepts, methodologies, and recent advancements in this field, fostering the scientific community.

Energy transfer in FRET pairs in a supramolecular hydrogel template

Fluorescence resonance energy transfer (FRET) in pairs of chromophores has mostly been achieved using covalently bound chromophores. In this study, we have demonstrated energy transfer in FRET pairs by taking advantage of the self-assembly of the chromophores on metal cholate hydrogel fibers.

Steroidal supramolecular metallogels

Steroidal supramolecular metallogels combine the properties of steroids with metal ions resulting in multi-responsive systems possessing many potential applications.

Supramolecular tripodal Au(i) assemblies in water. Interactions with a pyrene fluorescent probe

The synthesis of three gold(i) tripodal complexes derived from tripropargylamine and containing the water soluble phosphines PTA (1,3,5-triaza-7-phosphaadamantane), DAPTA (3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane) and TPPTS (triphenylphosfine-3,3′,3′′-trisulfonic acid trisodium salt) is described here.

Down-regulating Proteolysis to Enhance Anticancer Activity of Peptide Nanofibers

Nanofibers of short peptides are emerging as a promising type of agents for inhibiting cancer cells. But the proteolysis of peptides decreases the anticancer efficacy of the peptide nanofibers. Here we show that decreasing the activity of proteasomes enhance the activity of peptide nanofibers for inhibiting cancer cells. Based on the structure of galactin-3, we designed a heptapeptide, which self-assembles to form nanofibers. The nanofibers of the heptapeptide exhibit moderate cytotoxicity to three representative cancer cell lines (HeLa, MCF-7, and HepG2), largely due to the proteolysis of the peptides. Using a clinically approved proteasome inhibitor, bortezomib, to treat the cancer cells significantly decreases the proteolysis of the peptides and enhances the activity of the peptide nanofibers for inhibiting the cancer cells. This work illustrates a promising approach for enhancing the anticancer efficacy of peptide nanofibers by modulating intracellular protein degradation machinery, as well as provides insights for understanding the cytotoxicity of aberrant protein or peptide aggregates in complicated cellular environment.

Rheoreversible Metallogels Derived from Coordination Polymers

A series of mixed-ligand-based Cd^II /Co^II coordination polymers (CPs) that were derived from two bis(pyridyl)-bis(amide) ligands, 4,4'-oxybis(N-(pyridin-3-yl)benzamide) (LP) and 4,4'-oxybis(N-(pyridin-4-yl)benzamide) (LP1), and a variety of dicarboxylates isophthalates, terephthalates, 1,2-carboxytranscinamates, and 1,3- and 1,4-phenylene dicarboxylates were synthesized based on a rationale that they would occlude solvate guests inside their crystal lattice, thereby rendering these CPs suitable as metallogelators. The CPs were characterized by using single-crystal X-ray diffraction, elemental analysis, powder X-ray diffraction (PXRD), FTIR spectroscopy, and thermogravimetric analysis (TGA). Structural analyses revealed that the majority of the CPs were lattice-occluded molecular solids, which provided us with an opportunity to study their gelation behavior. We observed that, out of eight CPs that were tested, seven were able to produce metallogels. A thorough study of the rheological behavior of the metallogels was performed and CPG1, CPG2, CPG4, and CPG5 were found to exhibit rheoreversible behavior, which was further confirmed by rheological experiments. Interestingly, ligand LP was found to form an aqueous gel, which was exploited to produce silver nanoparticles.

Metallogels of indium(iii) with bile salts: soft materials for nanostructured In2S3 synthesis

Metallo-hydrogels were formed from sodium cholate and deoxycholate in the presence of indium(iii). This soft hydrogel was used for nanostructured In₂S₃ synthesis.