Coordination Polymer Gels (CPGs) constitute a subset of solid-like metal ion and bridging organic ligand structures (similar to metal-organic frameworks) that form multi-dimensional networks through a trapped solvent as a result of non-covalent interactions. While physical properties of these gels are similar to conventional high molecular weight organic polymer gels, coordination polymer gel systems are often fully reversible and can be assembled and disassembled in the presence of additional energy (heat, sonication, shaking) to give a solution of solvated gelators. Compared to gels resulting from purely organic self-assembled low molecular weight gelators, metal ions incorporated into the fibrilar networks spanning the bulk solvent can impart CPGs with added functionalities. The solid/liquid nature of the gels allows for species to migrate through the gel system and interact with metals, ligands, and the solvent. Chemosensing, catalysis, fluorescence, and drug-delivery applications are some of the many potential uses for these dynamic systems, taking advantage of the metal ion's coordination, the organic polydentate ligand's orientation and functionality, or a combination of these properties. By fine tuning these systems through metal ion and ligand selection and by directing self-assembly with external stimuli the rational synthesis of practical systems can be envisaged.

Functionalized magnetic nanoparticles, composed of both inorganic and organic components, have recently been examined as promising platforms for detection and separation applications. This unique class of nanomaterials can retain not only beneficial features of both the inorganic and organic components, but can also provide the ability to systematically tune the properties of the hybrid materials through the combination of appropriate functional components. This tutorial review focuses on the recent development of functionalized magnetic nanoparticles for use in biological and environmental applications, in which these chromogenic and fluorogenic chemosensors can selectively detect and separate specific toxic metal ions.

Mitochondria are organelles that are readily susceptible to temperature elevation. We selectively delivered a coumarin-based fluorescent iron oxide nanoparticle, Mito-CIO, to the mitochondria. Upon 740 nm laser irradiation, the intracellular temperature of HeLa cells was elevated by 2.1 °C within 5 min when using Mito-CIO, and the treatment resulted in better hyperthermia and a more elevated cytotoxicity than HeLa cells treated with coumarin iron oxide (CIO), which was missing the mitochondrial targeting unit. We further confirmed these results in a tumor xenograft mouse model. To our knowledge, this is the first report of a near-infrared laser irradiation-induced hyperthermic particle targeted to mitochondria, enhancing the cytotoxicity in cancer cells. Our present work therefore may open a new direction in the development of photothermal therapeutics.

A tetrazole-based ligand forms a supramolecular metallogel in the presence of Ag + in aqueous solution at basic condition. The silver-induced metallogel has been characterized by SEM, TEM, XRD and rheometry. The metallogel exhibits a fiber structure. Upon standing, silver nanoparticles grow in the gel. TEM confirmed that the particles are exclusively formed in the gel fibers. The size of the silver nanoparticles formed on the gel fibers is dependent to the concentration of silver during gel formation. The silver nanoparticles show a face-centered cubic crystalline structure. The silver nanoparticles can effectively catalyze reduction of 4-nitrophenol by sodium borohydride in aqueous solution. The formation of Ag + -induced metallogels does not strongly depend on anions. According to DFT calculations, two silver cations are coordinated to nitrogen at the tetrazole moiety. The other silver cation is coordinated to the nitrogen of the pyridine and coordinated to the oxygen of the amide moiety. Furthermore, the rheological properties of the Ag + -tetrazole-based metallogel were strongly dependent on the concentration of AgClO 4 .

Finely controlled circularly polarized luminescence (CPL) supramolecular polymerization based on a tetraphenylethene core with four l‐ or d‐alanine branch side chains (l‐1 and d‐1) in the solution state is presented, resulting from the tuning of mechanical stimulus. Weak, green emissions of l‐1 and d‐1 in tetrahydrofuran (THF) were converted into strong blue emissions by tuning the mechanical stimulus. The strong blue emissions were caused by an aggregation‐induced emission (AIE) effect during the formation of a supramolecular polymer. Lag time in the supramolecular polymerization was drastically reduced by the mechanical stimulus, which was indicative of the acceleration of the supramolecular polymerization. A significant enhancement of circular dichroism (CD) and CPL signals of l‐1 and d‐1 was observed by tuning the rotational speed of the mechanical stimulus, implying that the chiral supramolecular polymerization was accelerated by the mechanical stimulus.