Peroxidase activity of a Cu-Fe bimetallic hydrogel and applications for colorimetric detection of ascorbic acid

A Cu-Fe bimetallic hydrogel (2-QF-CuFe-G) was constructed through a simple method. The 2-QF-CuFe-G metallohydrogel possesses excellent peroxidase-like activity to catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2. The catalytic mechanism was confirmed by the addition of •OH radical scavenger isopropyl alcohol (IPA), tert-butyl alcohol (TBA) and ˙OH trapping agent terephthalic acid (TA). Remarkably, the resultant blue ox-TMB system can be used to selectively and sensitively detect ascorbic acid (AA) with an LOD of 0.93 μM in the range of 4-36 μM through the colorimetric method. Moreover, the assay based on the 2-QF-CuFe-G metallohydrogel can be successfully applied to detect AA in fresh fruits.

Amino acid derivative-based Ln-metallohydrogels with multi-stimuli responsiveness and applications

Metallohydrogels and lanthanide (Ln) fluorescent materials have gained much attention recently. In this study, we designed and synthesized a facile gelator of a phenylalanine-based derivative containing an indazole group (namely IZF). It was found that IZF can self-assemble to form hydrogel at pH ≤ 7. Meanwhile, IZF and Tb³⁺/Eu³⁺ can co-assemble to generate IZF-Tb and IZF-Eu metallohydrogels with green and red fluorescence, respectively, at pH 8-11, with excellent multi-stimuli responsiveness. The bimetallic hydrogels of IZF-Tb/Eu exhibit different colors under UV light by adjusting the ratio of Tb³⁺ and Eu³⁺. Moreover, white light emission was achieved with IZF-Tb/Eu bimetallic gels through doping carbon dots (CDs) by tailoring the stoichiometric ratio of Ln-complex and CDs. Remarkably, IZF-Tb and IZF-Eu could be used as fluorescent inks with excellent stability. This study indicates that the amino acid derivative-based Ln-metallohydrogels are excellent candidates for constructing information storage and multiple anti-counterfeiting materials.

Steroidal supramolecular metallogels

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

An “off–on” fluorescent naphthalimide-based sensor for anions: its application in visual F− and AcO− discrimination in a self-assembled gel state

Herein, we report a novel fluorescent organogelator that could discriminate F⁻ from AcO⁻ in both solution and gel systems.

Unique Design of Porous Organic Framework Showing Efficiency toward Removal of Toxicants

This report deligates about the creation of porous polymeric organic framework (POF) from dialkynes and poly(alkyne) with their discovery as an efficient set of purifier. POF showed efficient physisorption for dyes-fluorescein and rhodamine B. The material POF selectively released rhodamine B and not fluorescein. The material was recyclable over number of cycles during the adsorption-release cycle. Moreover, the thiol-functionalized POF expectedly showed chemisorption for mercury. Therefore, the prime attractive cause for such a material is its ability to recycle as well as its thiol functionalization toward the removal of heavy metal such as mercury.

A versatile platform for lanthanide(iii)-containing organogelators: fabrication of the Er(iii)-incorporated polymer nanocomposite from an organogel template

An Er(iii)-containing polymer nanocomposite that showed an enhanced NIR emission was prepared from an organogel template via post-gelation polymerisation.

Polymers made of bile acids: from soft to hard biomaterials

Bile acids are gaining increasing importance as building blocks in the development of novel polymeric materials. This is evidenced by the growing number of publications advocating the advantages of their incorporation in the design and construction of materials. Composed of a rigid steroid backbone, functional groups with potential towards diverse reactions, and a biocompatible framework, there are various ways in which these molecules can be utilized to afford biomaterials via distinct architectures. Soft materials utilize the intrinsic capacity of bile acids to self-assemble and have seen a range of applications, most notably in the field of drug delivery. On the other hand, there is also the possibility of including bile acids in the polymer backbone, which has been used in the preparation of elastomers. This review discusses a selection of materials that can be prepared using bile acids and the advantages afforded by these molecules. Focus will be on the development of soft and hard materials, where soft materials are described as being held by weak intermolecular interactions, whereas hard materials are mechanically stronger with bile acids covalently incorporated in the polymer network.

Two-dimensional coordination polymers and metal–organic gels of symmetrical and unsymmetrical dipyridyl β-diketones: luminescence, dye absorption and mechanical properties

The ligands containing chelating as well as exodentate functional groups were shown to form functional coordination polymers and heterometallic gels.

Formation of molecular hydrogels from a bile acid derivative and selected carboxylic acids

A cholic acid dimer forms hydrogels with selected carboxylic acids via protonation and hydrogen bonding.

Metallosupramolecular Materials for Energy Applications: Light Harvesting

Excitation energy transfer, a key process in natural light harvesting systems, has been extensively investigated with the help of synthetic molecular and supramolecular systems. The knowledge gathered from these studies has contributed to the development of novel energy harvesting materials that could find applications in nano-electronics and photonics, of which metallosupramolecular assemblies are one such class. In this chapter, the exciting developments in the use of metallosupramolecular materials in energy applications such as light harvesting are described. Emphasis is given to the state-of-the-art summary in the design and properties of metal–organic frameworks, self-assembled coordination polymers and metallogels, which all have prospects for light harvesting applications.