A Recent Advancement in Food Quality Assessment: Using MOF-Based Sensors: Challenges and Future Aspects.

Monitoring food safety is crucial and significantly impacts the ecosystem and human health. To adequately address food safety problems, a collaborative effort needed from government, industry, and consumers. Modern sensing technologies with outstanding performance are needed to meet the growing demands for quick and accurate food safety monitoring. Recently, emerging sensors for regulating food safety have been extensively explored. Along with the development in sensing technology, the metal-organic frameworks (MOF)-based sensors gained more attention due to their excellent sensing, catalytic, and adsorption properties. This review summarizes the current advancements and applications of MOFs-based sensors, including colorimetric, electrochemical, luminescent, surface-enhanced Raman scattering, and electrochemiluminescent sensors. and also focused on the applications of MOF-based sensors for the monitoring of toxins such as heavy metals, pesticide residues, mycotoxins, pathogens, and illegal food additives from food samples. Future trends, as well as current developments in MOF-based materials.

Influence of End-Capped Modifications in the Nonlinear Optical Amplitude of Nonfullerene-Based Chromophores with a D-π-A Architecture: A DFT/TDDFT Study.

Nonlinear optical (NLO) materials have several uses in many fields such as solid physics, biology, medicine, nuclear physics, and material research. Therefore, a series of nonfullerene-based derivatives (CC10D1-CC10D8) with a D-π-A configuration was planned for the NLO investigation using CC10R as the reference molecule with structural alternations at acceptor moieties. Natural bonding orbital (NBO), UV-vis spectra, frontier molecular orbitals (FMOs), global reactivity parameters (GRPs), transition density matrix (TDM), and density of states (DOS) were analyzed using the M06/6-311G(d,p) functional in chloroform solvent to understand the NLO responses of CC10R and CC10D1-CC10D8. The highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) band gaps of CC10D1-CC10D6 were illustrated to be lower than that of CC10R, with the larger bathochromic shift (726.408-782.674 nm) resulting in a significant NLO response. Along with the band gap, the FMO method also identified an efficient interfacial charge transfer from D to A moieties via a π-bridge, which was further supported by the DOS and TDM map. Moreover, NBO calculations demonstrated that extended hyperconjugation and strong internal molecular interactions were important in their stabilization. The dipole moment (µ), linear polarizability ⟨α⟩, hyperpolarizability (ßtotal), and second-order hyperpolarizability (γtotal.) were studied for CC10R and CC10D1-CC10D8. Among all of the derivatives, CC10D2 was proven to be the most appropriate candidate because of its suitable NLO behavior such as being well-supported by a reduced band gap (2.093 eV) and having a suitable maximum absorption wavelength (782.674 nm). Therefore, CC10D2 was reported to have a greater value of first hyperpolarizability (208 659.330 a.u.) compared with other derivatives and CC10R. For the second hyperpolarizability, a greater value was obtained for CC10R (5.855 × 107 a.u.), and its derivatives showed results comparable to that of the parent chromophore for γtotal. This theoretical framework reveals that structural customization with different acceptor units plays a significant role in obtaining attractive NLO materials for optoelectronic applications.

Synthesis of high performance Ni3C-Ni decorated thermally expanded reduced graphene oxide (TErGO/Ni3C-Ni) nanocomposite: A stable catalyst for reduction of Cr(VI) and organic dyes.

A high performance thermally expanded reduced graphene oxide (TErGO) nanocomposite decorated with Ni3C-Ni nanoparticles (TErGO/Ni3C-Ni) has been successfully synthesized by using a facile and eco-friendly approach. The morphology, textural features, surface composition and stability of TErGO/Ni3C-Ni nanocomposite are investigated by various physicochemical characterizations which revealed the uniform dispersion of crystalline metal nanoparticles inside TErGO matrix. The composite has been exhibited a large surface area and pore volume of 121 m2 g-1 and 0.791 cm3 g-1, respectively. The TErGO/Ni3C-Ni exhibited remarkable catalytic performance surpassing most metal-based catalysts with various kind of support matrices reported in recent literature. The reduction of Cr(Ⅵ) to Cr(Ⅲ) was achieved within 1 min with an excellent rate constant of 2.74 min-1 and phenomenally higher specific removal rate (SRR) of 0.29 mg Cr(VI) min-1. mg-1 of TErGO/Ni3C-Ni. While it also proved an excellent reducing catalyst for organic dyes via NaBH4 with full reduction achieved within 30 s. Moreover, as prepared nanocatalyst possesses excellent stability and recyclability with easy magnetic separation.

Preparation of polymer/calcium phosphate porous composite as bone tissue scaffolds.

Composite scaffolds, especially polymer/calcium phosphate composite scaffolds with porous structures are promising materials for bone tissue engineering. Depositing minerals on the surface of polymer scaffolds is a general method however, attachment between inorganic minerals and organic polymeric is a big challenge, because of the absence of strong interactions between the interfaces. In this work, polymer/calcium phosphate composite scaffolds with good attachment were fabricated through introduction of calcium and alternate mineralization. Calcium methacrylate was polymerized into the polymer scaffold and calcium acted as "ion glue" endowing the polymer/calcium phosphate composite good interfacial interaction. After alternate mineralization, the surface of polymer scaffold with calcium was coated with plate-like minerals which attached to polymer well and composite scaffold preserved the porous morphology. The results demonstrated that the concept of "ion glue" provided an option for the improvement of attachment between inorganic minerals and organic polymer. The results also indicated that the good attachment of minerals with polymer scaffolds enhanced the mechanical properties and improved the cell attachment of the polymer scaffolds.

Regional selective construction of nano-Au on Fe3O4@SiO2@PEI nanoparticles by photoreduction.

A magnetically separatable catalyst Fe3O4@SiO2@PEI@Au (gold) nanoparticle was successfully constructed by a novel regional selective photoreduction method. Based on the photolysis mechanism of a type II photoinitiator, through controlling the distribution of polyethylene imine (PEI), Au nanoparticles about 10 nm, which are only on the surface of the Fe3O4@SiO2@PEI nanoparticle, could be photoreduced due to the PEI acting as a coordinating agent, capping agent, and photoreducing agent simultaneously. The small size Au nanoparticles endow the catalyst with a high catalytic performance toward the reduction of 4-nitroaniline to 4-aminophenol by NaBH4. In addition, magnetic Fe3O4@SiO2@PEI@Au nanoparticles could easily be recovered and could be reused at least six times still keeping catalytic efficiency higher than 95%, which contributes to their high stability and magnetization. Furthermore, compared to another reported approach, this method showed great regional selectivity of reducing metal nanoparticles by controlling the distribution of the PEI. Taking advantage of the regional selectivity of the photoreducing method could also be used to fabricate other metal nanoparticles as catalysts for various reactions.

Characterization and application of chondroitin sulfate/polyvinyl alcohol nanofibres prepared by electrospinning.

Composite nanofibres were prepared by electrospinning from a solution of chondroitin sulfate and polyvinyl alcohol. The chondroitin sulfate/polyvinyl alcohol (CS/PVA) mass ratios of 7/3 has a uniform and smooth morphology, and the average diameter of the nanofibres was 136nm. Combretastatin A-4 phosphate was loaded on the nanofibres and used as a model for testing drug release from the nanofibres crosslinked with glutaric dialdehyde. The morphology and structure of the nanofibres was determined using scanning electron microscopy. In order to assess their possible application to tissue engineering scaffolds, the toxicity and cytocompatibility of the nanofibres were tested by methylthiazolydiphenyl-tetrazolium bromide assay.