Immobilizing nanozymes on 3D-printed metal substrates for enhanced peroxidase-like activity and trace-level glucose detection.

The prevalence of 3D-printed portable biomedical sensing devices, which are fashioned mainly from plastic and polymer materials, introduces a pressing concern due to their limited reusability and consequential generation of substantial disposable waste. Considering this, herein, we pioneered a ground-breaking advancement, i.e., a 3D-printed metal substrate-based enzyme. Our inventive methodology involved the synthesis of a thermally degraded Fe-based metal-organic framework, DEG 500, followed by its deposition on a 3D-printed metal substrate composed of Ti-Al-V alloy. This novel composite exhibited remarkable peroxidase-like activity in a range of different temperatures and pH, coupled with the ability to detect glucose in real-world samples such as blood and fruit juices. The exceptional enzymatic behaviour was attributed to the diverse iron (Fe) oxidation states and the presence of oxygen vacancies, as evidenced through advanced characterization techniques. Fundamentally, we rigorously explored the mechanistic pathway through controlled studies and theoretical calculations, culminating in a transformative stride toward more sustainable and effective biomedical sensing practices.

Direction of theoretical and experimental investigation into the mechanism of n-HA/Si-PA-SC@Ag as a bio-based heterogeneous catalyst in the reduction reactions.

In the present study, a natural-based heterogeneous catalyst is synthesized. For this purpose, nano-hydroxyapatite (n-HA) is prepared, silica-modified and functionalized with phthalimide. Finally, Ag2+ was immobilized onto n-HA/Si-PA-SC and reduced to Ag nanoparticles by Bellis perennis flowers extract. n-HA/Si-PA-SC@Ag characterized by TGA, FTIR, SEM/EDX, XRD, TEM, BET and ICP-AES techniques. Moreover, metal-ligand interactions in n-HA/Si-PA-SC@Ag complex models were assessed to make a quantitative representation for the immobilization behavior of Ag NPs on the surface of n-HA/Si-PA-SC through quantum chemistry computations. Furthermore, the performance of n-HA/Si-PA-SC@Ag was studied in the nitroarene, methylene blue and congo red reductions. Finally, the recyclability study as well as Ag-leaching verified that, n-HA/Si-PA-SC@Ag was stable and reused-up to four times without losing its activity.

Retraction Note to: Computational studies on the regioselectivity of metal-catalyzed synthesis of 1,2,3 triazoles via click reaction: a review.

The editor has retracted this article (1) because it contains sections that substantially overlap with a number of previously published sources without appropriate citation and acknowledgment (2, 3, 4, 5).

Correction: Computational investigations of click-derived 1,2,3-triazoles as keystone ligands for complexation with transition metals: a review.

[This corrects the article DOI: 10.1039/C8RA00283E.].

Computational investigations of click-derived 1,2,3-triazoles as keystone ligands for complexation with transition metals: a review.

In recent years, metal complexes of organo 1,2,3-triazole click-derived ligands have attracted significant attention as catalysts in many chemical transformations and also as biological and pharmaceutical active agents. Regarding the important applications of these metal-organo 1,2,3-triazole-based complexes, in this review, we focused on the recently reported investigations of the structural, electronic, and spectroscopic aspects of the complexation process in transition metal complexes of 1,2,3-triazole-based click ligands. In line with this, the coordination properties of these triazole-based click ligands with transition metals were studied via several quantum chemistry calculations. Moreover, considering the complexation process, we have presented comparative discussions between the computational results and the available experimental data.

Computational studies on the regioselectivity of metal-catalyzed synthesis of 1,2,3 triazoles via click reaction: a review.

Recently, the experimental and computational chemists have been attracted widely to the click synthesis of 1,2,3 triazoles and their derivatives, mainly due to the fact that they are interesting from structural and mechanistic points of view. Moreover, catalyzed click have been well established as a successful strategy showing high regioselectivity and high yield for the synthesis of 1,2,3-triazoles. In this review, we try to highlight the recently reported computational assessments on the origins and predection of regioselectivity in the catalyzed click synthesis of triazoles from the mechanistic and thermodynamical points of view. In this light, density functional theory (DFT) calculations on the free energy profiles of azide-alkyne cycloaddition reactions have been underscored. The stereoelectronic features for the role of copper, ruthenium, and iridium as catalyst on regioselectivity of click reactions have also be discussed. Graphical Abstract Computational origins for the regioselective behavior of 1,2,3 triazoles click synthesis.

Regioselectivity in Sonogashira synthesis of 6-(4-nitrobenzyl)-2-phenylthiazolo[3,2-b]1,2,4-triazole: a quantum chemistry study.

In the present research, the experimentally observed regioselectivity in Sonogashira synthesis of 6-(4-nitrobenzyl)-2-phenylthiazolo[3,2-b]1,2,4triazole has been modeled by means of density functional theory (DFT) employed to investigate the structural and thermochemical aspects of this synthesis in the gas and solution phases. Comparison of our calculated structural parameters of the title compound with the available X-ray crystallographical data demonstrate a reliable agreement. Then, the effect of two different solvents, DMF and ethanol, are examined via polarized continuum model calculations, showing a significant decrease in the computed values of the reaction enthalpy and free energy changes compared with the gas phase results. We have also considered two tautomeric structures of the intermediate species that it seems the mode of its intermolecular cyclization has an important role in regioselectivity of the final products. Moreover, all obtained results in the gas and solution phases also confirm that the synthesis of the title compound is thermodynamically more favorable than the other regioisomeric product. We also discuss the thermodynamical feasibility of this reaction at higher temperatures. Finally, we concentrate on the survey of substituent effect by choosing electron-withdrawing and electron-donating groups on the aryl iodide. Our calculated thermochemical data in the gas and solution phases indicate that the use of electron-withdrawing moieties is more favorable thermodynamically than electron-donating ones which has been previously concluded via the experimental elucidations.