Highly efficient peroxidase-like activity of a metal–oxide-incorporated CeO₂–MIL(Fe) metal–organic framework and its application in the colorimetric detection of melamine and mercury ions via induced hydrogen and covalent bonds

Abstract

The illegal addition of melamine in dairy products and mercury (Hg2+) water contamination is a robust threat to human health. Hence, herein a highly sensitive colorimetric sensor for the visual...

Sensitive and Direct Analysis of Pseudomonas aeruginosa through Self-Primer-Assisted Chain Extension and CRISPR-Cas12a-Based Color Reaction

“…After magnetic isolation, the sediment comprising only MNPs is removed and the supernatant containing Ag + is exploited to oxidize TMB for color reaction. The solution that contained oxidized TMB (TMBox) had a blue color. ,, If P. aeruginosa is absent in the sensing system, Ag + -Apt–MNPs is removed after magnetic separation, and TMB cannot be oxidized by the supernatant.…”

“…The digestion of the aptamer by the Cas12a enzyme released Ag + to oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) for coloring. The solution that contained oxidized TMB (TMBox) had a blue color. , …”

“…The solution that contained oxidized TMB (TMBox) had a blue color. 39,40 2. EXPERIMENTAL SECTION 2.1.…”

Advances in the application of metal–organic framework nanozymes in colorimetric sensing of heavy metal ions

“…Colorimetric sensing was developed based on the turn-off–on mechanism and provided wide a linear range of 0–6 nM for Hg 2+ and a low LOD of 2 nM. 68 To further improve the sensitivity and accuracy of the assay, the porous MOFs were envisaged as solid media to uniformly anchor metal nanoparticles (MNPs) that also had enzyme-like catalytic activity to improve the catalytic performance of both. 69 For example, PtNPs@UiO-66-NH 2 composites were synthesized by Li and associates.…”

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

“…16,17 Recently, functional nanomaterials with enzyme-like activity, such as metal nanoparticles, oxide nanoparticles, carbon nanotubes, and metal-organic frameworks (MOFs), have been discovered and used as functional artificial enzymes. [18][19][20][21][22][23][24][25] Nevertheless, there are few metallohydrogels reported to be enzyme-mimetic materials. 26 Usually, hydrogels contain three-dimensional networks with porous structures and the water molecules sealed in them.…”