Nanozyme Rich in Oxygen Vacancies Derived from Mn-Based Metal–Organic Gel for the Determination of Alkaline Phosphatase

Abstract

Vacancy engineering as an effective strategy has been widely employed to regulate the enzyme−mimic activity of nanomaterials by adjusting the surface, electronic structure, and creating more active sites. Herein, we purposed a facile and simple method to acquire transition metal manganese oxide rich in oxygen vacancies (OVs-Mn 2 O 3 -400) by pyrolyzing the precursor of the Mn(II)-based metal−organic gel directly. The as-prepared OVs-Mn 2 O 3 -400 exhibited superior oxidase-like activity as oxygen vacancies participated in the generation of O 2•− . Besides, steady state kinetic constant (K m ) and catalytic kinetic constant (E a ) suggested that OVs-Mn 2 O 3 -400 had a stronger affinity toward 3,3′,5,5′-tetramethylbenzidine and possessed prominent catalytic performance. By taking 2-phospho-Lascorbic acid as the substrate, which can be converted into reducing substance ascorbic acid in the presence of alkaline phosphatase (ALP), OVs-Mn 2 O 3 -400 can be applied as an efficient nanozyme for ALP colorimetric analysis without the help of destructive H 2 O 2 . The colorimetric sensor established by OVs-Mn 2 O 3 -400 for ALP detection showed a good linearity from 0.1 to 12 U/L and a lower limit of detection of 0.054 U/L. Our work paves the way for designing enhanced enzyme-like activity nanozymes, which is of significance in biosensing.

Cu/Zr Metal–Organic Frameworks with High Peroxidase-Like Activity for Sensitive Electrochemical and Colorimetric Dual-Mode Detection of Hydrogen Peroxide Released from Living Cells

“…Different free radical scavengers were used to explore other active oxygen species in the TMB+H 2 O 2 +Cu/Zr-MOF system. Various scavengers such as thiourea, p-benzoquinone (PBQ), and histidine were separately added to capture ·OH, O 2 – , and 1 O 2 in Figure C. , The addition of thiourea significantly reduced the catalytic activity of Cu/Zr-MOF, indicating the presence of ·OH in the TMB+H 2 O 2 +Cu/Zr-MOF system. The catalytic activity decreased by about 22.3% after adding P-benzoquinone (PBQ), indicating the presence of extremely few O 2 – .…”

An Encyclopedic Compendium on Chemosensing Supramolecular Metal‐Organic Gels

“…Recently, in another innovative study by the same group, they employed a similar method to produce manganese oxide enriched with oxygen vacancies (OVs-Mn 2 O 3 -400) through the direct pyrolysis of a Mn(II)-based metal-organic gel precursor. [132] The researchers successfully induced oxygen vacancies on the material's surface, whose illustration is shown in Figure 3F. This approach proved effective in enhancing the oxidase-like activity of OVs-Mn 2 O 3 -400, showcasing its potential as a catalyst.…”

A comprehensive exploration of the latest innovations for advancements in enhancing selectivity of nanozymes for theranostic nanoplatforms

“…101 In particular, OV-Mn 3 O 4 outperforms Mn 3 O 4 Nanoflowers (NFs) in the detection of l -cysteine, offering a significantly lower detection limit (1.31 μM vs. 5.69 μM). 102 Additionally, Song et al synthesized OVs-rich manganese oxide (OVs-Mn 2 O 3 -400) by pyrolyzing an Mn( ii )-based metal–organic gel precursor. OVs-Mn 2 O 3 -400 exhibited robust OXD-like activity, leveraging oxygen vacancies to produce O 2 ˙ − (Fig.…”