Alkaline-Stable Peroxidase Mimics Based on Biological Metal–Organic Frameworks for Recyclable Scavenging of Hydrogen Peroxide and Detecting Glucose in Apple Fruits

Abstract

Enzyme mimics constitute a promising class of biocatalysts with potential applications in bioanalysis, biomedicine, etc. due to their high catalytic activity and substrate specificity, but they often suffer from low operational stability and difficulties in recyclable utilization. Herein, we adopted an acid–base treatment to create an efficient enzyme mimic material by taking advantage of biological metal–organic frameworks (BioMOFs) constructed of the Cu2+ ion and a plant growth regulator. The prepared deprotonated dinuclear BioMOF exhibits excellent stability in alkaline environments and high peroxidase-mimicking activity. The enzyme mimic shows a quick reaction capability of H2O2 scavenging in the linear range of 0–0.2 μM mL–1 under neutral conditions and a sustained scavenging ability under strong alkaline conditions. Unlike general Cu-based peroxidase mimics, the BioMOF directly hydrolyzes H2O2 into O2 2– instead of the •OH radical and degrades to its synthetic precursor. The cyclic utilization, therefore, can be achieved by the interconversion between the BioMOF and its degraded product. Additionally, a hybrid nanomaterial (BioMOF-NPs) was developed by immobilizing the BioMOF and chitosan nanoparticles. The fabricated BioMOF-NPs display improved reliability and repeatability of the H2O2-scavenging effect due to the large specific surface area. Based on the BioMOF-NPs, selective glucose determination is achieved in the linear range of 5–25 μM with a detection limit of 1.93 μM. The method is successfully utilized for the recyclable detection of glucose in apple fruits. This study offers a new strategy for designing structure-interconvertible BioMOFs for applications of biological analysis.

Recognition, detection and host–guest chemistry of hydrogen peroxide in a fluorescent metal–organic framework with chiral helical channels

“…To demonstrate the encapsulation of H 2 O 2 in H 2 O 2 @HSTC-1, the crystals were rinsed with catalase three times (5 ml each) to remove H 2 O 2 from the surface, and then treated with 3,3′,5,5′-tetramethyl-benzidine (TMB), a commonly used chromogenic agent for H 2 O 2 detection. 30,31 The results showed that HSTC-1 and H 2 O 2 @HSTC-1 barely changed in 30 minutes after the addition of TMB ethanol solution (400 μL, 0.2 M). By adjusting the pH value with buffer, the colour gradually changed from colourless to blue, and an obvious absorption peak appeared at 652 nm, while for HSTC-1 alone it did not.…”

Biomass‐Derived Porous Carbon as an Enzyme Mimic for Colorimetric Detection of Ascorbic Acid

“…Owing to the characteristics of low cost, high stability and excellent repeatability, artificial mimic enzymes have been widely explored for their great potential application ranging from medicine, food processing, environmental analysis, and biotechnology [1] . Various nanozymes have been verified to possess good peroxidase activity, such as metal oxides, [2] noble metal, [3] carbon nanomaterials, [4] metal‐organic frameworks [5] . The catalytic property of mimic enzymes is directly affected by composition, structure and morphology of nanomaterials [6] .…”

“…[1] Various nanozymes have been verified to possess good peroxidase activity, such as metal oxides, [2] noble metal, [3] carbon nanomaterials, [4] metal-organic frameworks. [5] The catalytic property of mimic enzymes is directly affected by composition, structure and morphology of nanomaterials. [6] Introducing heteroatoms, constructing heterojunction and dispersing in multi-dimensional materials are used in catalytic synergy, enhancement of adsorption capacity and acceleration of carrier transfer, enhancing the activity of mimic enzymes in previous works.…”

Coacervate-Based Plexcitonic Assembly toward Peroxidase-like Activity and Ultrasensitive Glucose Sensing

“…To date, different nanomaterials of transition-metal oxides and chalcogenides (Fe 3 O 4 , MoS 2 , CeO 2 , CuO, FeS 2 , etc. ), − noble metals (Ag, Au, Pt, Pd), ,,, carbon nanomaterials, , and metal–organic frameworks (MOFs) − have been found to possess intrinsic peroxidase-like activity. The peroxidase-like activity of these nanomaterials has been utilized successfully for the fabrication of low-cost colorimetric assays for the detection of various analytes including glucose, , H 2 O 2 , biothiols, and dopamine .…”