Hydrogen-Bonded Biohybrid Framework-Derived Highly Specific Nanozymes for Biomarker Sensing

Abstract

Nanozymes are of particular interest due to their enzyme-mimicking activity and high stability that are favorable in biomedical sensing and immunoassays. In this work, we report a highly specific N-doped nanozyme through pyrolysis of framework-confined bovine serum albumin (BSA). This strategy allows one to translate the low-cost and featureless BSA into a highly active enzyme mimic. The obtained carbon nanozyme (denoted as HBF-1-C800) displays 3-to 7-fold enhancement on peroxidase (POD) activity compared with the conventional carbon nanozymes and also shows ca. 5-fold activity enhancement compared to the reported N-doping graphene. Such excellent POD activity originates from high N-doping efficiency, protein-induced defective sites, and the intrinsic porous structure of HBF-1-C800, which provides abundantly accessible active sites and accelerates substrate diffusion simultaneously. Importantly, the HBF-1-C800 nanozyme has highly specific POD activity and also enables resistance to several harsh conditions that should denature natural enzymes. These features allow it with high accuracy, stability, and sensitivity for biosensing applications. Moreover, HBF-1-C800 has been designed as a promising platform for colorimetric biosensing of several biomarkers including H 2 O 2 , glutathione, and glucose, with wide linear ranges and low limits of detection that are satisfied with the disease diagnosis.

Insertion of Hemin into Metal–Organic Frameworks: Mimicking Natural Peroxidase Microenvironment for the Rapid Ultrasensitive Detection of Uranium

“…Upon addition of H 2 O 2 , high-spin signals and the low-spin signal diminished in intensity (Figure C), and a new peak at g = 2.01 was observed (Figure D), suggesting that both HS and LS Fe­[III] of hemin would bind with H 2 O 2 to yield an LS intermediate, resembling Compound I formation . Furthermore, in contrast to reported nanozymes, , hemin-based material , and hemin (Figure S10A), hydroxyl radicals and superoxide radicals were not detected during the catalytic process of ZIF- l -hemin (Figure S10B). Based on the results presented above, we concluded three characteristics of the catalytic mechanism for ZIF- l -hemin: (i) ping-pong reaction mechanism; (ii) iron porphyrin participates in the formation of reaction intermediates; (iii) no reactive oxygen species were generated, which were consistent with the proposed mechanism of the reaction of natural peroxidase …”

Metal Azolate Coordination Polymer-Enabled High Payload and Non-Destructive Enzyme Immobilization for Biocatalysis and Biosensing

“…3 The fly in the ointment is that enzymes are susceptible to harsh conditions, especially hyperthermia, strong acid or strong alkaline environments. 4,5 In addition, native enzymes are not conducive to recycling, which restricts their practical applications. 6,7 Strategies of simply trapping the enzymes in cages or anchoring them to the outermost layers were proposed.…”

“…Particularly, most of the enzymes work under facile reaction conditions with outstanding catalytic efficiency, high selectivity, and reaction rate far exceeding the artificial enzyme, which would foster the development of green chemistry . The fly in the ointment is that enzymes are susceptible to harsh conditions, especially hyperthermia, strong acid or strong alkaline environments. , In addition, native enzymes are not conducive to recycling, which restricts their practical applications. , Strategies of simply trapping the enzymes in cages or anchoring them to the outermost layers were proposed. , However, this often encounters low loading efficiency and insufficient protection. In this context, enzyme immobilization enabling activity preservation and improved recyclability is highly desirable.…”

Bioinspired Surface Modification of Graphene-Based Hybrids as Nanozyme Sensors for Simultaneous Detection of Dopamine and Uric Acid

“…Numerous studies have confirmed that nanozymes could overcome the obstacles of natural enzymes due to the advantages of the robustness under harsh conditions, superiorities of large-scale production, and tunability in catalytic activities. , Notably, oxidase mimics have gained plentiful eyes because they could be used without the assistance of destructive H 2 O 2 . As is known, nanozymes with oxidase-like activity are widely utilized in the colorimetric assay. , However, an inevitably problem is the severe interference color generated by nanozymes, which could obstruct the judgment of color . Enormous effects have been devoted to surmounting the problem by preparing white nanozymes.…”

“…4 As is known, nanozymes with oxidase-like activity are widely utilized in the colorimetric assay. 5,6 However, an inevitably problem is the severe interference color generated by nanozymes, which could obstruct the judgment of color. 7 Enormous effects have been devoted to surmounting the problem by preparing white nanozymes.…”