2D/3D-Shaped Fe_0.8Ni_0.2S₂/ZIF-67 as a Nanozyme for Rapid Measurement of H₂O₂ and Ascorbic Acid with a Low Limit of Detection

Abstract

Metal–organic frameworks (MOFs) can be used as ideal artificial nanozymes for an open structure to transfer substances and products. The nanozymic mechanism of MOFs needs further investigation for wide application. In this manuscript, no peroxidase-like activity was found for ZIF-67 (a kind of MOF), however, it enhanced the peroxidase-like activity of the Fe0.8Ni0.2S2/ZIF-67 composite, in which Fe0.8Ni0.2S2 was the active composition. The catalytic constant (K cat) is higher at 1.98 (for TMB) and 2.08 (for H2O2) times and the catalytic efficiency (K cat/K m) is higher at 3.13 (for TMB) and 2.67 (for H2O2) times, than those of Fe0.8Ni0.2S2. The K m value decreased about 85 times (for H2O2) for Fe0.8Ni0.2S2/ZIF-67 than that of horseradish peroxidase (natural enzyme). The mechanism was proposed. The limit of detection of H2O2 for Fe0.8Ni0.2S2/ZIF-67 is 0.039 μM, which is lower by about 18.2 times than that of Fe0.8Ni0.2S2. Simultaneously, Fe0.8Ni0.2S2/ZIF-67 was used to rapidly detect ascorbic acid for only 1.0 min in food monitoring. This study may be important to design a new kind of nanozyme.

Peroxidase-like activity of hollow sphere-like FeS2/SC boosted by synergistic action of defects and S–C bonding

“…The characterization was similar to what we reported, 14 such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive spectroscopy (EDX), specific surface area analysis, X-ray photoelectron spectroscopy (XPS), UV-visible spectroscopy, etc . The contents of the carbon materials in FeS 2 /SC were obtained based on the measurement of the concentration of Fe by inductively coupled plasma atomic emission spectroscopy (ICP-AES, Optima 7300 DV, PerkinElmer).…”

“…11 A porous structured composite (FeS 2 /SiO 2 ) showed higher POD-like activity than FeS 2 . 12 As reported, 13,14 the POD-like activity was enhanced by improving the electron transfer of the nanozyme. So, the replacement of SiO 2 by excellent electron transport materials may further enhance the POD-like activity.…”

“…The high absorbance value of the solution at 652 nm means the high activity of the nanozyme. 14 The carbon content in FeS 2 /SC affects the activity. The order of the activity from high to low is FeS 2 /SC-5.0% > FeS 2 /SC-7.5% > FeS 2 /SC-2.5% > FeS 2 /SC-10.0% > FeS 2 > FeS 2 / SC-12.5%.…”

Dye encapsulation and one-pot synthesis of microporous–mesoporous zeolitic imidazolate frameworks for CO2 sorption and adenosine triphosphate biosensing

“…They exhibit no fluorescence emission. However, several methods have been reported via the encapsulation of aggregation-induced emission (AIE) gold nanocrystals, 6 gold nanoparticles, 7 carbon dots (CDs)/safranine T, 8 MnO 2 /CDs, 9 MnO 2 -AuNCs@ZIF-8, 10 Fe 0.8 Ni 0.2 S 2 , 11 quantum dots, 12 and enzymes. 13 ZIF-8 improved the sensitivity of CDs/ST by 69 fold enabling naked-eye detection of analytes such as tetracycline (TC) antibiotics.…”

Dual mimic enzyme properties of Fe nanoparticles embedded in two-dimensional carbon nanosheets for colorimetric detection of biomolecules

“…FeS NSs and graphene oxide), and three-dimensional (3D) metal-organic framework materials (MOFs) (e.g. MIL-53(Fe), MIL-47(V), and ZIF-8) [16][17][18] have been utilized as oxidase-like and peroxidaselike nanozymes in the construction of sensing platforms for the assay of H 2 O 2 , 19,20 glucose, 21,22 glutathione (GSH), 23,24 cancer cells 25,26 and so on. However, the catalytic activity of some nanozymes would be depressed in serum, urine, or living cell samples.…”