Self‐assembled CoSe₂ Microspheres with Intrinsic Peroxidase Mimicking Activity for Efficient Degradation of Variety of Dyes

Abstract

In this investigation, we report a new and greener self‐assembly of CoSe2 microsphere (CoSe2 MS) without assistance of harmful reducing and structure‐directing agents (SDA). Intrinsic peroxidase mimicking activity of synthesized CoSe2 MS was evaluated for 3,3,5,5′‐tetramethylbenzidine as a substrate by monitoring the absorbance of oxidized product at 653 nm. The smaller Michalis Menten constant (Km) for CoSe2 MS catalyzed reaction (0.371 mM), than the natural Horse Radish Peroxidase (HRP) enzyme, signifies the high substrate affinity of CoSe2 MS than HRP. Further, intrinsic peroxidase activity was assessed using emission intensity enhancement of terephthalic acid (TA) in presence of CoSe2 MS and H2O2 with time due to the production of .OH radicals and subsequent hydroxylation of TA. CoSe2 MS was further employed for organic dyes degradation in presence of H2O2, where cationic and anionic dyes degraded within 120 min with the highest degradation efficiency of 99.45 % for malachite green.

What are inorganic nanozymes? Artificial or inorganic enzymes

“…Transition metal sulfite and selenide nanoparticles have also been shown to have intrinsic POD or other oxidoreductase-like activity, e.g., FeS, 133 Fe 7 S 8 , 134 Fe 3 S 4 , 135 iron polysulfides, 136 CuS, 137 CuZnFeS, 138 CdS, 139 MoS 2 , 140 WS 2 , 141 FeSe, 142 a-MnSe, 142 MoSe 2 , 143 and CoSe 2 . 144 All their catalysis kinetics can be described by the Michaelis-Menten equation with a relatively low K m , compared to the natural enzymes and even the corresponding oxide nanoparticles, 7 as the inorganic phosphatases were to PAPs, which further implies that these inorganic PODs served as primitive PODs in the more anoxic early ocean. Such inorganic enzymes also have some architectural links with another big family of enzymes, iron-sulfur proteins, with a cluster of multinuclear iron and inorganic sulfide, where the irons are coordinated by protein amino acid residues and sulfides with such a function.…”

Introductory Chapter: Incredible Spicy Iron Oxide Nanoparticles

“…Greigite (Fe 7 S 8 ), as an example, was detected in the laboratory under the simulated early Earth hydrothermal conditions [92]. Some of them were documented to have "intrinsic peroxidase" "intrinsic superoxide dismutase," and/ or "intrinsic catalase" activity, e.g., Fe 3 S 4 [93], Fe 7 S 8 [94], CuS [95], CuZnFeS [96], CdS [97], MoS 2 [98], WS 2 [99], FeS [100], FeSe [100], α-MnSe [101], MoSe 2 [102], and CoSe 2 [103]. It is not strange since many iron-sulfur proteins contain a cluster of multinuclear iron and inorganic sulfide, where the irons are coordinated by protein amino acid residues and sulfides with such function [104][105][106], e.g., alkyl hydroperoxide reductase with a disulfide bond structure [107].…”

CoSe2 Nanoparticles with Multienzymic Activities for Antibacterial Applications

“…Recently, CoSe 2 was reported as a nanoenzyme with peroxidase (POD) mimicking activity in the detection of glutathione and dye degradation. , Similarly, a highly specific and sensitive colorimetric test for the detection of H 2 O 2 and glucose was established using CoSe 2 /reduced graphene oxide (CoSe 2 /rGO) nanohybrids, which were revealed to contain intrinsic POD-like catalytic activity . For cancer treatment, CoSe 2 nanosheets with vacancy associates were synthesized by changing the templates and calcination temperatures .…”