Fabrication of FeS₂/SiO₂ Double Mesoporous Hollow Spheres as an Artificial Peroxidase and Rapid Determination of H₂O₂ and Glutathione

Abstract

Nanozymes as one of artificial enzymes show many advantages than natural enzymes. The high Michaelis−Menten constant (K m ) to H 2 O 2 is the drawback for nanozymes, which means a high H 2 O 2 concentration to oxidize 3,3′,5,5′-tetramethylbenzidine (TMB). For this problem, FeS 2 /SiO 2 double mesoporous hollow spheres (DMHSs) were first synthesized as an artificial peroxidase through a solid reaction. The experimental results demonstrate that Fe 3 O 4 vulcanization and DMHS formation were effective strategies to enhance affinity to H 2 O 2 for the nanozyme. The K m of FeS 2 /SiO 2 DMHSs (H 2 O 2 as the substrate) is 18-fold smaller than that of FeS 2 nanoparticles (NPs). The catalytic efficiency (K cat /K m ) of FeS 2 /SiO 2 DMHSs is about 16 times higher than that of FeS 2 NPs. FeS 2 /SiO 2 DMHSs can be used as a nanozyme to sensitively and rapidly detect H 2 O 2 and glutathione within 1 min at room temperature.

Sweetsop-like α-Fe2O3@CoNi catalyst with superior peroxidase-like activity for sensitive and selective detection of hydroquinone

“…2B , a characteristic signal peak of DMPO-HO˙ with an intensity of 1 : 2 : 2 : 1 was generated after the addition of α-Fe 2 O 3 @CoNi, indicating that α-Fe 2 O 3 @CoNi can catalyze H 2 O 2 to produce ˙OH. 49 Based on the experimental results and previous reports, the mechanism of the peroxide-like activity of α-Fe 2 O 3 @CoNi was proposed and illustrated in Fig. 7 .…”

Highly Sensitive Fluorescent Detection of Acetylcholine Based on the Enhanced Peroxidase-Like Activity of Histidine Coated Magnetic Nanoparticles

“…The Lineweaver-Burk plots then were applied to determine K m and V max . Table 1 summarized the catalytic parameters of His@MNPs, unmodified pristine MNPs, HRP, and other peroxidase-like nanozymes which were recently reported [ 2 , 3 , 11 , 16 , 31 ]. According to the Table 1 , it is noticeable that the K m value (TMB) for His@MNPs was approximately 3 times higher than that of natural HRP.…”

Nanozymes in Tumor Theranostics

“…Simultaneously, the peroxidase activity of FeS 2 NSs can be tunable by pH and temperature ( 49 ). The FeS 2 /SiO 2 double mesoporous hollow spheres (DMHSs) not only exhibit a more outstanding POD-like activity than both Fe 3 O 4 NPs and FeS 2 NSs, but also are more susceptive to the detection of H 2 O 2 and glutathione (GSH) ( 50 ). The sulfur vacancies in magnetic greigite (SVs-Fe3S4) NSs have demonstrated a distinguished POD-mimic activity resulting from the abundant SVs, which have been developed for the colorimetric detection of glucose in human serum ( 51 ).…”