Single‐Atomic Site Catalyst with Heme Enzymes‐Like Active Sites for Electrochemical Sensing of Hydrogen Peroxide

Abstract

Heme enzymes, with the pentacoordinate heme iron active sites, possess high catalytic activity and selectivity in biosensing applications. However, they are still subject to limited catalytic stability in the complex environment and high cost for broad applications in electrochemical sensing. It is meaningful to develop a novel substitute that has a similar structure to some heme enzymes and mimics their enzyme activities. One emerging strategy is to design the Fe‐N‐C based single‐atomic site catalysts (SASCs). The obtained atomically dispersed Fe‐Nx active sites can mimic the active sites of heme enzymes effectively. In this work, a SASC (Fe‐SASC/NW) is synthesized by doping single iron atoms in polypyrrole (PPy) derived carbon nanowire via a zinc‐atom‐assisted method. The proposed Fe‐SASC/NW shows high heme enzyme‐like catalytic performance for hydrogen peroxide (H2O2) with a specific activity of 42.8 U mg−1. An electrochemical sensor based on Fe‐SASC/NW is developed for the detection of H2O2. This sensor exhibits a wide detection concentration range from 5.0 × 10−10 m to 0.5 m and an excellent limit of detection (LOD) of 46.35 × 10−9 m. Such excellent catalytic activity and electrochemical sensing sensitivity are attributed to the isolated Fe‐Nx active sites and their structural similarity with natural metalloproteases.

Comprehensive Review on Wearable Sweat-Glucose Sensors for Continuous Glucose Monitoring

“…Single-atomic site catalysts (SASCs), [86] containing exclusively isolated active metal sites, have aroused wide attention due to their specific activity and maximized atomic utilization. Among them, Fe-N-C-based SASCs [87] have a large amount of Fe-Nx active sites, which can mimic the structure of penta-coordinate heme iron systems in heme enzymes. Due to these unique features, Fe-N-C-based SASCs can enhance peroxidaselike catalytic activities and open new avenues to substitute the natural enzymes in the biosensing field.…”

Single‐Atomic Iron Doped Carbon Dots with Both Photoluminescence and Oxidase‐Like Activity

“…Therefore, more and more SANs have been reported and applied in sensing and detection. [30][31][32][33][34][35][36] Currently, some single-atomic Fe/C catalysts with high enzyme-like activity have been reported and applied for sensing, but these catalysts have poor dispersibility in aqueous solution, making them unsuitable for target sensing in aqueous matrices. In contrast, CDs can be well dispersed in water or buffers, and they appear to be the most effective carrier for loading metal single atoms in enzyme-like nanomaterials.…”

A MnOx enhanced atomically dispersed iron–nitrogen–carbon catalyst for the oxygen reduction reaction

“…S8 †) and previous reports. 40,41 The k 3 -weighted Fouriertransformed (FT) extended X-ray absorption ne structure (EXAFS) spectra (Fig. 4b) show that both SACs exhibit a prominent peak at around 1.42 Å, which is consistent with the Fe-N 4 peak from FePc, suggesting the presence of atomically dispersed Fe-N x sites.…”