Fe Single-Atom Nanozymes for Real-Time Dual Monitoring of H₂O₂ Released from Living Cells

Abstract

Excessive accumulation of hydrogen peroxide (H2O2) in the physiological pool can cause oxidative stress of cells and eventually lead to the occurrence of diseases. Therefore, accurate and real-time detection of H2O2 is of great significance for disease detection and prevention. In this study, an Fe single-atom nanozyme (Fe-SNC) with an Fe-N4 active center was synthesized, which showed excellent peroxidase-like activity in an acidic environment and amazing electrocatalytic activity in H2O2 reduction reaction. Based on this, we proposed a colorimetric and electrochemical dual-signal detection strategy to real-time monitor H2O2 secreted by living cells. Compared with single-signal response mode, double-signal response mode has higher precision and sensitivity. The results show that the detection range of the colorimetric analysis method is 3–1000 μM and the detection limit is 1.3 μM. The detection range of the electrochemical analysis method is 1–8127 μM, and the detection limit is 0.61 μM. We believe that the dual-signal detection strategy based on Fe-SNC not only provides a way for the ultra-sensitive detection of hydrogen peroxide but also has a broad application prospect in clinical diagnosis.

Pt Single-Atom Catalyst on Co3O4 for the Electrocatalytic Detection of Glucose

“…With precisely defined active centers, SACs exhibit heightened reactivity and selectivity, showcasing exceptional performance in catalytic reactions. Moreover, the robust interaction between single atoms and supports stabilizes the former, effectively modulating their electronic structures and significantly enhancing catalytic activity and selectivity. , Additionally, SACs feature well-defined active centers that enable precise control over reaction pathways, resulting in heightened selectivity and reduced byproduct formation in specific reactions. While the utilization of SACs in electrochemical sensing is still in its infancy, unresolved issues persist regarding sensing performance and mechanisms .…”

Two-Dimensionally Ordered Carbon Array Nanostructures with Atomically Dispersed Nickel for Sensitive Nonenzymatic Detection of Glucose

“…One of the most important factors affecting the detection performance of enzyme-free electrochemical sensors is the sensing material. − The single-atom nanozyme is a new sensing material recently discovered . Compared with the previously reported nanozymes, the single-atom nanozymes have the characteristics of high atom utilization and strong activity; especially, the clear coordination structure provides an ideal model for exploring the structure–activity relationship. − The unique properties of single-atom nanozymes have attracted increasing attention in the field of electrochemical sensing. − For example, Zeng et al designed a single-atom Pt supported on Ni­(OH) 2 nanoplates/nitrogen-doped graphene for electrochemical nonenzymatic glucose sensing, where a Pt single atom induced more positive charge on Ni atoms and made Ni atoms exhibit stronger binding energy with glucose . Li et al synthesized Fe single atoms on 2D N-doping graphene for electrochemical detection of H 2 O 2 , where the bridge adsorption of O–O on Fe single atoms made the sensor exhibit an extremely high sensitivity …”