One-Step Synthesis of Copper Single-Atom Nanozymes for Electrochemical Sensing Applications

Abstract
Single-atom nanozymes (SANs) combine the natural enzymatic properties of nanomaterials with the atomic distribution of metallic sites over a suitable support. Unfortunately, their synthesis is complicated by some key factors, like poor metallic loading, aggregation, time consumption, and low yield. Herein, copper SANs, with a surface metal loading (1.47% ± 0.16%) are synthesized, through a green, facile, minimal solution processing, single-step procedure, using a CO2 laser to promote the anchoring of the metallic precursor while simultaneously generating the laser-scribed graphene (LSG) support out of a polyimide sheet. The presence of the atomic Cu on the LSG surface is verified using high-angle-annular dark-field–scanning transmission electron microscopy and X-ray photoelectron spectroscopy. To explore the advantages incurred by the incorporation of Cu SANs on LSG, the material is used as a working electrode on an electrochemical sensor for the amperometric detection of H2O2, achieving a detection limit of 2.40 μM. The findings suggest that CuSANs can confer enhanced sensitivity to H2O2, which is essential for oxidative stress assessment, reaching values up to 130.0 μA mM−1 cm−2.

Acknowledgements
This work was supported financially by King Abdullah University of Science and Technology (KAUST), Saudi Arabia. In addition, the authors acknowledge funding from the KAUST smart health initiative. The authors thank Abdullah Bukhamsin for his generous support in electrochemical impedance spectroscopy studies and editing. G.T.B. is thankful to Professor Derya Baran for providing facilities to conduct the blade coating of the materials.

Publisher
Wiley

Journal
Small Science

DOI
10.1002/smsc.202300259

Additional Links
https://onlinelibrary.wiley.com/doi/10.1002/smsc.202300259

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