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

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 CO 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 HO, achieving a detection limit of 2.40 μM. The findings suggest that CuSANs can confer enhanced sensitivity to HO, which is essential for oxidative stress assessment, reaching values up to 130.0 μA mM cm.