Rational design of cuprofullerene bipyridine nanozyme with high peroxidase-like activity for colorimetric sensing of bleomycin.

The high catalytic activity of Cu-based nanozymes mainly depends on the efficient Fenton-like reaction of Cu + / H 2 O 2 , but Cu + cannot exist stably. Trying to find a material that can stably support Cu + while promoting the electron cycle of Cu 2+ /Cu + still faces serious challenges. C 60 is expected to be an ideal candidate to solve this problem due to its unique structure and rich physicochemical properties. Here, we designed and synthesized a C 60 -doped Cu + -based nanozyme (termed as C 60 -Cu-Bpy) by loading high catalytic active site Cu + onto C 60 and coordinating with 2,2'-bipyridine (Bpy). The single crystal diffraction analysis and a series of auxiliary characterization technologies were used to demonstrate the successful preparation of C 60 -Cu-Bpy. Significantly, the C 60 -Cu-Bpy exhibited superior peroxidase-like activity during the catalytic oxidation of 3,3',5,5'-tetramethylbenzidine (TMB). Then, the catalytic mechanism of C 60 -Cu-Bpy as peroxidase was elucidated in detail, mainly benefiting from the dual function of C 60 . On the one hand, C 60 acted as a carrier to directly support Cu + , which has the ability to efficiently decompose H 2 O 2 to produce reactive oxygen species. The other was that C 60 acted as an electron buffer, contributing to promoting the Cu 2+ /Cu + cycle to facilitate the reaction. Furthermore, a colorimetric sensor for the quantitative analysis of bleomycin was established based on the principle of bleomycin specific inhibition of C 60 -Cu-Bpy peroxidase-like activity, with satisfactory results in practical samples. This study provides a new strategy for the direct synthesis of Cu + -based nanozymes with high catalytic performance.