DNA Framework-Templated Synthesis of Copper Cluster Nanozyme with Enhanced Activity and Specificity

Abstract

Nanozymes have been developed to overcome the inherent limitations of natural enzymes, such as their low stability and high cost. However, their efficacy has been hindered by their relatively low specificity and activity. Here, we demonstrate the self-assembly of individual copper nanoclusters (CuNCs) via a simple yet fast (10 min) DNA nanosheet (DNS)-templated method, enhancing the peroxidase-like activity and specificity of CuNCs. Furthermore, we demonstrate the successful assembly of CuNCs on different DNA nanostructures by atomic force microscopy (AFM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The resulting micron-scale ultrathin DNA nanosheet-templated CuNCs (DNS@CuNCs) exhibit exceptional catalytic activity, with a specific activity reaching 1.79 × 10³ U mg^-1. Investigation into the catalytic process reveals that the enhanced activity and specificity arise from disparities in active intermediate content before and after CuNCs assembly. Significantly, the DNS@CuNCs-based biosensor demonstrates remarkable anti-interference capabilities, enabling the detection of H₂O₂ in undiluted human serum for the first time with a detection limit of 0.99 μM.