Gold nanoparticles-wood nanohybrid as peroxidase-like for simple and selective detection of mercury ion

We present the design and synthesis of a gold nanoparticle-wood nanohybrid (AuNPs@Wood), synthesized via the in-situ growth of gold nanoparticles (AuNPs) within a hierarchical wood flour nanostructure under mild conditions. The AuNPs@Wood exhibited remarkable peroxidase-like activity, attributed to the unique hierarchical architecture of the wood flour. Furthermore, the use of AuNPs@Wood in conjunction with T-rich DNA (P1) results in the development of a label-free colorimetric approach for detecting mercury ions. The peroxidase-like activity of the AuNPs@Wood–P1 system was found to increase with rising concentrations of Hg (II), demonstrating a linear response to Hg (II) concentration with a correlation coefficient of 0.9917. The detection limit for Hg (II) was determined to be 0.016 μM based on three times the standard deviation (σ). Additionally, sensing Hg²⁺ ions remained unaffected by other metal ions, underscoring the exceptional selectivity of AuNPs@Wood–P1. In comparison to traditional methods, this approach offers advantages such as high selectivity, sensitivity, cost-effectiveness, and ease of operation without requiring complex instrumentation, thereby presenting significant potential for biosensing applications.