Fabrication of hierarchical 3D layered yttrium hydroxide nanocomposites: Their use for enzyme immobilization and catalysis of H2O2

[Display omitted] •The hierarchical 3D AuNPs/LYH nanocomposites have been fabricated for enzyme immobilization.•The AuNPs/LYH nanocomposites possess excellent biocompatibility and enhanced electrical conductivity.•The synergistic effect of LYHs and AuNPs improves the electrochemical responses of the HRP biosensor towards H2O2.•The prepared biosensors exhibit excellent quantitative capability for detecting H2O2 in real water samples. 3D layer metal hydroxides (LMHs) have attracted significant interest due to their distinctive structural features. Unfortunately, the limited electrical conductivity hinders the potential utilization of LMHs in electrochemical analysis. To address this issue, herein, gold nanoparticles (AuNPs) were introduced to layered yttrium hydroxides by a facile in-situ electrodeposition method. Subsequently, the hierarchical AuNPs/LYH nanocomposite was employed as solid supports for immobilization of horseradish peroxidase, generating an enzymatic biosensor for hydrogen peroxide detection. As a result, a linear range of 1–500 μM with a remarkably low detection limit of 0.33 μM (S/N=3) was achieved. Moreover, the biosensor also demonstrated excellent selectivity, reproducibility and stability. The superior electrochemical responses of the HRP/AuNPs/LYH nanocomposite towards H2O2 can be ascribed to the synergistic effect arising from the flower-like structures of LYHs and the high conductivity of AuNPs. Our study provides a significant approach for the development of enzyme immobilized supports through the construction of layer metal hydroxide nanocomposites.