Wang Jian, Ye Bo, Xiao Shiqi, Liu Xia
School of Chemistry, Southwest Jiaotong University Chengdu 610031 China
College of Life Science and Engineering, Southwest Jiaotong University Chengdu 610031 China.
RSC Adv. 2024 Jan 16;14(4):2697-2703. doi: 10.1039/d3ra07421h. eCollection 2024 Jan 10.
The active site accessibility and high loading of gold nanoparticles (AuNPs) are key factors affecting the catalytic activity of supported AuNP-based catalysts. However, the preparation of supported AuNP-based catalysts with highly accessible active sites still remains a challenge. Herein, sphere-on-sphere (SoS) silica microspheres with a hierarchical structure, good dispersion and high surface density of thiol groups (10 SH nm) are prepared and used as a platform for the growth of high-density AuNPs. The obtained hierarchical Si@Au micro-/nanostructure consisting of 0.55 μm SoS silica microspheres and 7.3 nm AuNPs (SoS-0.55@Au-7.3) is found to show excellent peroxidase-mimicking activity ( = 0.033 mM and = 34.6 × 10 M s) with merits of high stability and good reusability. Furthermore, the as-obtained SoS-0.55@Au-7.3-based system can sensitively detect hydrogen peroxide (HO) with a low detection limit of 1.6 μM and a wide linear range from 2.5 μM to 1.0 mM. The high catalytic activity, excellent stability and good reusability of SoS-0.55@Au-7.3 imply its great prospects in biosensing and biomedical analysis.
金纳米颗粒（AuNPs）的活性位点可及性和高负载量是影响负载型AuNP基催化剂催化活性的关键因素。然而，制备具有高可及活性位点的负载型AuNP基催化剂仍然是一个挑战。在此，制备了具有分级结构、良好分散性和高表面硫醇基团密度（10个SH/nm）的球上球（SoS）二氧化硅微球，并将其用作高密度AuNPs生长的平台。由0.55μm的SoS二氧化硅微球和7.3nm的AuNPs组成的所得分级Si@Au微/纳米结构（SoS-0.55@Au-7.3）被发现具有优异的过氧化物酶模拟活性（米氏常数 = 0.033 mM，催化效率 = 34.6 × 10³ M⁻¹ s⁻¹），具有高稳定性和良好的可重复使用性。此外，所获得的基于SoS-0.55@Au-7.3的体系能够灵敏地检测过氧化氢（H₂O₂），检测限低至1.6 μM，线性范围宽，从2.5 μM到1.0 mM。SoS-0.55@Au-7.3的高催化活性、优异稳定性和良好的可重复使用性意味着其在生物传感和生物医学分析方面具有广阔前景。
