基于Au@BiOBr/MWNTs的光电化学传感器超灵敏检测过氧化氢

The Photoelectrochemical Sensor Based on Multiwall Carbon Nanotubes/Au@BiOBr for Ultra-Sensitive Detection of Hydrogen Peroxide

摘要: 目的：本研究通过水热法合成金纳米粒子(Au NPs)和溴氧化铋(BiOBr)，采用共价改性法对多壁碳纳米管(MWNTs)进行氧化处理，制备Au@BiOBr/MWNTs复合材料，从而对过氧化氢进行光电化学检测。在可见光照射下，Au@BiOBr/MWNTs检测过氧化氢时有明显的光电流响应，主要的原因是，Au NPs会产生局域表面等离子效应(LSPR)以及BiOBr产生光生电子–空穴对，能够吸附溶液中的H₂O₂到电极表面并对其进行氧化，增强光电流。MWNTs具有优异的导电性能，能够促进电子转移，有效抑制电子–空穴的复合。该光电传感器检测过氧化氢时的浓度范围5~60 μmol/L，检出限为1.7 μmol/L，表明复合材料对过氧化氢有较好的检测效果。该Au@BiOBr/MWNTs光电化学传感器具有稳定性好、灵敏度高等优点，对过氧化氢的检测具有重要的意义，期待其在监测细胞内活性氧(ROS)水平方面具有广阔的应用前景。

Abstract: Purpose: In this study, Au nanoparticles (Au NPs) and bismuth bromide (BiOBr) were synthesized by hydrothermal method and multiwalled carbon nanotubes (MWNTs) were oxidized by covalent modification method to prepare Au@BiOBr/MWNTs composites, which were used for photoelectrochemical detection of hydrogen peroxide. Under visible light irradiation, Au@BiOBr/MWNTs have a significant photocurrent response when detecting hydrogen peroxide, mainly because Au NPs produce localized surface plasmon effects (LSPR) and BiOBr produces photogenerated electron-hole pairs, which can absorb H₂O₂ in solution to the electrode surface and oxidize H2O2, increasing the photocurrent. MWNTs have excellent electrical conductivity, which can promote electron transfer and effectively inhibit electron-hole recombination. The photoelectric sensor detects hydrogen peroxide in the concentration range of 5~60 μmol/L with a detection limit of 1.7 μmol/L, indicating that the composite material has a good detection effect on hydrogen peroxide. The photoelectrochemical sensor has the advantages of good stability and high sensitivity, which is of great significance to the detection of hydrogen peroxide, and it is expected to have promising applications in monitoring intracellular reactive oxygen species (ROS) levels.