目的：本研究通过水热法合成了花状溴氧化铋(BiOBr)和金纳米粒子(Au NPs)，利用超声复合法制备Au@WP5 (水溶性柱[5]芳烃)功能化BiOBr复合材料(Au@WP5/BiOBr)，将其应用与对咖啡酸的超灵敏性检测。在可见光照射下，Au@WP5/BiOBr检测咖啡酸时有显著的光电流响应，这主要是由于在可见光照下WP5和咖啡酸之间的主客体络合可提高咖啡酸分子在Au@WP5/BiOBr上的吸附，Au NPs产生的局域表面等离子效应(LSPR)、BiOBr产生的光生空穴可以加速咖啡酸分子的氧化，同时产生的高浓度的高能载流子既可以抑制电子–空穴对的复合又能提高氧化峰电流，最终实现对咖啡酸的超灵敏性检测。该光电传感器检测咖啡酸时的浓度范围在1.74~190 μmol/L之间，检出限为0.58 μmol/L，表明Au@WP5/BiOBr对咖啡酸具有较好的催化效果。该光电化学传感器具有高效、响应迅速和重复性好等优点，对酚类化合物的检测具有重要意义，在生物小分子光催化方面具有广阔的应用前景。 Purpose: In this study, flower-like bismuth bromide oxide and gold nanoparticles (Au NPs) were synthesized by hydrothermal method, using ultrasonic method to obtain Au@WP5 (water-soluble column [5] aromatic hydrocarbon) and BiOBr heterojunction composite materials. The photochemical platform for the ultra-sensitive detection of caffeic acid was established based on Au@WP5/BiOBr. The photocurrent response of Au@WP5/BiOBr in caffeic acid photocatalysis under visible light irradiation was obviously enhanced because the host-guest complexation between WP5 and caffeic acid can improve the adsorption of caffeic acid on the Au@WP5/BiOBr under visible light, the localized surface plasmon resonance (LSPR) effect of Au NPs as well as the BiOBr was benefitted to assist the oxidation of the caffeic acid molecules, and inhibit the recombination of electron-hole pairs and enhance the oxidation current by the high-energy carriers, thus leading to the excellent detection of caffeic acid. The detection range of the photoelectrochemical sensor for caffeic acid was between 1.74 μmol/L and 190 μmol/L, and the detection limit was 0.58 μmol/L, indicating that Au@WP5/BiOBr had a good detection for caffeic acid. The photocatalysis has the advantages of high efficiency, prompting response and good stability, and has potential significance in the analysis of phenolic compounds in organisms. It is expected to have a broad application prospect in photocatalysis of small biomolecules.