A new strategy based on the graphite phase carbon nitride/non-integral bismuth oxychloride/bismuth oxybromide (g-C₃N₄/BiOCl_0.5Br_0.5) heterojunction and the plasma resonance effect of gold nanoparticles (AuNPs) was developed to construct a novel AuNPs/g-C₃N₄/BiOCl_0.5Br_0.5/ITO sensitized photoelectrochemical sensor for rapid and sensitive detection of plant hormone 2-chloroethyl phosphate (ETH). The morphology structure of the as-prepared materials and the characteristics of electrode film were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS), and the photoelectrochemical response to ETH of the sensor was studied by electrochemical impedance spectroscopy (EIS) and current-time curve (i-t), etc. Density functional theory (DFT) was used to calculate the charge density of atoms in the g-C₃N₄/BiOCl_0.5Br_0.5 heterojunction, the electronic transition mechanism was analyzed, and the sensor's sensitization mechanism was further proposed. Furthermore, the relationship between the change of the sensor's transient current and the concentration of ETH was studied. Under the optimal conditions, ETH concentration in the range of 20.00 nmol/L–63.00 μmol/L had a good linear relationship with photocurrent, and the AuNPs/g-C₃N₄/BiOCl_0.5Br_0.5/ITO sensor exhibited high stability and high reproducibility. This study provided a feasible solution for the rapid and efficient detection of ETH, as well as a new sensing platform for detection of other plant hormones.

提出了一种基于石墨相氮化碳/非整体式三氧化二铋/溴化铋（gC ₃ N ₄ / BiOCl _0.5 Br _0.5）异质结和金纳米颗粒（AuNPs）的等离子体共振效应的新策略，以构建新型的AuNPs / gC ₃ N ₄ / BiOCl _0.5 Br _0.5/ ITO敏化光电化学传感器，用于快速灵敏地检测植物激素2-氯乙基磷酸酯（ETH）。通过扫描电子显微镜（SEM），X射线衍射（XRD）和能量色散光谱（EDS）表征了所制备材料的形态结构和电极膜的特性，并且传感器对ETH的光电化学反应为通过电化学阻抗谱（EIS）和电流时间曲线（i - t）等进行研究。使用密度泛函理论（DFT）计算gC ₃ N ₄ / BiOCl _0.5 Br _0.5中原子的电荷密度。异质结，分析了电子跃迁机理，并进一步提出了传感器的敏化机理。此外，研究了传感器瞬态电流的变化与ETH浓度之间的关系。在最佳条件下，ETH浓度在20.00 nmol / L–63.00μmol/ L范围内与光电流具有良好的线性关系，AuNPs / gC ₃ N ₄ / BiOCl _0.5 Br _0.5 / ITO传感器显示出高稳定性和高再现性。这项研究为快速有效地检测ETH提供了可行的解决方案，并为检测其他植物激素提供了新的传感平台。