【目的】寻找一种可以简单快速检测液样中残留氧氟沙星(OFL)的方法,扩大铜纳米簇的应用领域,也为便携式试纸或试盒的开发提供新的理论基础。【方法】以谷胱甘肽(GSH)为稳定剂,利用一锅法合成具有良好水溶性和优异光学性质的铜纳米簇(CuNCs)。在酸性体系中,当激发波长为340 nm时,GSH-CuNCs和OFL分别在425和510 nm处有最大发射峰;检测体系中出现OFL时,510 nm处发射峰的荧光增强,425 nm处略有降低。利用该体系在510和425 nm处荧光强度比值的变化,构建了一种简单、快速、灵敏和选择性好的比率型荧光探针用于环境中残留OFL的检测。【结果】在最优检测条件下,体系的ΔF₅₁₀/F₄₂₅值与OFL在残留浓度0.005~10.000 μmol/L范围内线性关系良好,检出限(LOD)为1.5 nmol/L(信噪比S/N=3)。该荧光探针可以用于实际水体和牛奶中OFL的检测,加标回收率为93.6%~103.3%,相对标准偏差(RSD)均低于10%。【结论】本方法具有成本较低、操作简便、迅速、灵敏度高和选择性好等优点,可以实现快速灵敏地检测实际样品中残留的OFL,具有良好的实用性。

【Objective】This study aims to develop a simple, rapid and sensitive fluorescence detection method for residual ofloxacin (OFL) in liquid samples, broaden the applications of copper nanoclusters and providing a theoretical foundation for portable diagnostic devices.【Method】A one-pot synthesis method was employed to prepare glutathione-stabilized copper nanoclusters (GSH-CuNCs) with excellent water solubility and optical properties. In an acidic condition, GSH-CuNCs and OFL have maximum emission peaks at 425 nm and 510 nm respectively upon excitation wavelength at 340 nm. With OFL, the green fluorescence intensity of the system at 510 nm was significantly enhanced compared to GSH-CuNCs, meanwhile the blue fluorescence intensity at 425 nm was slightly decreased. Thus, a GSH-CuNCs-based ratiometric fluorescent probe was constructed for the simple rapid, sensitive and selective detection of residual OFL in the enviroment.【Result】After optimization of the experimental conditions, the ratiometric fluorescent probe exhibited a linear response to OFL concentrations in the range of 0.005-10.000 μmol/L, with a detection limit (LOD) of 1.5 nmol/L. This ratiometric probe has been applied to detect OFL in the actual spiked water and milk samples. Applying with spiked real sample, the recovery rate of OFL was 93.6%-103.3%, and relative standard deviations (RSD) were all less than 10%.【Conclusion】The developed ratiometric fluorescent probe offers the advantages of simplicity, low cost, high sensitivity, and excellent selectivity, enabling rapid and accurate detection of residual ofloxacin in real-world applications.