In this work, a silicon nanoparticles (Si NPs)-based ratiometric fluorescence sensing platform was conveniently fabricated by simply mixing fluorescent Si NPs as co-ligands and reference signal with lanthanide metal ion Eu³⁺ as response signal. The introduction of ciprofloxacin (CIP) remarkably turned on the characteristic fluorescence of Eu³⁺ at 590 nm and 619 nm through the “antenna effect”. At the same time, the blue emission of Si NPs at 445 nm kept comparatively stable. A good linear relationship between the ratio fluorescence intensity and CIP concentration in the range of 0.211–132.4 μM with a limit of detection (LOD) of 89 nM was obtained. In the presence of Cu²⁺, the fluorescence emission of Eu³⁺ was sharply turned off because of the stronger coordination ability of Cu²⁺ with CIP, which guaranteed the sequential detection of Cu²⁺. Meanwhile, the distinct fluorescent color change from bright blue to red, then back to blue, enabled naked-eye visual detection of CIP and Cu²⁺ in the solution phase and on paper-based test strip, and was successfully applied to determine the levels of CIP in complicated food samples with high sensitivity.

在这项工作中，通过简单地将荧光Si NPs作为共配体和参考信号与镧系金属离子Eu ³⁺作为响应信号混合，可以方便地制造基于硅纳米颗粒（Si NPs）的比率式荧光传感平台。环丙沙星（CIP）的引入通过“天线效应”显着开启了Eu ³⁺在590 nm和619 nm处的特征荧光。同时，Si NP在445 nm处的蓝光发射保持相对稳定。获得的荧光强度与CIP浓度之比在0.211–132.4μM之间具有良好的线性关系，检出限（LOD）为89 nM。在Cu ²⁺的存在下，Eu ³⁺的荧光发射由于Cu ²⁺与CIP具有更强的配位能力，因此可以将Cu ²⁺急剧关闭，从而保证了对Cu ²⁺的顺序检测。同时，明显的荧光颜色从亮蓝色变为红色，然后变为蓝色，从而可以在溶液相和纸基试纸上用肉眼目测CIP和Cu ²⁺，并成功地用于确定含量复杂食品中CIP的检测具有很高的灵敏度。