RhB@ZrT-1-OH composite was constructed by introduction of Rhodamine B (RhB) into the cages of zirconium-based metal–organic cage that had two fluorescence emission peaks at 466 and 612 nm upon excitation at 327 nm. The dual-emission fluorescence sensor exhibits ultra-high sensitive detection for malachite green (MG) and glycine (Gly) in phosphate buffer solution (pH = 6.86). RhB@ZrT-1-OH as a ratiometric fluorescence probe was applied to detect MG with a low LOD of 0.2879 μM and presented obvious fluorescence visual changes from orange to purple to blue under 254 nm UV–vis lamp. Moreover, RhB@ZrT-1-OH also can be utilized as a “turn-on” fluorescence sensor to recognize Gly with a low LOD of 0.3747 μM and exhibits fluorescence color changes from orange to pink to purple. Notably, the corresponding test papers for sensing MG and Gly were designed for recognize the concentration of MG and Gly. Furthermore, the dual-emission fluorescence sensor can be used to detect MG and Gly in fish and human serum with high sensitivity and reliable. The possible detecting mechanisms of RhB@ZrT-1-OH for sensing MG and Gly were detailedly explored.

RhB@ZrT-1-OH 复合材料是通过将罗丹明 B (RhB) 引入锆基金属有机笼的笼中构建的，该笼在 327 nm 激发下在 466 和 612 nm 处具有两个荧光发射峰。双发射荧光传感器对磷酸盐缓冲溶液 (pH = 6.86) 中的孔雀绿 (MG) 和甘氨酸 (Gly) 具有超高灵敏度检测。RhB@ZrT-1-OH作为比率荧光探针用于检测MG，LOD为0.2879 μM，在254 nm紫外-可见灯下呈现明显的从橙色到紫色到蓝色的荧光视觉变化。此外，RhB@ZrT-1-OH 还可用作“开启”荧光传感器，以识别低LOD的 Gly为 0.3747 μM，荧光颜色从橙色变为粉红色再到紫色。值得注意的是，相应的检测MG和Gly的试纸是为识别MG和Gly的浓度而设计的。此外，双发射荧光传感器可用于检测鱼和人血清中的MG和Gly，灵敏度高且可靠。详细探讨了RhB@ZrT-1-OH检测MG和Gly的可能机制。