Highly sensitive and selective L-lactate monitoring in complex matrices with a ratiometric fluorescent sensor RhB@Zn-MOF

L-lactate is an essential biomarker in clinical diagnostics and food quality assessment. This study introduces a novel ratiometric fluorescence sensor, RhB@Zn-MOF, which was specifically designed for the sensitive and selective detection of L-lactate. Through the strategic incorporation of Rhodamine B (RhB) into Zn-MOF, RhB@Zn-MOF was synthesized, exhibiting dual-emission properties and could effectively distinguish L-lactate in complex biological and food matrices such as milk and sweat based on the competitive absorption mechanism. Notably, the sensor achieves a low detection limit of 0.091 μM and demonstrates excellent stability and reproducibility in varied conditions. Furthermore, the integration of the sensor with smartphone technology enables rapid, real-time analysis, showcasing potential applications in sports medicine, clinical environments, and the food industry.