Smartphone-assisted fluorescent sensor for the visualization and quantitative detection of doxycycline and L-arginine.

A novel smartphone-assisted fluorescent sensor based on europium/zirconium metal-organic framework (Eu _0.5 /Zr _0.5 -MOF) was developed for the fast and sensitive determination of doxycycline (DOX) and L-arginine (Arg). After the addition of DOX, the fluorescence of Eu _0.5 /Zr _0.5 -MOF was quenched owing to the inner filter effect (IFE). When Arg was introduced into the Eu _0.5 /Zr _0.5 -MOF@DOX complex system, the fluorescence was recovered because the interaction between Arg and Eu _0.5 /Zr _0.5 -MOF@DOX weakened the IFE. Moreover, the Eu _0.5 /Zr _0.5 -MOF produced continuous fluorescence color changes for the visual measurement of DOX and Arg. The fluorescent probe for DOX and Arg offered broad linear ranges of 0.05-80 and 0.1-60 μg/mL, respectively, with detection limits as low as 2.07 and 67.5 ng/mL. The proposed method was successfully applied to monitor DOX in eggs and Arg in human serum. This work provides a powerful platform for the real-time and visual analysis of DOX and Arg in food and biological samples.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier Ltd. All rights reserved.)