Robust lanthanide MOFs as multifunctional luminescent sensors for intelligent visualization monitoring of MEAA and texture code anti-counterfeiting applications

Abstract

2-(2-Methoxyethoxy)ethanol (MEEA) can cause DNA damage and teratogenesis, and the biomarker of MEEA is 2-(2-methoxyethoxy)acetic acid (MEAA). Therefore, portable and accurate monitoring of MEAA has far-reaching significance to ensure human health. In this work, a series of isometric three-dimensional (3D) lanthanide metal–organic frameworks (Ln-MOFs) {[Ln_0.5(L)(H₂O)]·1.5H₂O}_n (1-Ln, Ln = Eu, Tb, Eu_xTb_1−x) were synthesized by using 1-(4-carboxyphenyl)-1H-pyrazole-4 carboxylic acid (H₂L) and Ln³⁺. 1-Eu showed excellent sensing performance for MEAA with ultra-low detection limit (0.39 μM) and fast response time (within 1 min). To enhance the practicability of 1-Eu, three visual detection strategies of MEAA were provided. The polytetrafluoroethylene (PTFE) fluorescence film (Film@1-Eu) had a detection limit as low as the ppm level, and the fluorescence test paper achieved quantitative MEAA detection by combining with a smartphone sensing platform. In addition, a portable intelligent logic detector based on 1-Eu was designed by introducing a logic gate strategy for the real-time detection of MEAA. Notably, a Ln-MOF texture code with a high encryption algorithm and information density was designed for anti-counterfeiting labels on merchandise, utilizing the distinctive tuneable emission characteristic of 1-Ln. This study not only achieved the first visual detection of MEEA but also provided novel insights for the design of anti-counterfeiting materials.