Double-Color Lanthanide Metal–Organic Framework Based Logic Device and Visual Ratiometric Fluorescence Water Microsensor for Solid Pharmaceuticals

Abstract

Water is one of the most widespread impurities and contaminants for pharmaceuticals and chemical products. A simple, fast and reliable water assay method is of high significance for the pharmaceutical and chemical manufacturing industries. In this work, lanthanide metal–organic framework Eu-dipicolinic acid/2-aminophthalic acid (Eu-DPA/PTA-NH2) was prepared as a double-color ratiometric fluorescent water sensor, which shows ultrasensitive (limit of detection 0.01% v/v) and linear broad-range (0–100% v/v) response to water. An innovative analytical device based on a one-to-two logic gate was constructed by using the water content and the two fluorescence responses as the input and output signals, respectively. The direct analysis of water content can be achieved by the four output types, NOT (0, 1), PASS 0 (0, 0), PASS 1 (1, 1), and YES (1, 0). Importantly, the metal–organic framework (MOF)-loaded fiber paper was prepared as a microsensor, and a water assay tube was designed for rapid water detection of solid pharmaceuticals via ratiometric chromaticity, coupled with a portable visual determination device. The paper-based microsensor is response-rapid (20 s), long-term stable (at least 30 days), and can achieve the accurate (relative error <9.8%) visual assay of trace water in solid pharmaceuticals. To our knowledge, this is the first time to report an MOF-based double-color ratiometric fluorescent water sensor, a water analytical logic device, and a paper-based water microsensor for point-of-care visual water assay in solid samples via ratiometric chromaticity.

Water-sensitive multicolor luminescence in lanthanide-organic framework for anti-counterfeiting

“…Among these reasons, the quenching of Ln 3+ emission caused by O-H oscillators is the dominant one. This is because BDC-NH 2 possesses hydrophilic active sites −NH 2 , thus water molecules enter cages easily, and meanwhile, the introduction of water results in the increase of nonradiative decay pathways (O-H oscillators) that prevents radiative relaxation (emission), accounting for the quenching of Ln 3+ emission 34,35 . On the other hand, we speculate that there may be another mechanism.…”

Recent Advances in Developing Lanthanide Metal–Organic Frameworks for Ratiometric Fluorescent Sensing

“…In particular scenarios, changes in output emission color can be observed, allowing for fast visual screening of analytes. The modulation of antenna effect to quench the lanthanide luminescence is probably the most commonly employed sensing approach by LnMOFs (Cui et al, 2019;Moscoso et al, 2020;Yu et al, 2020). For example, Yu et al (2020) developed a trace water sensor based on Eu-MOF with the mixed ligand of dipicolinic acid (DPA) and 2-aminophthalic acid (PTA-NH 2 ).…”

“…Analyte interacts with the sensor by suppressing (A-C) or enhancing (D-F) the antenna effect. Reproduced fromYu et al (2020) with permission from American Chemical Society andZhang et al (2018) with permission from The Royal Society of Chemistry. The analyte may also change the coordination environment of Ln (G,H) or modulate the lanthanide-lanthanide energy transfer (I,J).…”

Ultrafast scale-up synthesis of calcium rod/layer MOFs and luminescence detection of water in organic solvents

“…For a polar molecule such as 2-aminoterephthalic acid, the stabilization effect is decreased while the ground-state and excited-state energy levels are elevated and thus the luminescence intensity is lowered. 40 At the same time, an increase in the polarity of the solvent makes the fluorescent emission peak of the organic ligand with amino groups shift toward a longer wavelength. 41 In order to confirm this speculation, the dependence of emission energy with the moisture content is correlated with the dielectric constants of the mixed solvents (Fig.…”