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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.