Dual-Channel Luminescent Signal Readout Strategy for Classifying Aprotic/Protic Polar Organic Medium and Naked-Eye Monitoring of Water in Organic Solvents

• Published in: Analytical chemistry (Washington) Vol. 92; no. 13; pp. 8974 - 8982
• Main Authors: Li, Jinfang, Du, Peiyao, Chen, Jing, Huo, Shuhui, Han, Zhengang, Deng, Yang, Chen, Yang, Lu, Xiaoquan
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 07.07.2020
• Subjects: Chemical industry; Chemistry; Colorimetry; Environmental monitoring; Fluorescence; Fluorescent dyes; Fluorescent indicators; Hydrogen bonding; Intelligence; Light emission; Logic circuits; Metal-organic frameworks; Moisture content; Organic solvents; Rhodamine 6G; Ships; Signal classification; Solvents; Water content
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.0c00966

Developing a convenient and rapid detection method for water is greatly desirable in the field of chemical industry. Herein, we present a simple and effective strategy combining a fluorescence sensor and a one-to-two fluorescence colorimetric logic operation to monitor water in a wide range of organic media and classify aprotic/protic polar solvents. The dual-emitting luminescent detector was prepared by incorporating a fluorescent dye Rhodamine 6G (R6G) with strong green light emission within a red light-emitting Eu-metal–organic framework (MOF) through the “bottle around ship” method. R6G@Eu-MOF displays completely different fluorescence response behaviors to various organic solvents. Thus, when one made use of the intensity ratio of different fluorescence emission centers, a 3D decoded map was proposed to reliably and effectively distinguish different aprotic/protic polar solvents. Moreover, R6G@Eu-MOF exhibited two different ratiometric sensing modes when detecting water in aprotic/protic polar solvents due to the hydrogen bonding interaction, that is ratiometry with one reference signal or two reversible signal changes. Furthermore, using water content as the input signal and two kinds of fluorescence emission as the output signals, a one-to-two logic gate system was constructed, making it possible to develop an intelligence system for water detection. Overall, we demonstrated for the first time that R6G@Eu-MOF could serve as an efficient platform for tracing water in organic media and distinguishing protic/aprotic polar organic solvents.