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Covalent Organic Framework Functionalized with 8-Hydroxyquinoline as a Dual-Mode Fluorescent and Colorimetric pH
Long Chen1, Linwei He1, Fuyin Ma1
1State Key Laboratory of Radiation Medicine and Protection, School for Radiological and interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions and School of Radiation Medicine and Protection , Soochow University , Suzhou 215123 , China.
ACS Applied Materials & Interfaces
|April 26, 2018
Summary
This study introduces 8-hydroxyquinoline-functionalized covalent organic framework (COF-HQ) for dual-mode pH sensing. This material offers reliable fluorescent and colorimetric detection of acidity in aqueous solutions.
Area of Science:
- Materials Science
- Analytical Chemistry
- Chemical Engineering
Background:
- Accurate pH monitoring is crucial across various scientific and industrial domains.
- Developing robust and reusable pH sensors remains an active area of research.
- Covalent organic frameworks (COFs) offer tunable properties for sensing applications.
Purpose of the Study:
- To develop a novel dual-mode sensor for real-time pH detection.
- To functionalize a covalent organic framework (COF) with 8-hydroxyquinoline (HQ) for enhanced sensing capabilities.
- To evaluate the performance of the COF-HQ material in both fluorescent and colorimetric pH sensing modes.
Main Methods:
- Synthesis of 8-hydroxyquinoline-functionalized covalent organic framework (COF-HQ).
- Investigation of fluorescent emission changes in response to varying pH levels.
- Observation of colorimetric shifts under different acidic conditions.
- Assessment of the reversibility and reusability of the COF-HQ sensor.
Main Results:
- COF-HQ exhibited a decrease in fluorescent emission intensity with decreasing pH (pH 1-5).
- A linear correlation was observed between fluorescence intensity and pH in the acidic range.
- COF-HQ displayed a visible color change from yellow to black as pH decreased.
- The sensor demonstrated reversible responses and could be recycled due to its hydrolytical stability.
Conclusions:
- COF-HQ serves as an effective material for dual-mode (fluorescent and colorimetric) pH sensing.
- The developed sensor offers real-time, accurate, and reusable pH detection in aqueous solutions.
- The material's stability and dual-mode capability make it suitable for practical applications, including integration into mixed matrix membranes.
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