A porous β-cyclodextrin-based terpolymer fluorescence sensor for in situ trinitrophenol detection

Area of Science:

• Materials Science
• Polymer Chemistry
• Analytical Chemistry

Background:

• Permanent porosity is crucial for fluorescent polymers exhibiting
• "on-off" emissive properties, enabling guest adsorption at fluorophore sites.
• Nitroaromatic compounds are common environmental pollutants requiring sensitive detection methods.

Purpose of the Study:

• To design and synthesize a novel porous fluorescent polymer (FL-PFP).
• To investigate the gas uptake properties and textural characteristics of FL-PFP.
• To evaluate the potential of FL-PFP for the detection of nitroaromatic compounds.

Main Methods:

• Covalent cross-linking of β-cyclodextrin (β-CD), 4,4'-diisocyanato-3,3'-dimethyl biphenyl (DL), and tetrakis(4-hydoxyphenyl)ethene (TPE) to form FL-PFP.
• Gas uptake measurements (N₂ and CO₂) to determine BET surface area.
• Fluorescence spectroscopy to monitor the quenching effect of nitroarenes (trinitrophenol and nitrobenzene) on FL-PFP.

Main Results:

• FL-PFP exhibited a BET surface area of 100-150 m² g^-1 (N₂) and 20-30 m² g^-1 (CO₂).
• Nitroarenes (TNP and NB) induced significant fluorescence quenching (up to 50%) at low concentrations (~50 nM).
• Strong donor-acceptor interactions between nitroarenes and the TPE unit were responsible for fluorescence quenching.

Conclusions:

• The synthesized β-CD terpolymer (FL-PFP) demonstrates effective porous characteristics.
• FL-PFP shows high sensitivity and rapid response for detecting nitroarenes.
• This polymer holds significant potential for monitoring nitroarenes in aquatic environments and complex media.