Multimodal Fluorescent Polymer Sensor for Highly Sensitive Detection of Nitroaromatics

Area of Science:

• Polymer Chemistry
• Materials Science
• Analytical Chemistry

Background:

• Sensitive and selective detection of nitroaromatic explosives is crucial for safety.
• Existing methods for explosive detection face limitations in sensitivity, selectivity, or cost.

Purpose of the Study:

• To synthesize and characterize a novel emissive copolymer for multimodal sensing of nitroaromatic explosives.
• To evaluate the copolymer's performance in detecting explosives in both solution and vapor phases.

Main Methods:

• RAFT copolymerization was used to synthesize the P(MMA-co-Dansyl-Ala-HEMA) (DCP) copolymer.
• Fluorescence spectroscopy (including up-conversion and time-resolved) was employed to assess sensing capabilities.
• Density Functional Theory (DFT) studies were conducted to understand the sensing mechanism energetics.
• A thin film polymer sensor was fabricated and tested for vapor detection.

Main Results:

• The DCP copolymer demonstrated high sensitivity and selectivity for nitroaromatic explosives (DNT, TNT, TNP) at µM levels in solution and with saturated vapors.
• The copolymer exhibits a high quantum yield (Φf = 77%), suitable for both solution and vapor phase sensing.
• Fluorescence quenching was observed upon explosive addition, with a high Stern-Volmer constant, indicating efficient detection.
• The fabricated thin film sensor successfully detected nitroaromatic vapors with high selectivity.

Conclusions:

• The synthesized DCP copolymer is a promising candidate for sensitive and selective detection of nitroaromatic explosives.
• The multimodal sensing capability (solution and vapor) and potential for low-cost fabrication open avenues for practical explosive detection devices.
• This research contributes to enhanced safety through advanced materials for explosive detection.