An AIE-Active Ultrathin Polymeric Self-Assembled Monolayer Sensor for Trace Volatile Explosive Detection.

Area of Science:

• Materials Science
• Analytical Chemistry
• Chemical Engineering

Background:

• Trace detection of volatile nitroaromatic compound (NAC) explosives is crucial for security.
• Existing detection methods often lack sensitivity, stability, or ease of use.
• Polymeric self-assembled monolayers (SAMs) offer potential for enhanced sensor performance.

Purpose of the Study:

• To develop novel polymeric SAM sensors for sensitive and selective detection of NAC explosives.
• To leverage aggregation-induced emission (AIE) luminogens for enhanced fluorescence quenching.
• To create cost-effective and user-friendly explosive detection platforms.

Main Methods:

• Polymerization of 1,1,2,2-tetraphenylethene (TPE) into PTPE, an AIE luminogen.
• Formation of SAMs on Al2O3 substrates using phosphoric acid as an anchor group.
• Fabrication of sensors on silicon wafers and inorganic testing paper.
• Detection of NAC explosives via fluorescence quenching.

Main Results:

• Polymeric SAM sensors demonstrated good response speed, reversibility, selectivity, and sensitivity.
• Detection limits achieved were as low as 0.07 ppm for TNT, 0.35 ppm for DNB, and 4.11 ppm for NB on testing paper.
• The paper-based sensors exhibited high fluorescence intensity, enabling naked-eye detection under UV light.

Conclusions:

• Polymeric SAMs incorporating AIE luminogens are effective for trace NAC explosive detection.
• The developed sensors offer a promising foundation for developing inexpensive and portable explosive detection devices.
• The naked-eye detection capability of the paper-based sensors highlights their practical application potential.