Sensitive Detection of Trace Explosives by a Self-Assembled Monolayer Sensor.

Area of Science:

• Materials Science
• Analytical Chemistry
• Chemical Engineering

Background:

• Fluorescence probe technology offers high sensitivity and selectivity for trace explosive detection.
• Aggregation-induced emission (AIE) is a valuable property for developing sensitive optical sensors.
• Nitroaromatic compounds (NACs) are common and hazardous explosives requiring reliable detection methods.

Purpose of the Study:

• To develop a novel self-assembled monolayer (SAM) based fluorescence probe for trace NAC detection.
• To utilize the aggregation-induced emission (AIE) property of 1,1,2,2-tetraphenylethene (TPE) for enhanced sensing.
• To investigate the role of a phosphoric acid anchoring unit in the TPE-PA-8 molecule for improved sensing performance.

Main Methods:

• Synthesis of the TPE-PA-8 molecule incorporating TPE and a phosphoric acid anchoring unit.
• Fabrication of SAMs on Al2O3-deposited fiber film.
• Evaluation of the SAMs' detection performance for various NAC explosives using fluorescence spectroscopy.

Main Results:

• The TPE-PA-8 molecule exhibited enhanced light-emission properties due to promoted aggregation.
• SAMs demonstrated remarkable detection limits for trinitrotoluene (0.68 ppm), dinitrotoluene (1.68 ppm), and nitrobenzene (2.5 ppm).
• The phosphoric acid anchoring unit was crucial for promoting TPE aggregation and improving sensing capabilities.

Conclusions:

• The developed SAMs offer a high-performance, user-friendly platform for trace NAC detection.
• This work presents a viable candidate for flexible sensors with excellent explosive detection capabilities.
• The designed TPE-PA-8 molecule and SAMs pave the way for advanced fluorescence-based explosive sensing technologies.