Highly sensitive gas-phase explosive detection by luminescent microporous polymer networks

Area of Science:

• Materials Science
• Analytical Chemistry
• Polymer Science

Background:

• Microporous networks (MPNs) offer high surface areas for sensing applications.
• Spiro-carbazole based polymers (PSpCz) exhibit luminescence properties suitable for detection.
• Nitro-aromatic compounds are common explosives requiring sensitive detection methods.

Purpose of the Study:

• To develop and evaluate PSpCz-based MPNs as luminescent sensors for nitro-aromatic compounds.
• To investigate the effect of microporosity on sensor performance.
• To demonstrate sensitive detection of trace explosives.

Main Methods:

• Electrochemical deposition of PSpCz to form MPNs on various substrates.
• Characterization of MPN specific surface area (1300 m²/g).
• Luminescence quenching studies upon exposure to nitro-aromatic analytes (nitrobenzene, 2,4-DNT, TNT).

Main Results:

• PSpCz MPNs exhibit selective luminescence quenching by nitro-aromatic compounds.
• MPNs show significantly enhanced sensitivity compared to non-porous spiro-carbazole.
• Detection of TNT at concentrations as low as 5 ppb was achieved, far exceeding the performance of control samples.

Conclusions:

• PSpCz-based MPNs are highly effective luminescent sensors for nitro-aromatic compounds.
• The microporous structure significantly enhances sensitivity for trace explosive detection.
• Electrochemical deposition provides a low-cost, scalable method for fabricating these advanced sensors.