Ling Zang

Introduction to Organic Electronic and Optoelectronic Materials and Devices, Second Edition

Publisher: CRC Press

Date: 03-10-2016

DOI: 10.1201/9781315374185

Diffusion-Controlled Detection of Trinitrotoluene: Interior Nanoporous Structure and Low Highest Occupied Molecular Orbital Level of Building Blocks Enhance Selectivity and Sensitivity

Publisher: American Chemical Society (ACS)

Date: 03-2012

DOI: 10.1021/JA300306E

Abstract: Development of simple, cost-effective, and sensitive fluorescence-based sensors for explosives implies broad applications in homeland security, military operations, and environmental and industrial safety control. However, the reported fluorescence sensory materials (e.g., polymers) usually respond to a class of analytes (e.g., nitroaromatics), rather than a single specific target. Hence, the selective detection of trace amounts of trinitrotoluene (TNT) still remains a big challenge for fluorescence-based sensors. Here we report the selective detection of TNT vapor using the nanoporous fibers fabricated by self-assembly of carbazole-based macrocyclic molecules. The nanoporosity allows for time-dependent diffusion of TNT molecules inside the material, resulting in further fluorescence quenching of the material after removal from the TNT vapor source. Under the same testing conditions, other common nitroaromatic explosives and oxidizing reagents did not demonstrate this postexposure fluorescence quenching rather, a recovery of fluorescence was observed. The postexposure fluorescence quenching as well as the sensitivity is further enhanced by lowering the highest occupied molecular orbital (HOMO) level of the nanofiber building blocks. This in turn reduces the affinity for oxygen, thus allocating more interaction sites for TNT. Our results present a simple and novel way to achieve detection selectivity for TNT by creating nanoporosity and tuning molecular electronic structure, which when combined may be applied to other fluorescence sensor materials for selective detection of vapor analytes.

University Of Utah

Location: United States of America

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Tsinghua University

Location: China

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Shaanxi University Of Science And Technology

Location: China

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Southern Illinois University

Location: United States of America

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China University Of Mining And Technology

Location: China

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Chinese Academy Of Science

Location: China

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Southern Illinois University

Location: No location found

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