Tetraphenylethene‐Based Conjugated Fluoranthene: A Potential Fluorescent Probe for Detection of Nitroaromatic Compounds

Abstract

This study reports the synthesis and photophysical properties of a star-shaped, novel, fluoranthene-tetraphenylethene (TFPE) conjugated luminogen, which exhibits aggregation-induced blue-shifted emission (AIBSE). The bulky fluoranthene units at the periphery prevent intramolecular rotation (IMR) of phenyl rings and induces a blueshift with enhanced emission. The AIBSE phenomenon was investigated by solvatochromic and temperature-dependent emission studies. Nanoaggregates of TFPE, formed by varying the water/THF ratio, were investigated by SEM and TEM and correlated with optical properties. The TFPE conjugate was found to be a promising fluorescent probe towards the detection of nitroaromatic compounds (NACs), especially for 2,4,6-trinitrophenol (PA) with high sensitivity and a high Stern-Volmer quenching constant. The study reveals that nanoaggregates of TFPE formed at 30 and 70% water in THF showed unprecedented sensitivity with detection limits of 0.8 and 0.5 ppb, respectively. The nanoaggregates formed at water fractions of 30 and 70% exhibit high Stern-Volmer constants (Ksv=79,998 and 51,120 M(-1), respectively) towards PA. Fluorescence quenching is ascribed to photoinduced electron transfer between TFPE and NACs with a static quenching mechanism. Test strips coated with TFPE luminogen demonstrate fast and ultra-low-level detection of PA for real-time field analysis.

Studies on Fluorescence Quenching of DBSA‐PANI‐Employing Nitroaromatics.

“…The electrons come back to ground state with the non radiative process resulting in marked decrease fluorescent intensity of conjugated polymer indicating a possibility of energy transfer from the energy donor PANI host to the energy acceptor PA‐a guest. With the increase in the number of electron deficient –NO 2 groups, electron transfer from the polymer to the analyte becomes thermodynamically more feasible …”

Electrospun fluorescent nanofibrous membranes for trace explosive detection

“…物的检测产生干扰, 而AIE材料特有的发光特性可有 效避免该干扰, 从而提升爆炸物检测的灵敏度 [8,44,87,88] . AIE材料具有低背景 [89,90] 、信噪比高 [44] 、灵敏度 好 [45,93,94] 和纳米团簇 [95,96] .…”

Dual-Targeted Gold Nanoprism for Recognition of Early Apoptosis, Dual-Model Imaging and Precise Cancer Photothermal Therapy

“…Multifunctional nano-composites have been well developed and attracted significant attention due to their unique structures and excellent performance 25, 26. Conventional photosensitizers may be quenched by aggregation, and design of materials with aggregation-induced emission (AIE) characteristics has become the research focus 27, 28. Tetraphenylethene (TPE) as a conjugated helical molecule shows highly emissive in the aggregate state, where the restriction of the intramolecular rotation of the phenyl substituent can be inhibited by non-radiative decay pathways 28-31.…”