A dual-emission pyrene-based new
fluorescent probe (
N
-(4-nitro-phenyl)-
N
′-pyren-1-ylmethyl-ene-ethane-1,2-diamine
(PyDA-NP)) displays green fluorescence for nitric oxide (NO) sensing,
whereas it exhibits blue emission in the aggregated state. The mechanism
of nitric oxide (NO/NO
+
) sensing is based on N-nitrosation
of aromatic secondary amine, which was not interfered by reactive
oxygen species and reactive nitrogen species. The aggregation-induced
enhancement of emission (AIEE) behaviors of the PyDA-NP could be attributed
to the restriction of intramolecular rotation and vibration, resulting
in rigidity enhancement of the molecules. The AIEE behavior of the
probe was well established from fluorescence, dynamic light scattering,
scanning electron microscopy, transmission electron microscopy, X-ray
diffraction, optical fluorescence microscopy, and time-resolved photoluminescence
studies. In a H
2
O/CH
3
CN binary mixture (8:2
v/v), the probe showed maximum aggregation with extensive (833-fold)
increases in fluorescence intensity and high quantum yield (0.79).
The aggregated state of the probe was further applied for the detection
of nitroexplosives. It displayed efficient sensing of 2,4,6-trinitrophenol
(TNP), corroborating mainly the charge-transfer process from pyrene
to a highly electron-deficient TNP moiety. Furthermore, for the on-site
practical application of the proposed analytical system, a contact-mode
analysis was performed.