A nanoscopic supramolecular aggregate is constructed from perylene bisimide‐bridged bis‐(permethyl‐β‐cyclodextrins) 1 via π–π stacking interactions. Its self‐assembly behavior in organic and aqueous solutions is investigated by UV–Vis, fluorescence, and 1H NMR spectroscopy. Transmission electron microscopy and scanning electron microscopy images show the 1D nanorod aggregation of 1, which is birefringent under crossed polarizer conditions and strongly fluorescent as depicted in the fluorescence microscopy image. X‐ray powder diffraction measurements indicate that 1 forms a well‐ordered crystalline arrangement with a π–π stacking distance of 4.02 Å. Furthermore, the solid‐state fluorescence sensing is explored by utilizing the poly(vinylidene fluoride) membrane‐embedded 1, giving that 1, as a novel vapor detecting material, can probe several kinds of volatile organic compounds and, especially, exhibits high sensitivity to organic amines.

Self-assembled fluorescent nanoparticles responding to specific stimuli are highly appealing for applications such as labels, probes, memory devices, and logic gates. However, organic analogues are challenging to prepare, due to unfavorable aggregation-caused quenching. We herein report the preparation of self-assembled fluorescent organic nanoparticles in water by means of calixarene-induced aggregation of a tetraphenylethene derivative (QA-TPE) mediated by p-sulfonatocalix[4]arenes. The self-assembled nanoparticles showed interesting photoswitching behaviors, and the fluorescence output of the generated nanoparticles was opposite to that of free QA-TPE both before and after irradiation. Free QA-TPE is nonfluorescent, owing to intramolecular rotations of the phenyl rings. In contrast, the self-assembled nanoparticles that formed upon complexation of QA-TPE with p-sulfonatocalix[4]arene exhibited aggregation-induced emission fluorescence (λ(em) = 480 nm, Φ = 14%), as a result of the inhibition of rotations. Upon UV light irradiation, free QA-TPE was cyclized to the corresponding diphenylphenanthrene, which showed typical fluorescence of a π-conjugated system (λ(em) = 385 nm, Φ = 9.3%), whereas the nanoparticles were nonfluorescent upon irradiation due to the aggregation-caused quenching. In effect, this system allows programmed modulation of TPE fluorescence at two different emission wavelengths by means of host-guest complexation and irradiation. Relative to a single-mode stimulus-responsive system, our new developed system of highly integrated modes into a single molecular unit that can exhibit modulation of fluorescence by multiple stimulus is expected to be more adaptable for practical applications and to show enhanced multifunctionality.

Water-soluble hyaluronic acid–hybridized polyaniline nanoparticles show effective photothermal ablation of cancer with targeted specificity.

An asymmetric, amphiphilic perylene bisimide derivative 1 was synthesized by grafting permethyl-β-cyclodextrin at one side and an octadecyl chain at the other side. Its aggregation capability and morphology, which attract intense interest, were carefully examined by combination of UV-vis, NMR, and fluorescence spectroscopy, DLS, XRD, TEM, and SEM. By adjusting the volume ratio of water and methanol, we are able to control the morphology, benefiting from the amphiphilicity of 1. Furthermore, the particular resulting aggregates were employed as solid-state fluorescence sensing for organic amines. An improvement of both selectivity and sensitivity is achieved compared to previous publications.

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