Although organic light-emitting molecules have received a growing attention and applicability in modern bioimaging science, the design and control of complex photoluminescent properties in unimolecularly selective imaging remains a challenging topic. Considering that tunable multipathway imaging can be advantagedly connected with treatment processes in therapy, the integration of an azulene and a cyanostyryl moiety into one skeleton is carried out for the generation of in situ stimuli-responsive luminescent materials, with the aim to achieve tunable and effective emissions in distinct channels through smart molecular design on a single-molecular platform. This strategy takes advantage of 1) the Z/E isomerization of the cyanostyryl unit that can vary the push-pull effect of the substitution on azulene, accompanied by altering absorption and emission of individual excited states, and 2) an optimized excited-state regulation for opening a near infrared emissive channel and making up for a controllable dual-pathway luminescent system together with the utilization of visible emission. As exemplified by a demonstration of manipulating the luminescence at the cell level, the materials exhibit a superior application potential for unimolecularly selective imaging, labeling and probing events.

Here we have demonstrated a facile method for construction of self-assembled nanoparticles with excellent fluorescent properties by the synergetic combination of unique AIE effects and tadpole-shaped polymers. The introduction of acid-sensitive Schiff base bonds furnished the polymeric vesicles and micelles with unique pH responsiveness that can possess maximal drug-release controllability inside tumor cells upon changes in physical and chemical environments, but present good stability under physiological conditions. Having benefited from the efficient fluorescence resonance energy transfer (FRET), the DOX-loaded fluorescent aggregates were employed for intracellular imaging and self-localization in surveillance of systemic DOX delivery. Cytotoxicity assay of the DOX-loaded aggregates indicated a fast internalization and a high cellular proliferation inhibition to MCF-7 cells while the PEG-POSS-(TPE)7 nanoparticles displayed no cytotoxicity, exhibiting excellent biocompatibility and biological imaging properties. These results indicated that these biodegradable nanoparticles, as a class of effective pH-responsive and visible nanocarriers, have the potential to improve smart drug delivery and enhance the antitumor efficacy for biomedical applications.