Currently, the commonly developed organic luminescent materials (OLMs) usually exhibit poor luminescent performance in aggregated solid states compared with their well-dissolved solution states, making it a tough goal to achieve the highly emissive dual-state emission. To overcome this limitation, a "self-isolated enhanced emission" (SIEE) strategy through flexible alkyl chains to suppress the emission-quenched π-π stacking in solids is proposed here and, based on this guideline, remarkable emission efficiency with photoluminescence quantum yields up to 99.72 % in solution and 77.46 % in the solid state are achieved for the SIEE constructed DBBT-C8, which is then successfully used in solid-state displays and data encryption.

To achieve super-resolution imaging in biological research using stimulated emission depletion (STED) nanoscopy, organic luminescent materials and their corresponding fluorescent nanoparticles with high brightness and photostability are of great significance. Herein, donor-acceptor-typed DBTBT-4C8 bearing flexible alkyl chains was developed, not only to afford deep-red emission from 600 to 800 nm but also to obtain high fluorescent brightness with the absolute photoluminescence quantum yields of 25%. After that, well-defined and monodispersed spherical nanoparticles using DBTBT-4C8 with bright emission, excellent biocompatibility, and photostability, which can easily mix with amphipathic block polymers, were then produced for superresolution in vitro and in vivo imaging using STED nanoscopy. The observations showed that in contrast to confocal microscopy with a full width at half-maximum (FWHM) value of ≈400 nm, superior resolution with a significantly improved FWHM value of only 100 nm was achieved in biomedical cell imaging, which was also used to reconstruct three-dimensional images of stained HeLa cells at an ultrahigh resolution. More importantly, by using the prepared fluorescent organic nanoparticles (FONPs) in STED nanoscopy, in vivo imaging in glass catfish with largely enhanced resolution was also successfully achieved, demonstrating that these developed deep-red FONPs here are highly suitable for superresolution in vitro and in vivo imaging using STED nanoscopy.

Organic nanocrystals (NCs) with high brightness are highly desirable for biological imaging. However, the preparation of NCs in a facile and fast method is still challenging. Herein, aggregation-induced emission (AIE)...

P ancreatic cancer has the number one fatality rate of all cancers, and is the fourth leading cause of cancer related deaths in North America. Overall 5-year survival rate is less than 5%. The risk of developing ductal adenocarcinoma, which constitutes 95% of the pancreas neoplasms, increases with age,

To achieve the highly emissive features and overcome the troublesome photobleaching for fluorescent organic molecules, a facile and versatile strategy named “self-isolation enhanced emission (SIEE)” was developed to prevent the π–π stacking of organic fluorophores by linking alkyl chains on their conjugated backbones. As a proof-of-concept, one or two octyl groups were grafted onto the backbone of 4,7-di­(thiophen-2-yl)­benzo­[c]­[1,2,5]­thiadiazole (termed as DTBT-0), resulting in two different molecules, termed as DTBT-1 and DTBT-2, respectively. Compared with DTBT-0, DTBT-1 and DTBT-2 exhibited remarkably enhanced fluorescent properties in both aggregated thin films and nanoparticles, demonstrating that the SIEE method could isolate the fluorophores effectively and then prevent their π–π stacking to achieve the impressive fluorescent properties. After proper surface modification, excellent water dispersibility, biocompatibility, and improved resistance to photobleaching were also achieved for highly emissive DTBT-2-based nanoparticles, which were then successfully applied for cellular imaging.