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Efficient energy transfer is ubiquitous in natural light-harvesting systems (LHSs), which has inspired humans to develop various carrier platforms and energy transfer strategies to mimic nature. In this study, we employ pillar [5]arene-mediated nanoparticles as the nano-platform and a sequential energy transfer strategy to achieve a highly efficient LHS. Specifically, by incorporating the hydrophobic dye, eosin Y (ESY) into the nanoparticles as a relay acceptor, the excitation energy from the host-guest donor WP5 ⸧ G can be efficiently transferred to the final acceptor, sulforhodamine 101 (SR101), making the overall donor energy transfer efficiency up to 94%. Under this condition, the radiative rate constant (k r) of WP5 ⸧ G is almost 8 times higher, and the emission brightness (ε (λ abs) × φ F) is nearly doubled, indicative of the rapid and efficient energy transfer process. Finally, the as-prepared LHS nanoparticles were applied to LED devices to achieve color-tunable photoluminescence. This work demonstrates a fabrication strategy for highly efficient light-harvesting systems that holds great potential for manufacturing bright organic luminescent materials. [Display omitted] • A two-step light-harvesting system was successfully constructed. • The system was completely self-assembled in water phase. • The overall energy transfer efficiency of the donor is up to 94%. • The emission brightness after energy transfer was doubled. • The nanoparticles can be used to make photoluminescent devices. [ABSTRACT FROM AUTHOR]

Sequential energy transfer widely exists in natural light-harvesting systems (LHSs), which greatly benefits the full use of solar energy. In this work, we report an artificial light-harvesting platform derived from pillar (Wang et al., 2021) [5]arene-directed host-guest nanoparticles (WP5 ⊃ G) in aqueous media. The WP5 ⊃ G assembly can serve as a good donor owing to the excellent fluorescence behavior of G in the aggregated state, guaranteeing a two-step FRET from the WP5 ⊃ G to the relay acceptor eosin Y (ESY) and then to the final acceptor Nile red (NiR) to form a WP5 ⊃ G @ ESY / NiR system with high efficiency. As a consequence of the flexibility of the system, tunable emission including a highly efficient white-light emission can be realized. The WP5 ⊃ G @ ESY / NiR system was further used as a photocatalyst to catalyze dehalogenation reaction in aqueous solution, exhibiting remarkable catalytic activity as compared with the WP5 ⊃ G or ESY / NiR alone. [Display omitted] • A light-harvesting system based on self-assembly was successfully fabricated. • The system contains a stepwise energy transfer process. • The material is color tunable and a bright white-light emission was realized. • The material can be used as a photocatalyst for dehalogenation reaction. • The fabrication and application of the system were totally in an aqueous media. [ABSTRACT FROM AUTHOR]

Herein an aqueous-phase artificial light-harvesting platform has been constructed based on the self-assembly of three small organic molecules: a rigid acetal-based spirocyclic skeleton bridged tetraphenylethylene dimer as donor, a hydrophobic dye molecule Nile Red as acceptor, and the surfactant cetyltrimethyl ammonium bromide as amphiphile to enwrap the donor and acceptor and disperse them in water. Due to the rigid skeleton of the tetraphenylethylene dimer that can well accommodate and distribute Nile Red inside the self-assembled nanospheres, the system shows ultrahigh light-harvesting antenna effects. Moreover, by simply tuning the donor/acceptor molar ratio, tunable emission including a bright white-light emission could be realized. Image 1 • An efficient artificial light-harvesting system in water has been constructed by employing small organic molecules. • An ultrahigh antenna effect of 66 could be achieved under a higher donor/acceptor ratio of 250/1. • By simply adjusting the D/A ratio in the NPs, tunable emission including a white-light emission was achieved. • The system is also stable in the solid state and can be used as security inks for anti-counterfeiting techniques. [ABSTRACT FROM AUTHOR]

A novel conjugated polymer (DCT) with intrinsic multifunction was designed and synthesized. High-effect phototheranostic nanoagents DCT NPs were further fabricated based on single-component DCT, which displayed large Stokes shift (363 nm), satisfying near-infrared II (NIR-II) fluorescence emission, good photothermal and photodynamic performances. Under illumination of a single 808 nm laser, high therapeutic efficiency of DCT NPs was confirmed by MTT, live-dead staining and flow cytometry assays. Besides, in vivo high quality NIR-II imaging based on DCT NPs was also demonstrated. Overall, this study provides an effective strategy for constructing of high-effect single-component phototheranostic nanoagents. [Display omitted] • The conjugated polymer DCT could be easily obtained via Stille coupling reaction. • The DCT NPs exhibited outstanding NIR-I absorption, satisfying NIR-II fluorescence emission, and large Stokes shift. • DCT NPs displayed superior biocompatibility, good water-solubility, excellent photostability. • DCT NPs could produce toxic ROS and hyperthermia for elimination of tumor cells under a single 808 laser irradiation. • In vivo vascular structure and tumor imaging was successful executed based on DCT NPs. [ABSTRACT FROM AUTHOR]

A novel oxo-spirocyclic structure bridged ditopic Schiff base fluorescent probe L has been successfully synthesized and characterized. Interestingly, probe L exhibits a specific turn-on response to zinc(II) ion in fluorescence with a high selectivity and sensitivity. Further study show that probe L could be applied in imaging of live cells for sensing zinc(II) ion. By contrast, those compounds ( L1 , L2 , and L3 ) with very similar structure to L lack this properties. The fluorescence intensity of L increases with Zn 2+ , which is less affected by other metal ions. The binding property of L with Zn 2+ was studied by a combination of technologies, such as Job's plot, 1 H NMR, ESI-MS, and DFT calculations. Moreover, we have successfully applied the probe L to detect Zn 2+ in cancer cell. We are anticipating that this new oxo-spirocyclic structure bridged ditopic Schiff base may provide a new idea for the design of fluorescent probe. [ABSTRACT FROM AUTHOR]