Enhancing Dye-Triplet-Sensitized Upconversion Emission Through the Heavy-Atom Effect in CsLu2 F7 :Yb/Er Nanoprobes.

Lanthanide (Ln3+ )-doped upconversion (UC) nanoprobes, which have drawn extensive attention for various bioapplications, usually suffer from small absorption cross-sections and weak luminescence intensity of Ln3+ ions. Herein, we report the controlled synthesis of a new class of Ln3+ -doped UC nanoprobes based on CsLu2 F7 :Yb/Er nanocrystals (NCs), which can effectively increase the intersystem crossing (ISC) efficiency from singlet excited state to triplet excited state of IR808 up to 99.3 % through the heavy atom effect. By virtue of the efficient triplet sensitization of IR808, the optimal UC luminescence (UCL) intensity of IR808-modified CsLu2 F7 :Yb/Er NCs is enhanced by 1309 times upon excitation at 808 nm. Benefiting from the intense dye-triplet-sensitized UCL, the nanoprobes are demonstrated for sensitive assay of extracellular and intracellular hypochlorite with an 808-nm/980-nm dual excited ratiometric strategy.

Highly efficient NIR-II luminescent I-III-VI semiconductor nanoprobes based on AgInTe2:Zn/ZnS nanocrystals.

Highly efficient luminescence of AgInTe2:Zn/ZnS nanocrystals with the maximum NIR-II quantum yield of 25.2% has been designed through elaborately manipulating the structure to reduce their internal and surface defects. These AgInTe2:Zn/ZnS nanoprobes were employed for sensitive homogeneous biodetection of xanthine oxidase with the limit of detection down to 25 nU L-1.

Rapid and accurate detection of phosphate in complex biological fluids based on highly improved antenna sensitization of lanthanide luminescence.

Rapid and accurate detection of phosphate (Pi) in complex biological fluid is of critical importance for timely warning of Pi accumulation and monitoring Pi related pathological process. Up to date, various luminescent probes have been developed for Pi determination in aqueous media. However, the huge obstacles of the current probes suffer from the inherent issues such as time-consuming, tedious preparation and unavoidable background interference during Pi detection. To circumvent this limitation, we proposed a universal and facile strategy to fabricate a novel sensitizer-Ln3+@surfactant micelle probe with time-resolved luminescent (TRL) superiority through the self-assembly of sensitizer, Ln3+ and surfactant. Through this design, the sensitizer-Ln3+ chelate can be encapsulated into the surfactant constructed micelle and Ln3+ luminescence can be substantially lighted up through the effective energy transfer from the coordinated sensitizer and the assistance of Triton X-100. Such high TRL signal can be sensitively and specifically quenched by Pi, which was attributed to the specific coordination competition between sensitizer and Pi towards Ln3+. Benefitting from the background-free interference and highly sensitive TRL response of the sensitizer-Ln3+@surfactant probe, we achieved the rapid, selective and sensitive detection of Pi in the range of 0.5-120 µM with a limit of detection (LOD) of 0.19 µM. Furthermore, the accuracy of the proposed method based on the Ln3+ involved micelle probes was further verified through the quantitation of Pi in real biological samples.