Rare-earth-doped fluoride nanoparticles with engineered long luminescence lifetime for time-gated: In vivo optical imaging in the second biological window

Biomedicine is continuously demanding new luminescent materials to be used as optical probes for the acquisition of high resolution, high contrast and high penetration in vivo images. These materials, in combination with advanced techniques, could constitute the first step towards new diagnosis and therapy tools. In this work, we report on the synthesis of long lifetime rare-earth-doped fluoride nanoparticles by adopting different strategies: core/shell and dopant engineering. The here developed nanoparticles show intense infrared emission in the second biological window with a long luminescence lifetime close to 1 millisecond. These two properties make the here presented nanoparticles excellent candidates for time-gated infrared optical bioimaging. Indeed, their potential application as optical imaging contrast agents for autofluorescence-free in vivo small animal imaging has been demonstrated, allowing high contrast real-time tracking of gastrointestinal absorption of nanoparticles and transcranial imaging of intracerebrally injected nanoparticles in the murine brainThis work was supported in part by the grants from the Fundamental Research Funds for the Central Universities, China (HIT. BRETIV.201503 and AUGA5710052614) and the National Natural Science Foundation of China (51672061). We thank Dr Lina Wu at the Fourth Hospital of Harbin Medical University for her kind help with the MTT assay, and Dr Tymish Y. Ohulchanskyy at Shenzhen University for his kind help with the fluorescence lifetime measurement. The work was also supported by the Ministerio de Economia y Competitividad of Spain (grant MAT2016-75362-C3-1-R). Jie Hu acknowledges the scholarship from the China Scholarship Council (No. 201506650003). Dirk H. Ortgies is grateful to the Spanish Ministry of Economy and Competitiveness for a Juan de la Cierva scholarship (No. FJCI-2014-21101) and the Spanish Institute of Health (ISCIII) for a Sara Borell Fellowship (No. CD17/00210

A hybrid molecular sensitizer for triplet fusion upconversion

Triplet fusion upconversion is useful for a broad spectrum of applications ranging from solar cells, photoredox catalysis, to biophotonics applications, especially in the near-infrared (NIR,>700 nm) range. This upconverting system typically demands efficient conversion of spin-singlet harvested energy through intersystem crossing to spin-triplet states, accessible only in rare metallic-coordinating macrocycle compounds or heavy-metal-containing semiconductor quantum dots for triplet sensitization. Herein, we describe an organic–inorganic system for NIR-to-visible triplet fusion upconversion, interfacing commonly-seen, non-metallic, infrared dyes (IR806, IR780, indyocynine green, and CarCl) and lanthanide nanocrystal (sodium ytterbium fluoride) as a hybrid molecular sensitizer, which extracts molecular spin-singlet energy to nanocrystal-enriched ytterbium dopants at ~48% efficiency (IR806, photoexciation at 808 nm). Moreover, ytterbium sub-lattice energy migration increases the interaction possibility between the nanocrystal and the freely-diffusing rubrenes in solution, resulting in 24-fold (IR806) to 1740-fold (indocyanine green) upconversion (600 nm) increase, depending on the IR dye type, as compared to the one without ytterbium nanotransducers. Ab initio quantum chemistry calculations identify enhanced spin-orbital coupling in the ytterbium-IR806 complex and high energy transfer rate in the ytterbium-rubrene interaction (1010 s 1). Employing inorganic lanthanide nanocrystals as nanotransducers unleashes the potential use of non-metallic infrared organic dyes for triplet fusion upconversion

Evaluation of protein extraction methodologies on bacterial proteomic profiling: a comparative analysis

Bacterial proteomics is a pivotal tool for elucidating microbial physiology and pathogenicity. The efficiency and reliability of proteomic analyses are highly dependent on the protein extraction methodology, which directly influences the detectable proteome. In this study, we systematically compared four protein extraction protocols—SDT lysis buffer with boiling (SDT-B), SDT lysis buffer with ultrasonication (SDT-U/S), a combination of boiling and ultrasonication (SDT-B-U/S), and SDT lysis buffer with liquid nitrogen grinding followed by ultrasonication (SDT-LNG-U/S)—to evaluate their effects on peptide and protein identification, distribution, and reproducibility in Escherichia coli and Staphylococcus aureus. Both data-dependent acquisition (DDA) and data-independent acquisition (DIA) strategies were employed for comprehensive proteomic profiling. DDA analysis identified 23,912 unique peptides corresponding to 2,141 proteins in E. coli and 13,150 unique peptides corresponding to 1,511 proteins in S. aureus. DIA analysis yielded slightly fewer peptides (21,027 for E. coli and 7,707 for S. aureus) but demonstrated superior reproducibility. Among the tested protocols, SDT-B-U/S outperformed the others, identifying 16,560 peptides for E. coli and 10,575 peptides for S. aureus in DDA mode. It also exhibited the highest technical replicate correlation in DIA analysis (R2 = 0.92). This method enhanced the extraction of proteins within key molecular weight ranges (20–30 kDa for E. coli; 10–40 kDa for S. aureus) and was particularly effective for recovering membrane proteins (e.g., OmpC). Additionally, ultrasonication-based protocols outperformed the liquid nitrogen grinding approach in extracting the S. aureus proteome. These findings underscore the significant impact of protein extraction methods on bacterial proteomics. The SDT-B-U/S protocol—thermal denaturation followed by ultrasonication—proved most effective, enhancing protein recovery and reproducibility across both Gram-negative and Gram-positive bacteria. This work offers key guidance for optimizing microbial proteomic workflows

Effect of SiO2 nanoparticles on the hydrophobic properties of waterborne fluorine-containing epoxy coatings

A nano-composite coating was developed by adding nano-SiO2 to a home-made Waterborne fluorine-containing epoxy resin. The surface hydrophlicity of the coating was investigated by the contact angle with water. As the particle sizes of SiO2 changed from 7-18nm, the water contact angle of the films changed from 62.8° to 85.6°. The surface energy of the coating was calculated out through measuring the contact angles of the coating with water and 1-bromonaphthalene. The presence of SiO2 significantly enhanced the corrosion resistance of the composite coatings, which showed two times than that of the neat waterborne fluorine-containing epoxy coatings. And the thermos dynamic stability of the composite coatings has been significantly improved. When the silica content is 2.0%, the coating has the largest contact angle. Other performance of the coating was investigated in terms of their thickness, flexibility, pencil hardness, impact resistance