Highly Efficient Near-Infrared II Electrochemiluminescence from NaYbF4 Core Mesoporous Silica Shell Nanoparticles

Due to less interference in biological imaging, nano -materials with second near-infrared (NIR-II) window (950-1700 nm) emission have received tremendous attention. However, no reports on NIR-II electro-chemiluminescence (ECL) imaging exist because of the lack of high-efficiency NIR-II ECL luminophores. Herein, we designed and synthesized a NaYbF4@SiO2 core-shell nanoparticle for the first time, which exhib-ited a record-high ECL efficiency of 384% relative to the benchmark Ru(bpy)(3)(2+). The NaYbF4 core ensured a maximum emission peak at 983 nm; the synergistic effect of enrichment and catalysis provided by an external mesoporous shell significantly enhanced the ECL signal of particles and improved the stab-ility. Moreover, the ECL generation mechanism was identified through density functional theory calculations. This work has broken through the wavelength bottleneck of NIR-ECL probes in the water-phase and can guide the design of subsequent NIR-II ECL emitters. [GRAPHICS] .