Unlocking NIR-II Photoluminescence in 2D Copper Tetrasilicate Nanosheets through Flame Spray Synthesis
RESOLV Member, Prof. Sebastian Kruss and his research team discover a novel synthesis strategy, thereby unlocking wavelength-tunable Nanosheets for advanced NIR-II Bioimaging.
In this study, the authors introduce a flame-spray-pyrolysis strategy to synthesize ultra-bright, metastable copper tetrasilicate (CTS) nanosheets tailored for second near-infrared (NIR-II) bioimaging. By annealing multicomponent oxide nanoparticles into 2D CTS crystals and tuning Group-II ion incorporation, they achieve wavelength-selective emission extending into the NIR-II region, with Ba/Sr/Ca-balanced CTS peaking at 1007 nm. Subtle Mg-doping further induces a hypsochromic shift and enhances fluorescence lifetimes. Comprehensive optical characterization with quantum yields reaching 34% and frame-rate performance exceeding 200 fps, demonstrates the photophysical robustness of these nanosheets. Enabled by their stability, brightness, and tunability, CTS-NS function as potent contrast agents for advanced in vivo imaging, showcased through transcranial microcirculation mapping and macrophage tracking using diffuse optical localization imaging (DOLI). This work highlights a path toward next-generation NIR-II probes for biological diagnostics and optical therapeutics.
