Unlocking NIR-II Photoluminescence in 2D Copper Tetrasilicate Nanosheets Through Flame Spray Synthesis
Robert Nißler a b, Inge Herrmann a b
a Department of Mechanical and Process Engineering, ETH Zürich, Zürich, Switzerland
b University Zurich Hospital
Proceedings of Emerging Light Emitting Materials 2025 (EMLEM25)
La Canea, Greece, 2025 October 8th - 10th
Organizers: Maksym Kovalenko and Grigorios Itskos
Oral, Robert Nißler, presentation 020
Publication date: 17th July 2025

Expanding fluorescence bioimaging into the second near-infrared spectrum (NIR-II, 1000-1700 nm) unlocks advanced possibilities for diagnostics and therapeutics, offering superior tissue penetration and resolution. Two-dimensional copper tetrasilicate (CTS) pigments (MCuSi4O10, M = Ca, Sr, Ba) are known for their brightness and stability, yet synthetic challenges have curbed their integration into bioimaging. Here, we introduce flame-spray-pyrolysis (FSP) as a versatile and scalable synthesis approach to produce ultra-bright, metastable CTS nanosheets (NS) by annealing multi-element metal oxide nanoparticles into 2D crystals through calcination or laser irradiation. Group-II ion incorporation shifts emission into the NIR-II range, with Ba0.33Sr0.33Ca0.33CuSi4O10 peaking at 1007 nm, while minor Mg-doping induces a hypsochromic shift and extends fluorescence lifetimes. The engineered CTS achieve quantum yields up to 34%, supporting NS high-frame-rate imaging (>200 fps). These unique properties enable CTS-NS to serve as powerful contrast agents for super-resolution NIR bioimaging, demonstrated in vivo through transcranial microcirculation mapping and macrophage tracking in mice using diffuse optical localization imaging (DOLI). This pioneering synthesis strategy unlocks wavelength-tunable NS for advanced NIR-II bioimaging applications.

 

 

© FUNDACIO DE LA COMUNITAT VALENCIANA SCITO
We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info