SSC2025 Programme Booklet

Frequency-Converting Nanocrystals: A New Frontier in Nanophotonics Peony 4504 8 December 2:10pm

Xiaogang Liu National University of Singapore

Lanthanide-doped nanocrystals have emerged as a powerful class of optical materials for biological applications due to their unique photon management capabilities, including upconversion, downconversion, and persistent luminescence. These nanocrystals harness the ladder-like energy levels of lanthanide ions to achieve multi-wavelength emission with high photostability, deep tissue penetration, and minimal background autofluorescence, key attributes for advanced bioimaging and biosensing. Recent progress in the synthetic control, surface functionalization, and multiplexed encoding of lanthanide-doped nanocrystals has unlocked their potential for single-particle tracking, in vivo imaging, optogenetics, and theranostics. Moreover, their ability to transduce low-energy near-infrared excitation into visible or ultraviolet light enables spatiotemporally precise stimulation of biological processes, offering new avenues in neural modulation and controlled drug release. This talk highlights the latest breakthroughs in lanthanide nanocrystal-based biophotonics, emphasizing the mechanistic insights, design principles, and biomedical integration strategies that underpin their performance. I also discuss the emerging convergence of lanthanide nanocrystals with artificial intelligence, nanomedicine, and wearable technologies, envisioning a future where light-driven diagnostics and interventions are embedded into healthcare systems.

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