Lanthanide-doped nanoparticles,which contain lanthanide ions doped in an inorganic host,can generate wide wavelength range emissions corresponding to inner shell 4f-4f transitions of lan-thanide ions [1-3].Unfortunately,lanthanide 4f transitions have a narrow absorption band and small absorption cross-section(10-20 cm2) when compared with organic dye molecules (around 10-17-10-16 cm2),posing a critical brightness performance limit of lanthanide ions [4,5].Thus,dye-sensitized nanoparticles are emerging to tackle this problem for brighter luminescence through enhanced absorption efficiency when organic dyes are anchored on the surface of lanthanide-doped nanoparticles [6].In 2012,Zou et al.[7] achieved 1100 times stronger emission in IR806-sensitized lanthanide-doped nanoparticles than that in nanoparti-cles without dye sensitizers.In 2018,Garfield et ai.[8] demon-strated that high lanthanide doping in inorganic nanocrystals can shift the energy level of the excited organic dye.This shift can bet-ter overlap the absorption band of Yb3+ and yield emission inten-sity up to 33,000 times stronger.Despite these achievements in increased absorption efficiencies and large emission enhancement,existing research still lacks a general mechanism study of the inter-actions between organic dyes and inorganic nanoparticles.