Photographic Physi-Luminescence Assay Based on a Persistent Luminescence Nanoprobe.
Chemi- or bioluminescence assays have broad applications in biomedical analysis, yet they still suffer from a flash effect or difficulty in maintaining time synchronization during high-throughput assays. Persistent luminescence (PersL) nanoprobes are able to emit photons for a rather long time without any chemical reactions and have promising applications in developing a physi-luminescence assay. Herein, SiO2/Zn2SiO4:Mn,Yb,Ge nanoparticles (MYG, Zn/Si/Mn/Yb/Ge molar ratio, 2/15/0.003/0.060/0.100) were synthesized with PersL properties at 525 nm. Mesoporous silica nanoparticles were used as a nanotemplate to control the size and morphology, which allowed for gram-scale production (1.1277 g). Ge was found to be an efficient codopant to realize the enhanced PersL of MYG. A hydrophobic azo dye, Sudan III, was loaded onto the MYG surface to form a quenched MYG-S nanoprobe. Under 254 nm UV illumination, Sudan III was oxidized by H2O2, and PersL was recovered. The "OFF-ON" PersL property of MYG-S was applied to develop a physi-luminescence assay method for H2O2, glucose, and glucose oxidase in serum. As the PersL of the samples in a 96-well plate was activated by simultaneous UV illumination rather than by adding chemicals, high-throughput photographic luminescence analysis was realized with accuracy and repeatability. Our research indicates the promising applications of PersL nanoprobes in developing a physi-luminescence assay.