pH‐Responsive Torpedo‐Like Persistent Luminescence Nanoparticles for Autofluorescence‐Free Biosensing and High‐Level Information Encryption

Persistent luminescent nanoparticles (PLNPs) with intrinsic stimuli-responsive properties are desirable because of no autofluorescence background and natural responsive luminescence. However, the stimuli-responsive features of pure PLNPs have been unexplored. Here we show a facile one-pot hydrothermal synthesis of green-emitting Zn₂ GeO₄ :Mn²⁺ ,Pr³⁺ nanoparticles (ZGMP) with regular shape, uniform size and good afterglow luminescent performance. We also report the pH stimuli-responsive luminescent behavior of ZGMP and its possible mechanism. Taking the intriguing feature of pH responsive persistent luminescence, we explore ZGMP as autofluorescence-free probes to achieve stimuli-activated signal switch for biosensing by integrating enzyme catalysis reaction mediated pH modulation. The pH-responsive persistent luminescence also makes ZGMP promising for high-level information encryption.