Persistent Luminescence Nanoparticle-Based Biosensors

Persistent luminescence nanoparticles (PLNPs) are unique optical nanomaterials that emit a long-lasting afterglow in the absence of real-time excitation, enabling biosensing with near-zero background interference. This review summarizes recent advances in PLNP-based biosensing, highlighting how persistent luminescence improves analytical sensitivity, specificity, and operational simplicity in biological environments. We first outline foundational principles for constructing PLNP biosensors, including signal transduction via (1) analyte-regulated luminescence resonance energy transfer, (2) capture and enrichment of PLNPs for time-gated readout, and (3) ratiometric persistent luminescence. We then comprehensively discuss sensing strategies across major analyte classes, including biomolecules, small molecules, ions, and physiological parameters, such as local temperature. Finally, we examine current challenges in PLNP synthesis, surface engineering, multiplexing, and biosafety, and outline future directions toward next-generation persistent luminescence biosensors with enhanced brightness, programmability, and translational potential. Together, these developments position PLNPs as powerful and increasingly versatile platforms for high-performance biosensing and bioanalysis.