Modulating the Luminescence of Upconversion Nanoparticles with Heavy Metal Ions: A New Strategy for Probe Design

摘要

Upconversion nanopartides (UCNPs) are attracting increasing attention in biosensing and imaging. The design of UCNP-based probes currently relies exclusively on the lumineseenCe resonance energy transfer (LRET) principle. The prerequisite spectral overlap in LRET leads to, limited flexibility in probe design thus hindering the construction and application cif upconversion (UC) probes. To change this situation, we herein present a new approach,to construct UC probes by use of heavy metal ion-induced quenching. We reveal that heavy metal ions can quench the upconversion luminescence (UCL) to >95% without the occurrence of spectral overlap. A proof-of-concept UC probe for bdothiols by manipulating Cu2+ as the switch of luminescence exhibits satisfying performance both in vitro and in bioimaging. This is the first report of a UC probe. utilizing heavy metal ions to govern the read-out signal. The strategy, is much simpler than the LRET principle and highly efficient, which prolrides a new way to design, and apply UCNP-based probes.