Tunable near infrared to ultraviolet upconversion luminescence enhancement in (α-NaYF4 :Yb,Tm)/CaF2 core/shell nanoparticles for in situ real-time recorded biocompatible photoactivation.

ABSTRACT

A family of upconverting nanoparticles (UCNPs) with a tunable UV enhancement is developed via a facile approach. The design leads to a maximum 9-fold enhancement in comparison with known optimal ß-phase core/shell UCNPs in water. A highly effective and rapid in situ real-time live-cell photoactivation is recorded for the first time with such nanoparticles.