Photochemical properties and bio-applications of upconversion nanoparticles

Abstract

Upconversion nanoparticles (UCNPs) are promising materials that emit visible light under NIR range excitation through a multi-photon process. Also, UCNPs have a great potential in bio-applications as their photo-stable properties, low toxicity, deep penetration depth, nonautofluorescence. Especially, UCNP has great photostability such as non-blinking and nonbleaching nature. Here, I report the ‘Stochastic Photon Emission (SPEM)’ from emissions of UCNPs at the microsecond timescales. This study represents of the dark periods UCNPs that seem to be blinking. Also, the kinetic information of SPEM was used to identify the upconversion pathway by observing the difference between the green and red emission of UCNPs. Secondly, I suggest cellular dilution effects of upconversion nanoparticles when division occurs. I measured the dilution ratio of UCNPs during cell division that could discuss the anticancer effect of drugs on UCNPs on cancer treatments.