• Ceramist
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• v.21 no.3
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• pp.270-282
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• 2018

The increasing importance of biomedical imaging technology has led to the development of a variety of luminescent materials, including molecular fluorophores, fluorescent proteins, and quantum dots. Owing to their inherent disadvantages, such as insufficient chemical stability and limited biocompatability, their utilization has been limited with imaging only under highly optimized and controlled conditions. Recently, a new class of luminescent nanoparticles, upconversion nanoparticles (UCNPs), have been emerging as a practically useful nanoprobe for various bioimaging applications. The detailed synthesis, functionalization, properties and in-vitro / in-vivo applications of the UCNPs are introduced and discussed in this Review.