Deep, high contrast microscopic cell imaging using three-photon luminescence of beta-(NaYF4:Er3+/NaYF4) nanoprobe excited by 1480-nm CW laser of only 1.5-mW
2015 (English)In: Biomedical Optics Express, ISSN 2156-7085, Vol. 6, no 5, 1857-1866 p.Article in journal (Refereed) Published
It is challenging to achieve deep microscopic imaging for the strong scattering in biotissue. An efficient three-photon luminescence can effectively increase the penetration depth. Here we report that beta-NaYF4: Er3+/NaYF4 UCNPs were excited by a 1480-nm CW-laser and emitted 543/653-nm light through a three-photon process. With the merit of the hexagonal crystal phase, sub-milliwatt laser power was utilized to excite the UCNP-probed cells to minimize the heating effect. The polymer-coated UCNPs were shown to be harmless to cells. The deep, high contrast in vitro microscopic imaging was implemented through an artificial phantom. Imaging depth of 800 mu m was achieved using only 1.5 mW excitation and a 0.7 NA objective. The green/red emission intensities ratio after penetrating the phantom was studied, indicating that longer emission wavelength is preferred for deep multiphoton microscopy. The proposed and demonstrated beta-UCNPs would have great potential in three-photon microscopy. (C) 2015 Optical Society of America
Place, publisher, year, edition, pages
2015. Vol. 6, no 5, 1857-1866 p.
Up-Conversion Nanoparticles, Upconverting Nanoparticles, Multiphoton Microscopy, High-Resolution, NM, Excitation, Nanocrystals, Lanthanide
Biochemistry and Molecular Biology Radiology, Nuclear Medicine and Medical Imaging
IdentifiersURN: urn:nbn:se:kth:diva-169139DOI: 10.1364/BOE.6.001857ISI: 000353927100023ScopusID: 2-s2.0-84942897255OAI: oai:DiVA.org:kth-169139DiVA: diva2:820422