Controlled synthesis, bioimaging and toxicity assessments in strong red emitting Mn2+ doped NaYF4:Yb3+/Ho3+ nanophosphors. Issue 59 (2nd June 2016) - Reddy, K. L.
Abstract : Rare earth, Yb 3+ /Ho 3+ doped NaYF4 nanophosphors co-doped with Mn 2+ showed enhanced red emission under NIR irradiation and were successfully used for cancer cell imaging. Abstract : Rare earth, Yb 3+ /Ho 3+ doped NaYF4 nanophosphors showed augmentation of visible green and red light emission by the introduction of Mn 2+ as a co-dopant. Nanophosphors were characterized for their morphology and upconversion (UC) fluorescence, as a function of co-dopant concentration. The effect of Mn 2+ doping has been investigated to explore the UC mechanism of the phosphors. With the introduction of Mn 2+, the intensity of all the emission bands was increased, in particular the red band, which was most significant at 40 mol% doping. A possible mechanism for the enhancement of the red emission has been proposed. The prepared UC nanoparticles were functionalized with polyethylene glycol–polyethylene imine co-polymer to make them water dispersible and successfully applied for cancer cell imaging.