Non-blinking and photostable upconverted luminescence from single lanthanide-doped nanocrystals

作者：Wu Shiwei; Han Gang; Milliron Delia J; Aloni Shaul; Altoe Virginia; Talapin Dmitri V; Cohen Bruce E^*; Schuck P James

来源：Proceedings of the National Academy of Sciences, 2009, 106(27): 10917-10921.

DOI：10.1073/pnas.0904792106

• bio-imaging
• fluorescence
• nanoparticle
• single molecule
• phosphorescence

The development of probes for single-molecule imaging has dramatically facilitated the study of individual molecules in cells and other complex environments. Single-molecule probes ideally exhibit good brightness, uninterrupted emission, resistance to photobleaching, and minimal spectral overlap with cellular autofluorescence. However, most single-molecule probes are imperfect in several of these aspects, and none have been shown to possess all of these characteristics. Here we show that individual lanthanide-doped upconverting nanoparticles (UCNPs)-specifically, hexagonal phase NaYF(4) (beta-NaYF(4)) nanocrystals with multiple Yb(3+) and Er(3+) dopants-emit bright anti-Stokes visible upconverted luminescence with exceptional photostability when excited by a 980-nm continuous wave laser. Individual UCNPs exhibit no on/off emission behavior, or "blinking," down to the millisecond time-scale, and no loss of intensity following an hour of continuous excitation. Amphiphilic polymer coatings permit the transfer of hydrophobic UCNPs into water, resulting in individual water-soluble nanoparticles with undiminished photophysical characteristics. These UCNPs are endocytosed by cells and show strong upconverted luminescence, with no measurable anti-Stokes background autofluorescence, suggesting that UCNPs are ideally suited for single-molecule imaging experiments.

• 出版日期2009-7-7