NIR Ratiometric Luminescence Detection of pH Fluctuation in Living Cells with Hemicyanine Derivative-Assembled Upconversion Nanophosphors
writer：Li, H. X.; Dong, H.; Yu, M. M.; Liu, C. X.; Li, Z. X *.; Wei, L. H.; Sun, L. D. *.; Zhang, H. Y.*
keywords：NIR，UCNPs
source：期刊
specific source：Anal. Chem., 2017, 89, 8863?8869
Issue time：2017年
: It is crucial for cell physiology to keep the
homeostasis of pH, and it is highly demanded yet challenging to
develop luminescence resonance energy transfer (LRET)-based
near-infrared (NIR) ratiometric luminescent sensor for the
detection of pH fluctuation with NIR excitation. As promising
energy donors for LRET, upconversion nanoparticles (UCNPs)
have been widely used to fabricate nanosensors, but the relatively
low LRET efficiency limits their application in bioassay. To improve
the LRET efficiency, core/shell/shell structured β-NaGdF4@
NaYF4:Yb,Tm@NaYF4 UCNPs were prepared and decorated with
hemicyanine dyes as an LRET-based NIR ratiometric luminescent
pH fluctuation-nanosensor for the first time. The as-developed
nanosensor not only exhibits good antidisturbance ability, but it also
can reversibly sense pH and linearly sense pH in a range of 6.0?9.0 and 6.8?9.0 from absorption and upconversion emission
spectra, respectively. In addition, the nanosensor displays low dark toxicity under physiological temperature, indicating good
biocompatibility. Furthermore, live cell imaging results revealed that the sensor can selectively monitor pH fluctuation via
ratiometric upconversion luminescence behavior.