TY - JOUR
T1 - High-Contrast Visualization of Upconversion Luminescence in Mice Using Time-Gating Approach
AU - Zheng, Xianlin
AU - Zhu, Xingjun
AU - Lu, Yiqing
AU - Zhao, Jiangbo
AU - Feng, Wei
AU - Jia, Guohua
AU - Wang, Fan
AU - Li, Fuyou
AU - Jin, Dayong
PY - 2016/4/5
Y1 - 2016/4/5
N2 - Optical imaging through the near-infrared (NIR) window provides deep penetration of light up to several centimeters into biological tissues. Capable of emitting 800 nm luminescence under 980 nm illumination, the recently developed upconversion nanoparticles (UCNPs) suggest a promising optical contrast agent for in vivo bioimaging. However, presently they require high-power lasers to excite when applied to small animals, leading to significant scattering background that limits the detection sensitivity as well as a detrimental thermal effect. In this work, we show that the time-gating approach implementing pulsed illumination from a NIR diode laser and time-delayed imaging synchronized via an optical chopper offers detection sensitivity more than 1 order of magnitude higher than the conventional approach using optical band-pass filters (S/N, 47321/6353 vs 5339/58), when imaging UCNPs injected into Kunming mice. The pulsed laser illumination (70 μs ON in 200 μs period) also reduces the overall thermal accumulation to 35% of that under the continuous-wave mode. Technical details are given on setting up the time-gating unit comprising an optical chopper, a pinhole, and a microscopy eyepiece. Being generally compatible with any camera, this provides a convenient and low cost solution to NIR animal imaging using UCNPs as well as other luminescent probes. (Figure Presented).
AB - Optical imaging through the near-infrared (NIR) window provides deep penetration of light up to several centimeters into biological tissues. Capable of emitting 800 nm luminescence under 980 nm illumination, the recently developed upconversion nanoparticles (UCNPs) suggest a promising optical contrast agent for in vivo bioimaging. However, presently they require high-power lasers to excite when applied to small animals, leading to significant scattering background that limits the detection sensitivity as well as a detrimental thermal effect. In this work, we show that the time-gating approach implementing pulsed illumination from a NIR diode laser and time-delayed imaging synchronized via an optical chopper offers detection sensitivity more than 1 order of magnitude higher than the conventional approach using optical band-pass filters (S/N, 47321/6353 vs 5339/58), when imaging UCNPs injected into Kunming mice. The pulsed laser illumination (70 μs ON in 200 μs period) also reduces the overall thermal accumulation to 35% of that under the continuous-wave mode. Technical details are given on setting up the time-gating unit comprising an optical chopper, a pinhole, and a microscopy eyepiece. Being generally compatible with any camera, this provides a convenient and low cost solution to NIR animal imaging using UCNPs as well as other luminescent probes. (Figure Presented).
UR - http://www.scopus.com/inward/record.url?scp=84964310776&partnerID=8YFLogxK
UR - http://purl.org/au-research/grants/arc/FT130100517
U2 - 10.1021/acs.analchem.5b04626
DO - 10.1021/acs.analchem.5b04626
M3 - Article
C2 - 26916365
AN - SCOPUS:84964310776
SN - 0003-2700
VL - 88
SP - 3449
EP - 3454
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 7
ER -