TY - JOUR
T1 - Semiconducting Polymer Dots with Dual-Enhanced NIR-IIa Fluorescence for Through-Skull Mouse-Brain Imaging
AU - Zhang, Zhe
AU - Fang, Xiaofeng
AU - Liu, Zhihe
AU - Liu, Haichao
AU - Chen, Dandan
AU - He, Shuqing
AU - Zheng, Jie
AU - Yang, Bing
AU - Qin, Weiping
AU - Zhang, Xuanjun
AU - Wu, Changfeng
N1 - Publisher Copyright:
© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2020/2/24
Y1 - 2020/2/24
N2 - Fluorescence probes in the NIR-IIa region show drastically improved imaging owing to the reduced photon scattering and autofluorescence in biological tissues. Now, NIR-IIa polymer dots (Pdots) are developed with a dual fluorescence enhancement mechanism. First, the aggregation induced emission of phenothiazine was used to reduce the nonradiative decay pathways of the polymers in condensed states. Second, fluorescence quenching was minimized by different levels of steric hindrance to further boost the fluorescence. The resulting Pdots displayed a fluorescence QY of ca. 1.7 % in aqueous solution, suggesting an enhancement of ca. 21 times in comparison with the original polymer in tetrahydrofuran (THF) solution. Small-animal imaging by using the NIR-IIa Pdots exhibited a remarkable improvement in penetration depth and signal to background ratio, as confirmed by through-skull and through-scalp fluorescent imaging of the cerebral vasculature of live mice.
AB - Fluorescence probes in the NIR-IIa region show drastically improved imaging owing to the reduced photon scattering and autofluorescence in biological tissues. Now, NIR-IIa polymer dots (Pdots) are developed with a dual fluorescence enhancement mechanism. First, the aggregation induced emission of phenothiazine was used to reduce the nonradiative decay pathways of the polymers in condensed states. Second, fluorescence quenching was minimized by different levels of steric hindrance to further boost the fluorescence. The resulting Pdots displayed a fluorescence QY of ca. 1.7 % in aqueous solution, suggesting an enhancement of ca. 21 times in comparison with the original polymer in tetrahydrofuran (THF) solution. Small-animal imaging by using the NIR-IIa Pdots exhibited a remarkable improvement in penetration depth and signal to background ratio, as confirmed by through-skull and through-scalp fluorescent imaging of the cerebral vasculature of live mice.
KW - NIR-II fluorescence imaging
KW - aggregation-induced emission
KW - molecular engineering
KW - polymer dots
KW - semiconducting polymers
UR - http://www.scopus.com/inward/record.url?scp=85078653917&partnerID=8YFLogxK
U2 - 10.1002/anie.201914397
DO - 10.1002/anie.201914397
M3 - Article
C2 - 31823447
AN - SCOPUS:85078653917
SN - 1433-7851
VL - 59
SP - 3691
EP - 3698
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
IS - 9
ER -