title: Organic Dots Based on AIEgens for Two-Photon Fluorescence Bioimaging.
abstract: Two-photon fluorescence imaging technique is a powerful bioanalytical approach in terms of high photostability, low photodamage, high spatiotemporal resolution. Recently, fluorescent organic dots comprised of organic emissive cores and a polymeric matrix are emerging as promising contrast reagents for two-photon fluorescence imaging, owing to their numerous merits of high and tunable fluorescence, good biocompatibility, strong photobleaching resistance, and multiple surface functionality. The emissive core is crucial for organic dots to get high brightness but many conventional chromophores often encounter a severe problem of fluorescence quenching when they form aggregates. To solve this problem, fluorogens featuring aggregation-induced emission (AIE) can fluoresce strongly in aggregates, and thus become ideal candidates for fluorescent organic dots. In addition, two-photon absorption property of the dots can be readily improved by just increase loading contents of AIE fluorogen (AIEgen). Hence, organic dots based on AIEgens have exhibited excellent performances in two-photon fluorescence in vitro cellular imaging, and in vivo vascular architecture visualization of mouse skin, muscle, brain and skull bone. In view of the rapid advances in this important research field, here, we highlight representative fluorescent organic dots with an emissive core of AIEgen aggregate, and discuss their great potential in bioimaging applications.
authors.affiliation: School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
authors.forename: Xiaoding
authors.initials: X
authors.lastname: Lou
authors.affiliation: State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China.
authors.forename: Zujin
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China.|Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China.|Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Hong Kong, China.
authors.forename: Ben Zhong
authors.initials: BZ
authors.lastname: Tang
mesh_terms: D000818:Animals; D005453:Fluorescence; D006801:Humans; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods; D061848:Optical Imaging / Q000379:methods*; D017785:Photons
keywords: aggregation-induced emissions; bioimaging; nanoparticles; organic dots; two-photon fluorescence