title: Near-IR Two-Photon Fluorescent Sensor for K(+) Imaging in Live Cells.
abstract: A new two-photon excited fluorescent K(+) sensor is reported. The sensor comprises three moieties, a highly selective K(+) chelator as the K(+) recognition unit, a boron-dipyrromethene (BODIPY) derivative modified with phenylethynyl groups as the fluorophore, and two polyethylene glycol chains to afford water solubility. The sensor displays very high selectivity (>52-fold) in detecting K(+) over other physiological metal cations. Upon binding K(+), the sensor switches from nonfluorescent to highly fluorescent, emitting red to near-IR (NIR) fluorescence. The sensor exhibited a good two-photon absorption cross section, 500 GM at 940 nm. Moreover, it is not sensitive to pH in the physiological pH range. Time-dependent cell imaging studies via both one- and two-photon fluorescence microscopy demonstrate that the sensor is suitable for dynamic K(+) sensing in living cells.
authors.affiliation: †Department of Chemistry, University of Central Florida, Orlando, Florida 32816, United States.
authors.forename: Binglin
authors.initials: B
authors.lastname: Sui
authors.affiliation: †Department of Chemistry, University of Central Florida, Orlando, Florida 32816, United States.
authors.forename: Xiling
authors.initials: X
authors.lastname: Yue
authors.affiliation: †Department of Chemistry, University of Central Florida, Orlando, Florida 32816, United States.
authors.forename: Bosung
authors.initials: B
authors.lastname: Kim
authors.affiliation: †Department of Chemistry, University of Central Florida, Orlando, Florida 32816, United States.|‡College of Science and Liberal Arts, New Jersey Institute of Technology, Newark, New Jersey 07102, United States.|§School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, P.R. China.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Belfield
mesh_terms: D001896:Boron Compounds / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D045325:HCT116 Cells; D006801:Humans; D007477:Ions / Q000737:chemistry; D036641:Microscopy, Fluorescence, Multiphoton; D017785:Photons; D011188:Potassium / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D005456:Fluorescent Dyes; D007477:Ions; D011188:Potassium
keywords: cell imaging; fluorescent sensors; potassium sensors; two-photon absorption; two-photon fluorescence microscopy