• Title/Summary/Keyword: Fluorophore

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Comparative study of 2-nitroimidazole-fluorophore-conjugated derivatives with pimonidazole for imaging tumor hypoxia

  • Seelam, Sudhakara Reddy;Hong, Mi Kyung;Lee, Yun-Sang;Jeong, Jae Min
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.5 no.2
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    • pp.101-112
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    • 2019
  • Herein, 2-nitroimidazole-fluorophore conjugates were synthesized by linking 2-nitroimidazole and FITC or RITC via thiourea bonds. The prepared derivatives were stable for 2 h in Dulbecco's modified Eagle's medium (DMEM) at 37 ℃. The novel conjugates were studied for their in vitro uptake under hypoxic conditions using U87MG and CT-26 cell lines, showing significantly higher uptakes in hypoxic than normoxic cells. Immunohistochemical analysis confirmed hypoxia in U87MG and CT-26 xenografted tumor tissues. Moreover, the prepared conjugates were evaluated by in vivo experiments after intravenous injection in U87MG and CT-26 xenografted mice. Hypoxia was confirmed by immunohistochemistry of the prepared derivatives with co-injected pimonidazole. Confocal microscopy of the prepared derivatives showed strong fluorescence in hypoxic tumor tissues correlated with the pimonidazole distribution. This suggested that the 2-nitroimidazole-fluorophore conjugates are promising optical imaging probes for tumor hypoxia and are promising substitutes for pimonidazole immunohistochemistry, which requires a multi-step procedure of incubation involving antibody, second antibody, dye, hydrogen peroxide, and multiple washing steps.

Simple Ratiometric Fluorophore for the Selective Detection of Mercury through Hg(II)-Mediated Oxazole Formation

  • Lee, Hee-Jin;Kim, Hae-Jo
    • Bulletin of the Korean Chemical Society
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    • v.32 no.11
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    • pp.3959-3962
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    • 2011
  • A simple propargylamide-fuctionalized chemodosimeter was prepared for the ratiometric fluorescence detection of mercuric ions in HEPES buffer. The chemodosimeter exhibited $Hg^{2+}$-induced propargyl amide-tooxazole transformation, with a significant accompanying ratiometric change in fluorescence. It afforded high selectivity for mercuric ion detection without any competitive inhibition by common alkali, alkaline earth, or other transition metal ions. The probe showed a $17{\times}10^{-6}M$ detection limit for $Hg^{2+}$ ions and potential applicability for detecting aqueous $Hg^{2+}$ ions.

Fluorescece Microscope using Total Internal Reflection for Measuring Biochip (내부 전반사 방식에 의한 바이오칩 측정 장비)

  • Bae, Soo-Jin;Kang, Uk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.9
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    • pp.1694-1698
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    • 2007
  • This study suggests a new fluorescence microscope to observe micro-samples within fluorophore in a variety of biomedical fields including the fluorescence analysis of a biochip, such as a DNA micro-array. A fluorescence microscope is a device for irradiating light onto a micro-object, executing an excitation and fluorescence emission process. In this study, it adopts a total internal reflection fluorescence(TIRF) method to excite a whole micro-sample substrate different from an existing way which uses an evanescent wave resulting from a total internal reflection on the micro-sample surface. Suggested TIRF microscope can reduce optical noise and obtain images with higher sensitivity thus obtain precise information about the density, quantity, location, etc. of a flurophore, and can simultaneously process separate images even when plurality of fluorophores having different excitation and fluorescent wavelength ranges is distributed, thus easily obtain information about the fluorophores.

Fluorescent Compounds Having the Spaced and Integrated Type Receptors

  • Choi, Chang-Shik
    • Rapid Communication in Photoscience
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    • v.5 no.1
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    • pp.1-7
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    • 2016
  • Fluorescent receptors have gained much attention because of their usefulness in analysis and clarification of the roles of biomolecules in living systems. Molecular structures of the integrated type including that the receptor itself is fluorescent, and play an important role in having the functionality or selectivity of the fluorescent compounds. These spaced type fluorescent receptors are required to have special molecular design in order to transmit the information of molecular recognition to the fluorescent unit through the spacer unit. Compared with the spaced type fluorescent receptors, number of the integrated type receptors is limited due to the difficult molecular design and synthesis. Modification of alteration of the fluorophore frequently caused deterioration of the fluorescent property. Various spaced type and integrated type fluorescent receptors including switch on-off receptors are introduced in this article.

Chemiluminescence Properties of Polymeric Fluorophores Containing Distyrylarylene Unit

  • Lee, Hui U;Kim, Cheol Hui;Gong, Myeong Seon
    • Bulletin of the Korean Chemical Society
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    • v.22 no.7
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    • pp.727-731
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    • 2001
  • Conjugated-non-conjugated alternating block copolymers containing distyrylarylene units were synthesized via Wittig reaction for chemiluminescent fluorophores. The polymers were differentiated from others by the presence of aromatic unit in the chromophoric block. When UV-VIS, photoluminescence and chemiluminescence spectra of these materials were compared with copolymers, a strong bathochromic effect was observed. A more pronounced red shift and higher chemiluminscence efficiency were observed in the polymer with anthracene ring. Sodium salicylate-catalyzed reaction of bis(2-carbopentyloxy-3,5,6-trichlorophenyl) oxalate with hydrogen peroxide produced a strong chemiluminescence from blue to yellow-green light emission with wavelength of 450-537 nm in the presence of the fluorophore. The chemiluminescent intensity decayed exponentially. The glow of chemiluminescence maintained more than l2 hr and was visible with the naked eye.

Synthesis and Luminescent Characteristics of Anthracene Fluoroionophores (안트라센 형광 단위를 가지는 Fluoroionophore의 합성 및 발광특성)

  • Jeon Young-Min;Kim Jong-Gyu;Jang Ji-Geun;Chang Ho-Jung;Kim Yung-Sup;Gong Myoung-Seon
    • Polymer(Korea)
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    • v.30 no.5
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    • pp.426-431
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    • 2006
  • Novel azacrown ether containing blue -light emitting anthracene fluorophore, 9,10-bis [p-(1-aza-18-crown-6)methylphenyl] anthracene (3) and N,N-bis [9-(p-methylphenyl) anthracenyl-methyl] -1,6-diaza-18-crown-6 (4) were prepared by reacting anthracene derivatives 1 and 2 with mono- and diaza-18-crown-6, respectively Also, crown ether containing fluorophore copolymer (5) were prepared by reacting 1,6-diaza-18-crown-6 with 1. Their fluorescence emission spectral studies were investigated by binding group I, group II and various metal cations. The fluorophores showed an absorption at ${\lambda}_{max}$= 372 nm and an emission at ${\lambda}_{max}$= 430 nm. pH Dependency of fluorescence emission intensity were examined to determine the optimum pH for the fluorophores.