유영민 (이화여자대학교, MIT) | 한빛사논문 > 한빛사

상위피인용논문

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이화여자대학교, MIT

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J. Am. Chem. Soc., 16 November 2011, 133 (45), pp 18328–18342 | DOI: 10.1021/ja207163r Phosphorescent Sensor for Biological Mobile Zinc

Abstract

Youngmin You^*†‡, Sumin Lee^‡, Taehee Kim^§, Kei Ohkubo^⊥, Weon-Sik Chae^∥, Shunichi Fukuzumi^‡⊥, Gil-Ja Jhon^§, Wonwoo Nam^*‡, and Stephen J. Lippard^*†

Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
^‡Department of Bioinspired Science and ^§Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
^⊥Department of Material and Life Science, Graduate School of Engineering, Osaka University, ALCA, Japan Science and Technology Agency, Suita, Osaka 565-0871, Japan
^∥Korea Basic Science Institute, Gangneung Center, Gangneung, Gangwondo 210-702, Korea

^*Corresponding authors

Abstract
A new phosphorescent zinc sensor (ZIrF) was constructed, based on an Ir(III) complex bearing two 2-(2,4-difluorophenyl)pyridine (dfppy) cyclometalating ligands and a neutral 1,10-phenanthroline (phen) ligand. A zinc-specific di(2-picolyl)amine (DPA) receptor was introduced at the 4-position of the phen ligand via a methylene linker. The cationic Ir(III) complex exhibited dual phosphorescence bands in CH₃CN solutions originating from blue and yellow emission of the dfppy and phen ligands, respectively. Zinc coordination selectively enhanced the latter, affording a phosphorescence ratiometric response. Electrochemical techniques, quantum chemical calculations, and steady-state and femtosecond spectroscopy were employed to establish a photophysical mechanism for this phosphorescence response. The studies revealed that zinc coordination perturbs nonemissive processes of photoinduced electron transfer and intraligand charge-transfer transition occurring between DPA and phen. ZIrF can detect zinc ions in a reversible and selective manner in buffered solution (pH 7.0, 25 mM PIPES) with K_d = 11 nM and pK_a = 4.16. Enhanced signal-to-noise ratios were achieved by time-gated acquisition of long-lived phosphorescence signals. The sensor was applied to image biological free zinc ions in live A549 cells by confocal laser scanning microscopy. A fluorescence lifetime imaging microscope detected an increase in photoluminescence lifetime for zinc-treated A549 cells as compared to controls. ZIrF is the first successful phosphorescent sensor that detects zinc ions in biological samples.

논문정보

형식Research article
게재일2011년 11월 (BRIC 등록일 2014-12-16)
연구진국내(교신)+국외 연구진
분야
피인용횟수60회 이상 인용된 논문

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