Browsing by Author "Udhayakumari, Duraisamy"

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A dual-mode chemosensor: Highly selective colorimetric fluorescent probe for Cu2+ and F- ions
(2014-12-01)
Udhayakumari, Duraisamy
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Velmathi, Sivan
;
Chen, Wei-Chieh
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Wu, Shu-Pao
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應用化學系
N-Phenylthiosemicarbazones (R1-R4) have been synthesized and characterized by various spectroscopic techniques. The sensors (R1-R4) exhibited highly selective and sensitive recognition toward Cu2+ and F ions over other cations and anions via visual color change. Sensors showed a significant fluorescent enhancement toward Cu2+ in aqueous medium and found a sub-nanomolar detection limit with good quantum yield. R1 displayed high selectivity to Cu2+ over other interference ions with 89-fold fluorescence intensity enhancement upon the addition of 2 equiv. of Cu2+. In addition, the turn-on fluorescent changes upon the addition of Cu2+, is also applied in cell imaging. (C) 2014 Elsevier B.V. All rights reserved.
A pyrene-linked thiourea as a chemosensor for cations and simple fluorescent sensor for picric acid
(2015-01-01)
Udhayakumari, Duraisamy
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Velmathi, Sivan
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Venkatesan, Parthiban
;
Wu, Shu-Pao
;
應用化學系
A simple pyrene- linked thiourea 1 has been synthesized and shown to act as a fluorescent and visual sensor for the detection of Cu2+ and Hg2+ ions. The sensor showed effective detection of Cu2+ and Hg2+ at a low detection limit. Receptor 1 has been successfully applied in the fluorescence imaging of Cu2+ and Hg2+ ions in living cells. Receptor 1 also selectively detects picric acid via both color change and fluorescence change.
Anthracene coupled thiourea as a colorimetric sensor for F-/Cu2+ and fluorescent sensor for Hg2+/picric acid
(2015-05-01)
Udhayakumari, Duraisamy
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Velmathi, Sivan
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Venkatesan, Parthiban
;
Wu, Shu-Pao
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應用化學系
A new dual chemosensor (Z)-2-(anthracen-9-ylmethylene)-N-phenylhydrazinecarbothioamide R1 was synthesized by incorporating a thiourea derivative as a binding unit and an anthracene group as a fluorescence signalling unit. R1 selectively binds with Cu2+ and He2+ ions in aqueous medium. R1 exhibits highly selective recognition towards F- ion and picric acid in organic medium. Fluorescence quenching was observed in case of R1 with Cu2+ and He+ ions over commonly coexistent metal ions. Furthermore, fluorescence imaging experiments of Cu2+ and Hg2+ ions in living RAW 264.7 cells demonstrate its value of practical applications in biological systems. (C) 2015 Elsevier B.V. All rights reserved.
Heterocyclic ring based colorimetric and fluorescent chemosensor for transition metal ions in an aqueous medium
(2015-02-01)
Udhayakumari, Duraisamy
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Velmathi, Sivan
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Boobalan, Maria Susai
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Venkatesan, Parthiban
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Wu, Shu-Pao
Heterocyclic ring based R1-R3 have been synthesized from the simple condensation method. R1-R3 exhibit highly selective and sensitive recognition towards transition metal ions in an aqueous medium via visual color change and were further confirmed by UV-vis and fluorescent spectroscopic methods. Fluorescent turn on and turn off behavior was observed for receptors tested with transition metal ions. The interaction of transition metal ions and receptors R1-R3 was confirmed to adopt 1:1 binding stoichiometry. Micromolar detection limit was found for R1-R3 with metal ions. DFT theoretical calculations were employed to understand the sensing mechanism of the sensors towards the metal ions. R1 and R2 were also successfully demonstrated as a fluorescent probe for detecting Cu2+ ions in living cells. (C) 2014 Elsevier B.V. All rights reserved.
Highly fluorescent probe for copper (II) ion based on commercially available compounds and live cell imaging
(2014-07-01)
Udhayakumari, Duraisamy
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Velmathi, Sivan
;
Sung, Yi-Ming
;
Wu, Shu-Pao
;
應用化學系
The commercially available 2, 3-diaminophenazine, 1,2-diamino-anthraquinone and 2, 4-dinitrophenylhydrazine (S1-S3) act as a colorimetric, fluorescent probes for selective detection of Cu2+ ions in aqueous medium over other metal ions. In presence of Cu2+, S1 shows fluorescent turn-on due to the inhibition of photoinduced electron transfer mechanism. The fluorescent probes S1-S3 detect Cu2+ ions in aqueous solution at nanomolar levels. Theoretical calculations were emploued to understand the sensing mechanism of the semsors towards Cu2+. S1, S2 and S3 were further applied for biological imaging to confirm that it can be used as a fluorescent probe for monitoring Cu2+ in living cells, and demonstrated its value in practical applications such as environmental and biological systems. (C) 2014 Elsevier B.V. All rights reserved.