Browsing by Author "Liu, Shi-Rong"

Now showing 1 - 14 of 14

A coumarin-based sensitive and selective fluorescent sensor for copper(II) ions
(2014-09-01)
Yeh, Jiun-Ting
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Chen, Wei-Chieh
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Liu, Shi-Rong
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Wu, Shu-Pao
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應用化學系
A new coumarin-derived fluorescent probe (1) exhibited significant fluorescence quenching in the presence of Cu2+ ions. Other metal ions, e.g. Ag+, Ca2+, Cd2+, Co2+, Fe2+, Fe3+, Hg2+, K+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+, produced only minor changes in the fluorescence of chemosensor 1. The binding ratio of the chemosensor-Cu2+ complexes was found to be 2 :1, according to Job plot experiments. The association constant (K-a) for Cu2+ binding with chemosensor 1 was found to be 9.56 x 10(9) M-2. The maximum fluorescence quenching caused by Cu2+ binding with chemosensor 1 occurred over a pH range of 5-9. Moreover, fluorescence microscopy experiments showed that chemosensor 1 could be used as a fluorescent probe for detecting Cu2+ in living cells.
A fluorescence turn-on probe for cysteine and homocysteine based on thiol-triggered benzothiazolidine ring formation
(2014-11-07)
Liu, Shi-Rong
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Chang, Chao-Yiu
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Wu, Shu-Pao
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應用化學系
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Department of Applied Chemistry
We synthesized a new coumarin-based probe TP, containing a disulfide moiety, to detect biothiols in cells. A fluorescence turn-on response is induced by the thiol-disulfide exchange of the probe, with subsequent intramolecular benzothiazolidine ring formation giving rise to a fluorescent product. The probe exhibits an excellent selectivity for cysteine (Cys) and homocysteine (Hcy) over glutathione (GSH) and other amino acids. The fluorescent probe also exhibits a highly sensitive fluorescence turn-on response to Cys and Hcy with detection limits of 0.8 mu M for Cys and 0.5 mu M for Hcy. In addition, confocal fluorescence microscopy imaging using RAW264.7 macrophages demonstrates that the probe TP could be an efficient fluorescent detector for thiols in living cells. (C) 2014 Elsevier B.V. All rights reserved.
A highly selective turn-on fluorescent chemosensor for copper(II) ion
(2010-12-18)
Wu, Shu-Pao
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Wang, Tzu-Hao
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Liu, Shi-Rong
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應用化學系
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Department of Applied Chemistry
A new pyrene derivative (1) containing a diaminomaleonitrile moiety exhibits high selectivity for Cu(2+) detection. Significant fluorescence enhancement was observed with chemosensor 1 in the presence of Cu(2+). However, the metal ions Ag(+), Ca(2+), Cd(2+), Co(2+), Fe(2+), Fe(3+), Hg(2+), Mg(2+), Mn(2+), Ni(2+), Pb(2+), and Zn(2+) produced only minor changes in fluorescence values for the system. The apparent association constant (K(a)) of Cu(2+) binding in chemosensor 1 was found to be 5.55x10(3) M(-1). The maximum fluorescence enhancement caused by Cu(2+) binding in chemosensor 1 was observed over the pH range 5-7.5. (C) 2010 Elsevier Ltd. All rights reserved.
A highly selective turn-on fluorescent chemosensor for copper(II) ion (vol 66, pg 9655, 2010)
(2011-04-01)
Wu, Shu-Pao
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Wang, Tzu-Hao
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Liu, Shi-Rong
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應用化學系
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Department of Applied Chemistry
A highly selective turn-on fluorescent sensor for Cu(II) based on an NSe2 chelating moiety and its application in living cell imaging
(2013)
Chou, Cho-Yen
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Liu, Shi-Rong
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Wu, Shu-Pao
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應用化學系
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Department of Applied Chemistry
In this study, a boron-dipyrromethene (BODIPY)-based fluorescent chemosensor CBS was developed for metal ion sensing. It was found that CBS containing an NSe2 moiety exhibited high selectivity for Cu2+ detection while CBS in the presence of Cu2+ displayed significant fluorescence enhancement. However, the metal ions Ag+, Ca2+, Co2+, Cr3+, Fe2+, Fe3+, Hg2+, K+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+ produced only minor changes in the fluorescence values of the system. The binding constant (K-a) of Cu2+ binding to CBS was found to be 7.28 x 10(3) M-1. The binding ratio of CBS-Cu2+ complexes was determined from the Job plot to be 1 : 1. The maximum fluorescence enhancement caused by Cu2+ binding to CBS was observed over the pH range 5.0-9.0. Additionally, the methyl thiazolyl tetrazolium (MTT) assay demonstrated the CBS to have low cytotoxicity. Confocal fluorescence microscopy imaging using RAW264.7 cells showed that CBS could be used as an effective fluorescent probe for detecting Cu2+ in living cells.
A new water-soluble fluorescent Cu(II) chemosensor based on tetrapeptide histidyl-glycyl-glycyl-glycine (HGGG)
(2009-08-18)
Wu, Shu-Pao
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Liu, Shi-Rong
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應用化學系
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Department of Applied Chemistry
A new water-soluble fluorescent chemosensor Fluor-HGGG was synthesized by linking a tetrapeptide histidyl-glycyl-glycyl-glycine (HGGG) with fluorescein via standard solid-phase 9-fluorenylmethoxycarbonyl (Fmoc) chemistry. Significant fluorescence quenching was observed with Fluor-HGGG in the presence of Cu(2+). Other metal ions including Ag(+) Ca(2+), Cd(2+), Co(2+), Fe(2+), Fe(3+), Hg(2+), Mn(2+), Ni(2+) and Zn(2+) produced only minor changes in fluorescence values for the system. The dissociation constant (K(D)) of Cu(2+) binding in Fluor-HGGG was found to be 37 mu M. The maximum fluorescence quenching caused by Cu(2+) binding in Fluor-HGGG was observed over the pH range 7-7.5. (C) 2009 Elsevier B.V. All rights reserved.
A Pyrene-based Highly Selective Turn-on Fluorescent Chemosensor for Iron(III) Ions and its Application in Living Cell Imaging
(2013-11-01)
Chung, Peter Kun
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Liu, Shi-Rong
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Wang, Hsuan-Fu
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Wu, Shu-Pao
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應用化學系
A new pyrene-based chemosensor (1) exhibits excellent selectivity for Fe3+ ions over a wide range of tested metal ions Ag+, Ca2+, Cd2+, Co2+, Cu2+, Fe2+, Hg2+, K+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+. The binding of Fe3+ to chemosensor 1 produces an emission band at 507 nm due to the formation of a Py-Py* excimer that is induced by Fe3+-binding. The binding ratio of 1-Fe3+ was determined to be 1:1 from a Job plot. The association constant of 1-Fe3+ complexes was found to be 1.27 x 10(4) M-1 from a Benesi-Hildebrand plot. In addition, fluorescence microscopy experiments show that 1 can be used as a fluorescent probe for detecting Fe3+ in living cells.
A Pyrene-based Highly Selective Turn-on Fluorescent Sensor for Copper(II) Ion and its Application in Live Cell Imaging
(2012-01-01)
Wu, Shu-Pao
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Huang, Zhen-Ming
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Liu, Shi-Rong
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Chung, Peter Kun
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應用化學系
A new pyrene derivative (chemosensor 1) containing a picolinohydrazide moiety exhibits high selectivity for Cu2+ ion detection in mixed aqueous media (CH3OH:H2O=7:3). Significant fluorescence enhancement was observed with chemosensor 1 in the presence of Cu2+. However, the metal ions Ag+, Ca2+, Cd2+, Co2+, Cu2+, Fe2+, Fe3+, Hg2+, K+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+ produced only minor changes in fluorescence for the system. The apparent association constant (K-a) of Cu2+ binding in chemosensor 1 was found to be 2.75*10(3) M-1. The maximum fluorescence enhancement caused by Cu2+ binding in chemosensor 1 was observed over the pH range 5-8. Moreover, by means of fluorescence microscopy experiments, it is demonstrated that 1 can be used as a fluorescent probe for detecting Cu2+ in living cells.
An NBD-based Sensitive and Selective Fluorescent Sensor for Copper(II) Ion
(2011-07-01)
Liu, Shi-Rong
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Wu, Shu-Pao
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應用化學系
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Department of Applied Chemistry
A new 7-nitrobenz-2-oxa-1,3-diazole (NBD) derived fluorescent probe (1) exhibiting high selectivity for Cu(2+) detection, produced significant fluorescence quenching in the presence of Cu(2+) ion, while the metal ions Ca(2+), Cd(2+), Co(2+), Fe(2+), Hg(2+), Mg(2+), Mn(2+), Ni(2+) and Zn(2+) produced only minor changes in fluorescence. The apparent association constant (K (a)) for Cu(2+) binding in chemosensor 1 was found to be 1.22 x 10(3) M(-1). The maximum fluorescence quenching activity caused by Cu(2+) binding to 1 was observed over the pH range 6-10.
Graphene Oxide Based Nanocarrier Combined with a pH-Sensitive Tracer: A Vehicle for Concurrent pH Sensing and pH-Responsive Oligonucleotide Delivery
(2015-06-03)
Hsieh, Chia-Jung
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Chen, Yu-Cheng
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Hsieh, Pei-Ying
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Liu, Shi-Rong
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Wu, Shu-Pao
We chemically tuned the oxidation status of graphene oxide (GO) and constructed a GO-based nanoplatform combined with a pH-sensitive fluorescence tracer that is designed for both pH sensing and pH-responsive drug delivery. A series of GOs oxidized to distinct degrees were examined to optimize the adsorption of the model drug, poly dT(30). We determined that highly oxidized GO was a superior drug-carrier candidate in vitro when compared to GOs oxidized to lesser degrees. In the cell experiment, the synthesized pH-sensitive rhodamine dye was first applied to monitor cellular pH; under acidic conditions, protonated rhodamine fluoresces at 588 mm (lambda(ex) = 561 nm). When the nanocarrier was introduced into cells, a rhodamine-triggered competition reaction occurred, and this led to the release of the oligonucleotides and the quenching of rhodamine fluorescence by GO. Our results indicate high drug loading (FAM-dT(30)/GO = 25/50 mu g/mL) and rapid cellular uptake (<0.5 h) of the nanocarrier which can potentially be used for targeted RNAi delivery to the acidic milieu of tumors.
Hydro gel light-guiding conjunction for absorptive type multi-ions detection
(2016-10-05)
Lin, Hung-Cheng
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Yang, Sean Tsungyeh
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Ng, Sock Hoon
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Zan, Hsiao-Wen
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Meng, Hsin-Fei
We present a novel miniaturized solid state sensor produced by embedding two optical fibers in a sensing hydro gel conjunction. The conjunction is a poly (2-hydroxyethyl methacrylate) (poly HEMA) hydro gel mixed with two kinds of selective fluorescent probes. Meso-2,6-Dichlorophenyltripyrrinone (TPN-Cl2) is used to react with zinc ion (Zn2+) and the synthesized "Chemosensor 1" is used to detect ferric ion (Fe3+). This hydro gel conjunction can serve as a light-guiding waveguide that allows light signals to transfer between two fibers. By using a multi-wavelength excitation light, a mixed solution that contains Zn2+ and Fe3+ can be detected in real-time. This miniaturized sensor develops an image for real-time monitoring of Zn2+ and Fe3+ ions in vivo. (C) 2016 Elsevier B.V. All rights reserved.
Hypochlorous acid turn-on boron dipyrromethene probe based on oxidation of methyl phenyl sulfide
(2013-10-24)
Liu, Shi-Rong
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Vedamalai, Mani
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Wu, Shu-Pao
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應用化學系
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Department of Applied Chemistry
A boron dipyrromethene (BODIPY)-based fluorometric probe, HCS, has been successfully developed for the highly sensitive and selective detection of hypochlorous acid (HOCl). The probe is based on the specific HOCl-promoted oxidation of methyl phenyl sulfide. The reaction is accompanied by a 160-fold increase in the fluorescent quantum yield (from 0.003 to 0.480). The fluorescent turn-on mechanism is accomplished by suppression of photoinduced electron transfer (PET) from the methyl phenyl sulfide group to BODIPY. The fluorescence intensity of the reaction between HOCl and HCS shows a good linearity in the HOCl concentration range 1-10 mu M. The detection limit is 23.7 nM (S/N = 3). In addition, confocal fluorescence microscopy imaging using RAW264.7 macrophages demonstrates that the HCS probe could be an efficient fluorescent detector for HOCl in living cells. (C) 2013 Published by Elsevier B.V.
Hypochlorous Acid Turn-on Fluorescent Probe Based on Oxidation of Diphenyl Selenide
(2013-02-15)
Liu, Shi-Rong
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Wu, Shu-Pao
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應用化學系
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Department of Applied Chemistry
A BODIPY-based fluorescent probe, HCSe, has been successfully developed for the rapid detection of hypochlorous acid based on the specific HOCl-promoted oxidation of diphenyl selenide in response to the amount of HOCl. Confocal fluorescence microscopy imaging using RAW264.7 cells showed that the new probe HCSe could be used as an effective fluorescent probe for detecting HOCl in living cells.
New water-soluble highly selective fluorescent chemosensor for Fe (III) ions and its application to living cell imaging
(2012-08-01)
Liu, Shi-Rong
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Wu, Shu-Pao
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應用化學系
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Department of Applied Chemistry
A new rhodamine-based chemosensor exhibits excellent selectivity for Fe3+ ions over a wide range of tested metal ions Ag+, Al3+, Ca2+, Cd2+, Co2+, Cr3+, Cu2+, Fe2+, Hg2+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+ in an aqueous solution. The binding of Fe3+ to chemosensor 1 produces an absorption band at 564 nm and an emission band at 588 nm because Fe3+-binding induces ring-opening of the spirolactam in 1. The binding ratio of the 1-Fe3+ complexes was determined to be 1:1 according to a Job plot. The association constant (K-a) of Fe3+ binding in chemosensor 1 was 6.9 x 10(3) M-1. The maximum fluorescence enhancement caused by Fe3+ binding in chemosensor 1 occurred at a pH range of 6-7.5. The fluorescence microscopy experiments in this study demonstrated that chemosensor 1 can be used as a fluorescent probe for detecting Fe3+- in living cells. (C) 2012 Elsevier B.V. All rights reserved.