Browsing by Author "Venkatesan, Parthiban"

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A coumarin-based fluorescent probe for thiols and its application in cell imaging
(2016-09)
Liao, Yu-Cheng
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Venkatesan, Parthiban
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Wei, Ling-Fang
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Wu, Shu-Pao
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應用化學系
A new coumarin-based fluorescent probe CAA containing an acrylamide group has been designed and synthesized for the detection of biothiols. The probe CAA shows high selectivity and sensitivity for cysteine (Cys), homocysteine (Hcy), and glutathione (GSH) over other amino acids. A fluorescence turn-on response is induced by a Michael-type reaction. It shows a highly sensitive fluorescence emission to Cys, Hcy, and GSH, with detection limits of 192 nM for Cys, 158 nM for Hcy, and 155 nM for GSH (S/N = 3). Furthermore, confocal fluorescence microscopy imaging using RAW264.7 macrophages demonstrates that CAA can be an effective fluorescent probe for thiols in living cells. (C) 2016 Elsevier B.V. All rights reserved.
A fluorescent turn-on probe for detection of hypochlorus acid and its bioimaging in living cells
(2020-06-05)
Chu, Chien-Ju
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Wu, Guan-Syuan
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Ma, Ho-I
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Venkatesan, Parthiban
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Thirumalaivasan, Natesan
Hypochlorous acid has played several functions in the biological system. However, excess HOCI can cause damage to biomolecules and result in some diseases. Accordingly, a new fluorescent probe, BSP, has been developed for fast recognition of HOCI through the HOG-induced oxidation of methyl phenyl sulfide to sulfoxide. The reaction of BSP with HOG caused a 22-fold fluorescence enhancement (quantum yield increase from 0.006 to 0.133). The detection limit of HOCI is found to be 30 nM (S/N = 3). The fluorescence enhancement is due to the suppression of the photo-induced electron transfer from the methyl phenyl sulfide moiety to BODIPY. Eventually, the cellular fluorescence imaging experiment showed that BSP could be effectively used for monitoring HOCI in living cells. (C) 2020 Elsevier B.V. All rights reserved.
A highly fluorescent zinc complex of a dipodal N-acyl hydrazone as a selective sensor for H2PO4- ions and application in living cells
(2015-01-01)
Suganya, Sivalingam
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Velmathi, Sivan
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Venkatesan, Parthiban
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Wu, Shu-Pao
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Boobalan, Maria Susai
A dipodal N-acyl hydrazone receptor (R1) was synthesized in a single step, and utilized as a test probe for the selective sensing of metal ions as well as anions. Upon the exposure to various metal ions, R1 displays rapid colorimetric and absorption changes in the presence of Co2+, Ni2+, Cu2+ and Zn2+ ions. However, R1 shows a selective fluorescence response only in the presence of Zn2+ ions and no other metal ions showed obvious changes. In particular, zinc acetate showed higher sensitivity over other zinc sources. Upon the binding of Zn2+ ions with R1, the colorless solution changed into fluorescent yellow color accompanied by the conversion of the non-fluorescence nature into the highly fluorescence nature. The in situ formed R1-Zn2+ complex was further explored for the reversible recognition of H2PO4- ions selectively over other anions such as F-, Cl-, Br-, AcO-, CN-, HSO4- and NO3- ions. A strong and enhanced emission at 502 nm and 534 nm corresponding to the R1-Zn2+ complex was quenched completely in the presence of H2PO4- ions. Relay recognition of different phosphates such as mono, di and tri basic phosphate ions was also tested. Furthermore, R1 has good cell permeability and could serve as a bioprobe in living cells for the intracellular uptake of Zn2+ and H2PO4- ions. Time dependent density functional (TDDFT) calculation has been performed to demonstrate the binding of Zn2+ ions with R1.
A highly selective fluorescent sensor for Hg(II) based on an NTe2 chelating motif and its application to living cell imaging
(2015-01-01)
Kao, Shao-Lun
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Venkatesan, Parthiban
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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 fluorescent probe (NBDTe) based on an NTe2 chelating motif has been developed for the highly selective and sensitive detection of Hg2+. Significant fluorescence enhancement was observed with the chemosensor NBDTe in the presence of Hg2+. Moreover, the metal ions Ag+, Al3+, Ca2+, Cd2+, Co2+, Cu2+, Cr3+, Fe2+, Fe3+, Hg2+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+ produced only minor changes in the fluorescence values of the system. The association constant (K-a) of Hg2+ binding to the chemosensor NBDTe was found to be 3.81 x 10(3) M (1), with a detection limit of 4.2 mu M. The maximum fluorescence enhancement caused by Hg2+ binding to the chemosensor NBDTe was observed over the pH range of 4.0-10.0. In addition, fluorescence microscopy experiments showed that the chemosensor NBDTe can be used as a fluorescent probe for detecting Hg2+ in living cells.
A highly selective turn-on fluorescent probe for hypochlorous acid based on hypochlorous acid-induced oxidative intramolecular cyclization of boron dipyrromethene-hydrazone
(2015-07-02)
Chen, Wei-Chieh
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Venkatesan, Parthiban
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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, HBP, was developed for the detection of hypochlorous acid based on the specific hypochlorous acid-promoted oxidative intramolecular cyclization of heterocyclic hydrazone in response to the amount of HOCl. The reaction is accompanied by a 41-fold increase in the fluorescent quantum yield (from 0.004 to 0.164). The fluorescence intensity of the reaction between HOCl and HBP is linear in the HOCl concentration range of 1-8 mu M with a detection limit of 2.4 nM (S/N = 3). Confocal fluorescence microscopy imaging using RAW264.7 cells showed that the new probe HBP could be used as an effective fluorescent probe for detecting HOCl in living cells. (C) 2015 Elsevier B.V. All rights reserved.
A highly selective turn-on fluorescent sensor for fluoride and its application in imaging of living cells
(2014-12-01)
Yeh, Jiun-Ting
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Venkatesan, Parthiban
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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 fluorescent probe (FS) based on a fluoride-specific desilylation reaction has been developed for a highly selective and sensitive detection of F-. In the presence of F-, the probe FS provided significant green fluorescence enhancement, while other anions produced only minor changes in fluorescence intensity. The probe FS has a limit of detection of 1.45 mu M, which is reasonable for the detection of micromolar concentrations of F- ions. The maximum fluorescence enhancement induced by F- in the probe was observed over the pH range 7-10. Moreover, fluorescence microscopy imaging using mouse leukaemic monocyte macrophage showed that the probe FS could be an efficient fluorescent probe for F- ions in living cells.
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
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Wu, Shu-Pao
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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.
A rhodamine-based chemosensor with diphenylselenium for highly selective fluorescence turn-on detection of Hg2+ in vitro and in vivo
(2017-01-01)
Venkatesan, Parthiban
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Thirumalivasan, Natesan
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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 rhodamine-B based chemosensor with diphenylselenium, RhoSe, has been synthesized, and its detection behavior towards various metal ions is studied via UV/Vis and fluorescence spectroscopy. RhoSe shows a selective response to Hg2+ in CH3OH/H2O (v/v = 9 : 1) solutions over other metal ions. After addition of Hg2+, the solution of RhoSe displays an obvious color change from colorless to pink and a significant, 48-fold fluorescence enhancement. The color change and fluorescence enhancement are attributed to the ring-opening of the spirolactam in the rhodamine fluorophore, which is induced by Hg2+ binding. The binding ratio of RhoSe-Hg2+ was determined by a Job plot as a 1 : 1 ratio, and the effective pH range for Hg2+ detection was 4.0-10. Importantly, the reversibility of the RhoSe-Hg2+ complex was observed through the addition of Na2S. For practical applications, the strip method was utilized to detect Hg2+ in water/methanol solution. In addition, confocal fluorescence microscopy experiments demonstrated that RhoSe is an effective fluorescent probe for Hg2+ detection in vitro and in vivo.
A sensitive and selective fluorescent sensor for Zinc(II) and its application to living cell imaging
(2014-11-01)
Liu, Hao-Ming
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Venkatesan, Parthiban
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Wu, Shu-Pao
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交大名義發表
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應用化學系
A new dipyrromethene derivative (DPI) exhibits an enhanced fluorescence in the presence of Zn2+ ions and a high selectivity for Zn2+ ions over competing metal ions in methanol; Ag+, Ca2+, Co2+, Cr3+, Fe2+, Fe3+, Hg2+, Mg2+, Mn2+, Ni2+, and Pb2+ produced only minor changes in the fluorescence of DPI. The binding ratio of the DPI-Zn2+ complexes was determined from a Job plot to be 1:1. The binding constant (K-a) of Zn2+ binding to DPI was found to be 6.12 x 10(4) M-1, with a detection limit of 0.236 mu M. Fluorescence microscopy imaging using RAW264.7 cells showed that DPI could be used as an effective fluorescent probe for detecting Zn2+ in living cells. (C) 2014 Elsevier B.V. All rights reserved.
A triple action chemosensor for Cu2+ by chromogenic, Cr3+ by fluorogenic and CN- by relay recognition methods with bio-imaging of HeLa cells
(2017-09-01)
Vijay, Natarajan
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Balamurugan, Gopal
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Venkatesan, Parthiban
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Wu, Shu Pao
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Velmathi, Sivan
A triple action chemosensor (R1) bearing a rhodamine and thiophene moiety was synthesized by a simple condensation reaction. The sensing behaviour and selectivity of the synthesized chemosensor toward metal ions were studied by UV-Vis and fluorescence spectroscopy. The chemosensor recognized Cu2+ and Cr3+ ions with significant changes in UV-Vis absorbance and fluorescence intensity. The results showed that Cr3+ induced greater fluorescence enhancement whereas Cu2+ ions bound strongly with the receptor by showing a strong absorption band at 554 nm but with weak fluorescence. A visible colour change was observed by the addition of Cu2+ and that colour change is due to the opening of the spirolactam ring triggered by the addition of Cu2+ ions. Job's plot analysis indicated a 1 : 2 and 1 : 1 binding stoichiometry between the chemosensor and Cr3+/Cu2+. Subsequently, the R1 - Cu2+ complex chemosensor was employed to detect CN- in the presence of different anions, such as F-, Cl-, Br-, I-, AcO-, H2PO4-, HSO4-, NO3- and -OH. In addition, the live cell imaging of HeLa cells using R1 and Cr3+ was demonstrated successfully.
A turn-on fluorescent probe for hypochlorous acid based on HOCl-promoted removal of the C=N bond in BODIPY-hydrazone
(2015-01-01)
Chen, Wei-Chieh
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Venkatesan, Parthiban
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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-based fluorescent probe, BODH, has been successfully developed for hypochlorous acid detection based on the HOCl-promoted oxidative removal of the C=N bond in response to the amount of HOCl. The reaction is accompanied by a 6-fold increase in fluorescent quantum yield (from 0.05 to 0.29). The fluorescence intensity of the reaction between HOCl and BODH shows a good linearity in the HOCl concentration range of 1-25 mu M with a low detection limit of 205 nM (S/N = 3). Confocal fluorescence microscopy imaging using RAW264.7 cells shows that the new probe, BODH, can be used as an effective fluorescent probe for the detection of HOCl in living cells.
A turn-on fluorescent probe for hypochlorous acid based on the oxidation of diphenyl telluride
(2015-01-01)
Venkatesan, Parthiban
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Wu, Shu-Pao
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交大名義發表
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National Chiao Tung University
A fluorescent probe HCTe was developed for rapid detection of hypochlorous acid based on the specific HOCl-promoted oxidation of diphenyl telluride. The reaction is accompanied by an 82-fold increase in the fluorescence quantum yield (from 0.009 to 0.75). The fluorescence turn-on mechanism is achieved by the suppression of photoinduced electron transfer (PET) from the diphenyl telluride group to BODIPY. The fluorescence intensity of the reaction between HOCl and HCTe is linear in the HOCl concentration range of 1 to 10 mu M with a detection limit of 41.3 nM (S/N = 3). In addition, confocal fluorescence microscopy imaging using RAW264.7 macrophages demonstrated that HCTe could be an efficient fluorescent probe for HOCl detection in living cells.
A turn-on fluorescent pyrene-based chemosensor for Cu(II) with live cell application
(2015-01-01)
Venkatesan, Parthiban
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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 pyrene-based fluorescent sensor (PHP) was synthesized for Cu(II) detection. It had high selectivity towards Cu2+ ions via photoinduced electron transfer (PET) based fluorescence enhancement. In the presence of Cu2+, PHP provided significant blue emission, while Ag+, Al3+, Ca2+, Cd2+, Co2+, Cr3+, Fe2+, Fe3+, Hg2+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+ metal ions produced only minor changes in the fluorescence spectra. The association constant (K-a) for Cu2+ binding to PHP had a value of 1.0 x 10(4) M-1. The maximum emission change induced by Cu2+ binding to the chemosensor PHP was observed over the pH range 5.0-10.0. Confocal fluorescence microscopy imaging using RAW264.7 cells showed that PHP can be used as an effective fluorescent probe for detecting Cu2+ in living cells.
An NAD(P)H: quinone oxidoreductase 1 (NQO1) enzyme responsive nanocarrier based on mesoporous silica nanoparticles for tumor targeted drug delivery in vitro and in vivo
(2016)
Gayam, Srivardhan Reddy
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Venkatesan, Parthiban
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Sung, Yi-Ming
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Sung, Shuo-Yuan
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Hu, Shang-Hsiu
The synthesis and characterization of an NAD(P)H: quinone oxidoreductase 1 (NQO1) enzyme responsive nanocarrier based on mesoporous silica nanoparticles (MSNPs) for on-command delivery applications has been described in this paper. Gatekeeping of MSNPs is achieved by the integration of mechanically interlocked rotaxane nanovalves on the surface of MSNPs. The rotaxane nanovalve system is composed of a linear stalk anchoring on the surface of MSNPs, an alpha-cyclodextrin ring that encircles it and locks the payload "cargo" molecules in the mesopores, and a benzoquinone stopper incorporated at the end of the stalk. The gate opening and controlled release of the cargo are triggered by cleavage of the benzoquinone stopper using an endogenous NQO1 enzyme. In addition to having efficient drug loading and controlled release mechanisms, this smart biocompatible carrier system showed obvious uptake and consequent release of the drug in tumor cells, could selectively induce the tumor cell death and enhance the capability of inhibition of tumor growth in vivo. The controlled drug delivery system demonstrated its use as a potential theranostic material.
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
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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.
Colorimetric detection of chromium(III) using O-phospho-L-serine dithiocarbamic acid functionalized gold nanoparticles
(2015-12-01)
Lo, Shu-Hua
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Wu, Ming-Chun
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Venkatesan, Parthiban
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Wu, Shu-Pao
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應用化學系
A sensitive and selective colorimetric Cr3+ detection method was developed by using O-phospho-L-serine dithiocarbamic acid (PSDTC) functionalized gold nanoparticles (PSDTC-AuNPs). The presence of Cr3+ immediately induced aggregation of PSDTC-AuNPs, yielding a color change from red to blue. This Cr3+-induced aggregation of PSDTC-AuNPs was monitored by bare eye and UV-vis spectroscopy. The SPR absorbance (651 nm) of the reaction between PSDTC-AuNPs and Cr3+ shows a good linearity in the Cr3+ concentration with a low detection limit 4.2 nM (S/N = 3). PSDTC-AuNPs showed excellent selectivity toward Cr3+ compared to other metal ions Ag+, Al3+, Ca2+, Cd2+, Co2+, Cu2+, Fe2+, Fe3+, Hg2+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+. Optimal detection of Cr3+ was achieved over a pH range from 5 to 10. In addition, PSDTC-AuNPs were applied to detect Cr3+ in lake water, showing low interference. (C) 2015 Elsevier B.V. All rights reserved.
Colorimetric detection of Cu(II): Cu(II)-induced deprotonation of NH responsible for color change
(2014-12-01)
Kao, Shao-Lun
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Lin, Wan-Ying
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Venkatesan, Parthiban
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Wu, Shu-Pao
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應用化學系
Chemosensor 1 detects only the presence of Cu2+ ions among other metal ions through a color change from pale yellow to green. 1 functions as a tridentate ligand that binds Cu2+ ions through three amine nitrogen functional groups. In the presence of Cu2+, 1 provided significant color change, while Ag+, Ca2+, Cd2+, Co2+, Fe2+, Fe3+, Hg2+, Mn2+, Ni2+, Pb2+, and Zn2+ metal ions produced only minor changes in UV-vis absorption. The association constant (Ka) for Cu2+ binding to 1 had a value of 1.307 x 10(3) M-1. The maximum absorption change induced by Cu2+ binding to the chemosensor was observed over the pH range 6.0-10.0. A new band observed at 600 nm indicated the formation of deprotonated 1-Cu2+ complexes. C) 2014 Elsevier B.V. All rights reserved.
Cysteamine-modified diamond nanoparticles applied in cellular imaging and Hg2+ ions detection
(2019-01-28)
Shellaiah, Muthaiah
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Simon, Turibius
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Venkatesan, Parthiban
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Sun, Kien Wen
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Ko, Fu-Hsiang
Luminescent cysteamine-modified nanodiamond particles (ND-Cys) have been reported in surface-mediated energy transfer, cell imaging, and metal-ion recognition studies. In normalized photoluminescence (PL) spectral studies, the emission maxima of ND-Cys (at 50 mu g/mL in water) was fixed at 438 nm at 350 nm excitation, producing a blue emission with a quantum yield (Phi) of 0.13. In the dispersion range of 0-800 mu g/mL, ND-Cys exhibited agglomeration-induced energy transfer via red shifting of the PL peak from 438 nm to 451 nm. Analogous to PL studies, Raman interrogations also established the agglomeration and fixed the saturation limit to 500 mu g/mL in water. The low toxicity and biocompatibility of ND-Cys were demonstrated using methyl thiazolyl tetrazolium assay and time-dependent HeLa cell imaging. Subsequently, the Hg2+ selectivity by ND-Cys was revealed by an intense fluorescence peak shift from 440 nm to 463 nm. Fluorescence studies indicated that the detection limit of Hg2+ ions approximated 153 nM. Fourier-transform infrared and X-ray photoelectron spectroscopy (XPS) analyses supported the binding between free thiol (-SH) and amide (-C=O and -NH) groups of ND-Cys to Hg2+. The Hg2+-induced agglomeration and surface graphitization were successfully confirmed by X-ray powder diffraction, XPS, Raman, scanning electron microscopy, transmission electron microscopy, dynamic light scattering, and zeta potential analyses. Effective detection of Hg2+ ions by ND-Cys was validated through HeLa cell imaging at shortened time intervals.
Gd2O3:RE3+ and GdAIO(3):RE3+ (RE = Eu, Dy) Phosphor: Synthesis, Characterization and Bioimaging Application
(2017-02-01)
Selvalakshmi, Thangaraj
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Venkatesan, Parthiban
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Wu, Shu-Pao
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Velmathi, S.
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Bose, A. Chandra
Citrate based sol-gel method is used to synthesize Gd2O3:RE3+ and GdAlO3: RE3+ (RE = Eu, Dy) phosphors. In the present work, the phosphors are characterized using the techniques like X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). Fluorescence confocal microscopy reveals the potential usage of phosphors in biological medium for biolabeling application. XRD patterns confirm the phase purity of Gd2O3 and GdAlO3. The crystallite size and lattice parameters are estimated from XRD result. FTIR spectra are used to investigate the functional group present in the phosphor. The optical emission properties imply that the emission peak positions on Eu3+ or Dy3+ ion are size and host independent. Finally, RAW 264.7 macrophages cell line is used to test the bioimaging performance of the phosphors.
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.