City University of Hong Kong
DSpace
 

CityU Institutional Repository >
3_CityU Electronic Theses and Dissertations >
ETD - Dept. of Biology and Chemistry  >
BCH - Doctor of Philosophy  >

Please use this identifier to cite or link to this item: http://hdl.handle.net/2031/4887

Title: New biological labels and probes derived from luminescent and redox-active organometallic compounds
Other Titles: Ju fa guang xing ji yang hua huan yuan huo xing de jin shu you ji hua he wu yan sheng chu de xin sheng wu biao ji shi ji ji tan ce qi
具發光性及氧化還原活性的金屬有機化合物衍生出的新生物標記試劑及探測器
Authors: Lau, Shing Yip (柳成業)
Department: Dept. of Biology and Chemistry
Degree: Doctor of Philosophy
Issue Date: 2007
Publisher: City University of Hong Kong
Subjects: Organometallic compounds
Notes: CityU Call Number: QD411.L38 2007
Includes bibliographical references (leaves 385-405)
Thesis (Ph.D.)--City University of Hong Kong, 2007
xv, 405 leaves : ill. ; 30 cm.
Type: Thesis
Abstract: A series of luminescent cyclometalated iridium(III) arylbenzothiazole biotin complexes, [Ir(N-C)2L](PF6) (N-CH = 2-phenylbenzothiazole, Hbt; 2-((1,1’-biphenyl)-4-yl)benzothiazole, Hbsb; 2-(2-thienyl)benzothiazole, Hbtth; 2-(1-naphthyl)benzothiazole, Hbsn; L = 4-(N-((6-biotinamido)hexyl)amido)-4’-methyl-2,2’-bipyridine) has been synthesized and characterized. Their photophysical and electrochemical properties have been investigated. Upon photoexcitation, these complexes displayed intense and long-lived luminescence in fluid solutions at 298 K and in alcohol glass at 77 K. The emission is derived from a 3IL ( *) (N-C–) excited state, probably with some mixing of 3MLCT (d(Ir) *(N-C–)) character. The avidin-binding properties of these complexes have been investigated by luminescence titrations and competitive assays. Upon binding to avidin, these complexes showed significant emission enhancement and lifetime extension. On the basis of these observations, homogeneous competitive assays for biotin have been studied. Four luminescent cyclometalated iridium(III) diimine complexes [Ir(N-C)2(N-N)](PF6) (N-CH = 2-(4-(N-((2-biotinamido)ethyl)aminomethyl)phenyl)pyridine, 2-(4-(N-((6-biotinamido)hexyl)aminomethyl)phenyl)pyridine; N-N = 3,4,7,8-tetramethyl-1,10-phenanthroline, Me4-phen; 4,7-diphenyl-1,10-phenanthroline, Ph2-phen), each containing two biotin units, have been synthesized, characterized, and their photophysical and electrochemical properties have been investigated. Photoexcitation of these iridium(III) diimine bis(biotin) complexes in fluid solutions at 298 K and in alcohol glass at 77 K resulted in intense and long-lived luminescence. The emission is assigned to a 3MLCT (d(Ir) *(N-N)) excited state. The emissive states of the Me4-phen complexes are probably mixed with some 3IL ( *) (Me4-phen) character. The interactions of these iridium(III) diimine bis(biotin) complexes with avidin have been studied by 4’-hydroxyazobenzene-2-carboxylic acid (HABA) assays and emission titrations. The potential of these complexes to act as cross-linkers for avidin has been examined by resonance-energy transfer (RET)-based emission quenching experiments, microscopy studies using avidin-conjugated microspheres, and HPLC analysis. The synthesis, characterization, and electrochemical and photophysical properties of a series of luminescent rhenium(I) thiourea complexes [Re(Me4-phen)(CO)3(Py-An)](CF3SO3) and [Re(Me4-phen)(CO)3(Py-Ph)](CF3SO3) (Me4-phen = 3,4,7,8-tetramethyl-1,10-phenanthroline; Py-An = N-(1-anthraquinonyl)-N’-(4-pyridinylmethyl)thiourea; Py-Ph = N-(1-phenyl)-N’-(4-pyridinylmethyl)thiourea)) and a control compound N-(1-anthraquinonyl)-N’-ethylthiourea (Et-An) have been investigated. The X-ray crystal structure of [Re(Me4-phen)(CO)3(Py-Ph)] (CF3SO3) has been studied. Upon photoexcitation, the rhenium(I) thiourea complexes displayed intense and long-lived green luminescence in fluid solutions at 298 K and in alcohol glass at 77 K. The emission is assigned to a 3MLCT (d(Re) *(N-N)) excited state. The anion-binding properties of these complexes have been studied by electronic absorption and emission titrations. The luminescent iridium(III) thiourea complexes [Ir(N-C)2(N-N)](PF6) (N-CH = 2-phenylpyridine, Hppy; 7,8-benzoquinoline, Hbzq; 2-phenylquinoline, Hpq; N-N = phen-TU-Et; phen-TU-Ph; phen-TU-MeA) have been synthesized and characterized. The photophysical and electrochemical properties of these complexes have been investigated. Upon excitation, all the complexes displayed intense and long-lived green to orange luminescence under ambient conditions and in low-temperature alcohol glass. The emission of the complexes has been assigned to a 3MLCT (d(Ir) *(N-N)) excited state. The binding of OAc–, F–, and H2PO4– to the complexes has been investigated by emission titrations. The ferrocene thiol compound Fc-C6-SH has been synthesized, characterized, and its electrochemical properties studied. Since the sulfhydryl group of this compound can undergo a facile addition reaction with the ,-unsaturated carbonyl group, this compound has been used as a redox-active label for a derivative of microcystins, microcystin-LR (MC-LR). The conjugate, Fc-MC-LR, has been isolated by HPLC with electrochemical detection. The peak height-concentration curve was linear in the test range 20 – 400 ng of MC-LR (r value for linear regression > 0.9987). The detection limit was determined to be ca. 18 ng MC-LR (S/N = 3). The purified conjugate displayed a reversible ferrocenium/ferrocene couple at ca. –0.04 V vs SCE in 0.1 M aqueous ammonium acetate–acetonitrile (55:45 v/v). The synthesis, characterization, X-ray crystal structure, and electrochemical properties of a new redox-active biological labeling reagent N-(ferrocenyl)-iodoacetamide (Fc-IAA) are reported. This compound exhibited a reversible ferrocenium/ferrocene couple at ca. +0.35 V vs SCE in CH3CN at 298 K, and two irreversible reduction waves at ca. –1.32 and –2.05 V, attributable to the reduction of the iodoacetamide group. Since the iodoacetamide moiety can react specifically with the sulfhydryl group, Fc-IAA has been employed as a label for various biomolecules including a sulfhydryl-modified oligonucleotide, cysteine, glutathione, and sulfhydryl-modified bovine serum albumin. The electrochemical properties of the bioconjugates have been investigated by cyclic voltammetry. The synthesis, characterization, and electrochemical properties of three redox-active ferrocene indole compounds, N-(ferrocenylmethylenyl)tryptamine (Fc1), N-(ferrocenylmethyl)tryptamine (Fc2) and indole-3-(N-(6-(N-ferrocenylmethyl)aminohexyl))carboxamide (Fc3) are described. The X-ray crystal structures of Fc1 and Fc2 have been investigated. The recognition of the redox-active compounds Fc2 and Fc3 by indole-binding proteins including bovine serum albumin and tryptophanase has been studied by electrochemical and luminescence titrations and enzyme inhibition assays.
Online Catalog Link: http://lib.cityu.edu.hk/record=b2218117
Appears in Collections:BCH - Doctor of Philosophy

Files in This Item:

File Description SizeFormat
fulltext.html158 BHTMLView/Open
abstract.html158 BHTMLView/Open

Items in CityU IR are protected by copyright, with all rights reserved, unless otherwise indicated.

 

Valid XHTML 1.0!
DSpace Software © 2013 CityU Library - Send feedback to Library Systems
Privacy Policy · Copyright · Disclaimer