101
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Hvasanov D, Mason AF, Goldstein DC, Bhadbhade M, Thordarson P. Optimising the synthesis, polymer membrane encapsulation and photoreduction performance of Ru(II)- and Ir(III)-bis(terpyridine) cytochrome c bioconjugates. Org Biomol Chem 2013; 11:4602-12. [PMID: 23715338 DOI: 10.1039/c3ob40620b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ruthenium(II) and iridium(III) bis(terpyridine) complexes were prepared with maleimide functionalities in order to site-specifically modify yeast iso-1 cytochrome c possessing a single cysteine residue available for modification (CYS102). Single X-ray crystal structures were solved for aniline and maleimide Ru(II) 3 and Ru(II) 4, respectively, providing detailed structural detail of the complexes. Light-activated bioconjugates prepared from Ru(II) 4 in the presence of tris(2-carboxyethyl)-phosphine (TCEP) significantly improved yields from 6% to 27%. Photoinduced electron transfer studies of Ru(II)-cyt c in bulk solution and polymer membrane encapsulated specimens were performed using EDTA as a sacrificial electron donor. It was found that membrane encapsulation of Ru(II)-cyt c in PS140-b-PAA48 resulted in a quantum efficiency of 1.1 ± 0.3 × 10(-3), which was a two-fold increase relative to the bulk. Moreover, Ir(III)-cyt c bioconjugates showed a quantum efficiency of 3.8 ± 1.9 × 10(-1), equivalent to a ∼640-fold increase relative to bulk Ru(II)-cyt c.
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102
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Yepuri NR, Jamieson SA, Darwish TA, Rawal A, Hook JM, Thordarson P, Holden PJ, James M. Synthesis of per-deuterated alkyl amines for the preparation of deuterated organic pyromellitamide gelators. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.03.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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103
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Hvasanov D, Peterson JR, Thordarson P. Self-assembled light-driven photosynthetic-respiratory electron transport chain hybrid proton pump. Chem Sci 2013. [DOI: 10.1039/c3sc51780b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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104
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Lowe AJ, Pfeffer FM, Thordarson P. Determining binding constants from 1H NMR titration data using global and local methods: a case study using [n]polynorbornane-based anion hosts. Supramol Chem 2012. [DOI: 10.1080/10610278.2012.688972] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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105
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Chen X, Luais E, Darwish N, Ciampi S, Thordarson P, Gooding JJ. Studies on the effect of solvents on self-assembled monolayers formed from organophosphonic acids on indium tin oxide. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:9487-9495. [PMID: 22621243 DOI: 10.1021/la3010129] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The preparation of self-assembled monolayers (SAMs) of organophosphonic acids on indium tin oxide (ITO) surfaces from different solvents (triethylamine, ethyl ether, tetrahydofuran (THF), pyridine, acetone, methanol, acetonitrile, dimethyl sulfoxide (DMSO), or water) has been performed with some significant differences observed. Cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and contact angle measurement demonstrated that the quality of SAMs depends critically on the choice of solvents. Higher density, more stable monolayers were formed from solvents with low dielectric constants and weak interactions with the ITO. It was concluded low dielectric solvents that were inert to the ITO gave monolayers that were more stable with a higher density of surface bound molecules because higher dielectric constant solvents and solvents that coordinate with the surface disrupted SAM formation.
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106
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Prasad S, Bhadbhade M, Thordarson P. Tin(IV) porphyrin functionalization of electrochemically active fluoride-doped tin-oxide (FTO) via Huisgen [3+2] click chemistry. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424611002970] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A novel tetra-alkyne terminated tin(IV) porphyrin 3 was synthesized in good yields and characterized using NMR spectroscopy, high resolution mass spectrometry and X-ray crystallography, the latter revealing interactions with hexane molecules that stabilize the crystal structure of the tin(IV) porphyrin 3. It was then linked to a conductive fluorine-doped tin oxide (FTO) surfaces using Huisgen [3+2] click chemistry. The attachment of the tin(IV) porphyrin to the FTO surface 6 was characterized by X-ray photoelectron spectroscopy (XPS), indicating the presence of the 1,2,3-triazole unit. Electrochemical measurements of the tin(IV) porphyrin modified FTO surface 7 show that it is still electrochemically active with oxidation (Epa) and reduction peaks (Epc) for the ferricyanide redox couple observed at Epc and Epa of -0.144 and +0.568 V vs. Ag | AgCl respectively, representing a modest shift of ca . +/- 0.1–0.15 V, compared to unmodified FTO.
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107
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Olijve LLC, How ENW, Bhadbhade M, Prasad S, Colbran SB, Zhao C, Thordarson P. Structural, electrochemical and photochemical investigation of the water-soluble tin(IV) tetrakis(2-N-hydroxyethyl-4-pyridinium)porphyrin photocatalyst. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424611004312] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The water-soluble tin(IV) tetrakis(2-N-hydroxyethyl-4-pyridinium)porphyrin 1 photocatalyst was synthesized in good yield and its structure determined by single crystal X-ray crystallography. Electrochemical measurements on tin(IV) porphyrin 1 reveal a range of complex redox processes that are highly dependent on the pH and electrode used. The cathodic processes at ca. -0.6 to -0.8 V were assigned to electrochemical processes on the pyridyl moiety following differential pulse voltammetry and spectroelectrochemical investigation into the electrochemical properties of tin(IV) porphyrin. Photocatalytic experiment on tin(IV) porphyrin 1 under anaerobic conditions using triethanolamine (TEAO) as a sacrifical donor reveal a phlorin species as the main product which rapidly disappears upon exposure to oxygen. These results suggest that tin(IV) porphyrin π-radical anion is perhaps not the species responsible for the apparent ability tin(IV) porphyrins to photocatalytically reduce various substrates, including water to hydrogen.
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108
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109
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Kobayashi K, Cheng D, Huynh M, Ratinac KR, Thordarson P, Braet F. Imaging fluorescently labeled complexes by means of multidimensional correlative light and transmission electron microscopy: practical considerations. Methods Cell Biol 2012; 111:1-20. [PMID: 22857920 DOI: 10.1016/b978-0-12-416026-2.00001-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
These days the common ground between structural biology and molecular biology continues to grow thanks to the biomolecular insights offered by correlative microscopy, even though the vision of combining insights from different imaging tools has been around for nearly four decades. The use of correlative imaging methods to dissect the cell's internal structure is progressing faster than ever as shown by the boom in the number of methodological approaches available for correlative microscopy studies, each designed to address a specific scientific question. In this chapter, we will present a relatively straightforward approach to combining information from fluorescence microscopy and electron microscopy at the supramolecular level. The method combines live-cell and/or confocal laser microscopy with classical sample preparation for transmission electron microscopy (TEM), thereby allowing the integration of dynamic details of subcellular processes with insights about the organelles and molecular machinery involved. We illustrate the applicability of this multidimensional correlative microscopy approach on cultured Caco-2 colorectal cancer cells exposed to fluorescently labeled cisplatin, and discuss how these methods can deepen our understanding of key cellular processes, such as drug uptake and cell fate.
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110
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Howe ENW, Bhadbhade M, Thordarson P. Highly Sheared Anti-Parallel Dipolar Carbonyl···Carbonyl Interaction in the Crystal Packing of Strapped Crown-3-Pyromellitimide. Aust J Chem 2012. [DOI: 10.1071/ch12085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Non-covalent dipolar interactions between pairs of carbonyls have been demonstrated to play a significant role in the crystal packing and formation of supramolecular structural architecture of small organic molecules. Under high dilution, the strapped crown-3-pyromellitimide 4 and macrocyclic crown-6-bispyromellitimide 5 were synthesised in concert and demonstrated selective molecular recognition towards Na+ and K+, respectively. The molecular structure of strapped crown-3-pyromellitimide 4 was solved using X-ray crystallography and an unusual highly sheared anti-parallel dipolar carbonyl···carbonyl interaction was observed in the crystal packing. The intermolecular interaction has a torsion angle of 44.1°, and deviates from the three idealised motifs reported in literature. This finding further highlights the importance and versatility of dipolar carbonyl···carbonyl interaction in the crystal packing of organic molecules.
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111
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Mulholland AR, Thordarson P, Mensforth EJ, Langford SJ. Porphyrin dyads linked by a rotatable 3,3′-biphenyl scaffold: a new binding motif for small ditopic molecules. Org Biomol Chem 2012; 10:6045-53. [DOI: 10.1039/c2ob25147g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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112
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Wu YN, Chen DH, Shi XY, Lian CC, Wang TY, Yeh CS, Ratinac KR, Thordarson P, Braet F, Shieh DB. Cancer-cell-specific cytotoxicity of non-oxidized iron elements in iron core-gold shell NPs. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2011; 7:420-7. [DOI: 10.1016/j.nano.2011.01.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 12/14/2010] [Accepted: 01/03/2011] [Indexed: 11/28/2022]
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113
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Wu YN, Yang LX, Shi XY, Li IC, Biazik JM, Ratinac KR, Chen DH, Thordarson P, Shieh DB, Braet F. The selective growth inhibition of oral cancer by iron core-gold shell nanoparticles through mitochondria-mediated autophagy. Biomaterials 2011; 32:4565-73. [DOI: 10.1016/j.biomaterials.2011.03.006] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 03/04/2011] [Indexed: 12/29/2022]
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114
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Ratinac KR, Yang W, Gooding JJ, Thordarson P, Braet F. Graphene and Related Materials in Electrochemical Sensing. ELECTROANAL 2011. [DOI: 10.1002/elan.201000545] [Citation(s) in RCA: 231] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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115
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Goldstein DC, Cheng YY, Schmidt TW, Bhadbhade M, Thordarson P. Photophysical properties of a new series of water soluble iridium bisterpyridine complexes functionalised at the 4' position. Dalton Trans 2011; 40:2053-61. [PMID: 21218240 DOI: 10.1039/c0dt01317j] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Four new hetero- and homo-leptic iridium(III) bisterpyridine complexes have been prepared which incorporate aniline (tpy-φ-NH(2)), benzoic acid (tpy-φ-COOH), and benzyl alcohol (tpy-φ-CH(2)OH) substituents at the 4' positions of the tpy ligands (tpy = 2,2':6',2''-terpyridine, φ = phenylene). The electrochemical behaviour and ground and excited state spectroscopic properties of the complexes are reported, and the X-ray crystal structures of a homoleptic benzyl alcohol [Ir(tpy-φ-CH(2)OH)(2)](PF(6))(3), homoleptic aniline [Ir(tpy-φ-NH(2))(2)](PF(6))(3), and heteroleptic benzyl alcohol/aniline substituted complex [Ir(tpy-φ-CH(2)OH)(tpy-φ-NH(2))](PF(6))(3) have been solved. Complexes with aniline substituents were found to display absorption bands at around 430 nm corresponding to intraligand charge transfer (ILCT) that are sensitive to changes in solvent and pH. Strong emission in the visible region involving the ILCT state is observed in two of the complexes (Φ(e) = 0.7% and 2.6%) in acetonitrile. In the heteroleptic aniline/benzyl alcohol complex the Stokes shift is shown to be linearly related to solvent polarisability according to the Lippert equation, but only for solvents with weak hydrogen bonding interactions. Additionally, in water, emission from the ILCT state is quenched and only weak ligand centred (LC) emission is observed. The long lifetimes and quantum yields of these complexes make them interesting candidates for probes in sensing applications, especially [Ir(tpy-φ-CH(2)OH)(tpy-φ-NH(2))(2)](PF(6))(3) due to its unusual sensitivity to the solvent environment.
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116
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Truong WT, Su Y, Meijer JT, Thordarson P, Braet F. Cover Picture: Self-Assembled Gels for Biomedical Applications (Chem. Asian J. 1/2011). Chem Asian J 2011. [DOI: 10.1002/asia.201090045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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117
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Dehn S, Tong KWK, Clady RGC, Owen DM, Gaus K, Schmidt TW, Braet F, Thordarson P. The structure and luminescence properties of europium(iii) triflate doped self-assembled pyromellitamide gels. NEW J CHEM 2011. [DOI: 10.1039/c1nj20085b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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118
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Hvasanov D, Wiedenmann J, Braet F, Thordarson P. Induced polymersome formation from a diblock PS-b-PAA polymer via encapsulation of positively charged proteins and peptides. Chem Commun (Camb) 2011; 47:6314-6. [DOI: 10.1039/c1cc11662b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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119
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Jones SL, Wong KH, Thordarson P, Ladouceur F. Self-assembling electroactive hydrogels for flexible display technology. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:494105. [PMID: 21406771 DOI: 10.1088/0953-8984/22/49/494105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have assessed the potential of self-assembling hydrogels for use in conformal displays. The self-assembling process can be used to alter the transparency of the material to all visible light due to scattering by fibres. The reversible transition is shown to be of low energy by differential scanning calorimetry. For use in technology it is imperative that this transition is controlled electrically. We have thus synthesized novel self-assembling hydrogelator molecules which contain an electroactive group. The well-known redox couple of anthraquinone/anthrahydroquinone has been used as the hydrophobic component for a series of small molecule gelators. They are further functionalized with peptide combinations of L-phenylalanine and glycine to provide the hydrophilic group to complete 'head-tail' models of self-assembling gels. The gelation and electroactive characteristics of the series were assessed. Cyclic voltammetry shows the reversible redox cycle to be only superficially altered by functionalization. Additionally, spectroelectrochemical measurements show a reversible transparency and colour change induced by the redox process.
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120
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Thordarson P. Determining association constants from titration experiments in supramolecular chemistry. Chem Soc Rev 2010; 40:1305-23. [PMID: 21125111 DOI: 10.1039/c0cs00062k] [Citation(s) in RCA: 1525] [Impact Index Per Article: 108.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The most common approach for quantifying interactions in supramolecular chemistry is a titration of the guest to solution of the host, noting the changes in some physical property through NMR, UV-Vis, fluorescence or other techniques. Despite the apparent simplicity of this approach, there are several issues that need to be carefully addressed to ensure that the final results are reliable. This includes the use of non-linear rather than linear regression methods, careful choice of stoichiometric binding model, the choice of method (e.g., NMR vs. UV-Vis) and concentration of host, the application of advanced data analysis methods such as global analysis and finally the estimation of uncertainties and confidence intervals for the results obtained. This tutorial review will give a systematic overview of all these issues-highlighting some of the key messages herein with simulated data analysis examples.
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121
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Truong WT, Su Y, Meijer JT, Thordarson P, Braet F. Self-Assembled Gels for Biomedical Applications. Chem Asian J 2010; 6:30-42. [DOI: 10.1002/asia.201000592] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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122
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Yang W, Ratinac KR, Ringer SP, Thordarson P, Gooding JJ, Braet F. ChemInform Abstract: Carbon Nanomaterials in Biosensors: Should You Use Nanotubes or Graphene? ACTA ACUST UNITED AC 2010. [DOI: 10.1002/chin.201024271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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123
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Yang W, Ratinac K, Ringer S, Thordarson P, Gooding J, Braet F. Kohlenstoffnanomaterialien für Biosensoren: Nanoröhren oder Graphen - was eignet sich besser? Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.200903463] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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124
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Yang W, Ratinac K, Ringer S, Thordarson P, Gooding J, Braet F. Carbon Nanomaterials in Biosensors: Should You Use Nanotubes or Graphene? Angew Chem Int Ed Engl 2010; 49:2114-38. [DOI: 10.1002/anie.200903463] [Citation(s) in RCA: 1192] [Impact Index Per Article: 85.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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125
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Peterson JR, Smith TA, Thordarson P. Synthesis and room temperature photo-induced electron transfer in biologically active bis(terpyridine)ruthenium(II)-cytochrome c bioconjugates and the effect of solvents on the bioconjugation of cytochrome c. Org Biomol Chem 2009; 8:151-62. [PMID: 20024146 DOI: 10.1039/b919289a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photo-active bis(terpyridine)ruthenium(ii) chromophores were synthesised and attached to the redox enzyme iso-1 cytochrome c in a mixed solvent system to form photo-induced bioconjugates in greater than 40% yield after purification. The effects of up to 20% (v/v) of acetonitrile, tetrahydrofuran, dimethylformamide, or dimethyl sulfoxide at 4, 25 and 35 degrees C on the stability and biological activity of cytochrome c and its reactivity towards the model compound 4,4'-dithiodipyridine (DTDP) was measured. The second-order rate constant for the DTDP reaction was found to range between k = 2.5-4.3 M(-1) s(-1) for reactions with 5% organic solvent added compared to k = 5.6 M(-1) s(-1) in pure water at 25 degrees C. Use of 20% solvent generally results in significant protein oxidation, and 20% acetonitrile and tetrahydrofuran in particular result in significant protein dimerization, which competes with the bioconjugation reaction. Cyclic voltammetry studies indicated that the rate of electron transfer to the heme in solution was reduced in the bis(terpyridine)ruthenium(ii) cytochrome c bioconjugates compared to unmodified cytochrome c. Steady-state fluorescence studies on these bioconjugates showed that energy or electron transfer is taking place between the bis(terpyridine)ruthenium(ii) chromophores and cytochrome c. The bis(terpyridine)ruthenium(ii) cytochrome c bioconjugates demonstrate room temperature photo-activated electron transfer from the bis(terpyridine)ruthenium(ii) donor to the protein acceptor. Two sacrificial donors were used; in 50% glycerol, the bioconjugates were reduced in about 15 min while in 20 mM EDTA the bioconjugates were fully reduced in less than 5 min upon irradiation with a xenon lamp source. Under these conditions, the reduction of the non-covalent mixture of cytochrome c and bis(terpyridine)ruthenium(ii) mixtures took over 30 min. Control experiments showed that the photo-induced reduction of cytochrome c only occurs in the absence of oxygen and presence of a sacrificial donor. These results are encouraging for future incorporation of these bioconjugates in light-responsive bioelectronic circuits, including photo-activated biosensors and biofuel cells.
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