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Basu A, Vaskevich A, Chuntonov L. Glutathione Self-Assembles into a Shell of Hydrogen-Bonded Intermolecular Aggregates on "Naked" Silver Nanoparticles. J Phys Chem B 2021; 125:895-906. [PMID: 33440116 DOI: 10.1021/acs.jpcb.0c10089] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A detailed understanding of the molecular structure in nanoparticle ligand capping layers is crucial for their efficient incorporation into modern scientific and technological applications. Peptide ligands render the nanoparticles as biocompatible materials. Glutathione, a γ-ECG tripeptide, self-assembles into aggregates on the surface of ligand-free silver nanoparticles through intermolecular hydrogen bonding and forms a few nanometer-thick shells. Two-dimensional nonlinear infrared (2DIR) spectroscopy suggests that aggregates adopt a conformation resembling the β-sheet secondary structure. The shell thickness was evaluated with localized surface plasmon resonance spectroscopy and X-ray photoelectron spectroscopy. The amount of glutathione on the surface was obtained with spectrophotometry of a thiol-reactive probe. Our results suggest that the shell consists of ∼15 stacked molecular layers. These values correspond to the inter-sheet distances, which are significantly shorter than those in amyloid fibrils with relatively bulky side chains, but are comparable to glycine-rich silk fibrils, where the side chains are compact. The tight packing of the glutathione layers can be facilitated by hydrogen-bonded carboxylic acid dimers of glycine and the intermolecular salt bridges between the zwitterionic γ-glutamyl groups. The structure of the glutathione aggregates was studied by 2DIR spectroscopy of the amide-I vibrational modes using 13C isotope labeling of the cysteine carbonyl. Isotope dilution experiments revealed the coupling of modes forming vibrational excitons along the cysteine chain. The coupling along the γ-glutamyl exciton chain was estimated from these values. The obtained coupling strengths are slightly lower than those of native β-sheets, yet they appear large enough to point onto an ordered conformation of the peptides within the aggregate. Analysis of the excitons' anharmonicities and the strength of the transition dipole moments generally is in agreement with these observations.
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Affiliation(s)
- Arghyadeep Basu
- Schulich Faculty of Chemistry and Solid State Institute, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Alexander Vaskevich
- Department of Materials and Interfaces, and Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Lev Chuntonov
- Schulich Faculty of Chemistry and Solid State Institute, Technion - Israel Institute of Technology, Haifa 3200003, Israel
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2
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Chakrabarty S, Maity S, Yazhini D, Ghosh A. Surface-Directed Disparity in Self-Assembled Structures of Small-Peptide l-Glutathione on Gold and Silver Nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:11255-11261. [PMID: 32880182 DOI: 10.1021/acs.langmuir.0c01527] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Despite the key roles of l-glutathiones (GSHs) inbiology and nano-biotechnology, understanding their labile structures and hydrogen bond interactions with nanoparticles has posed a critical challenge to the scientific community. The structural conformation of GSH as a capping layer on gold nanoparticle (AuNP) and silver nanoparticle (AgNP) surfaces is investigated. In this report, we attempt to explore the material-dependent interaction of GSH with different spherical nanoparticle surfaces by employing Fourier transform infrared (FTIR) spectroscopy. The infrared signal of amide I of GSH is studied as a function of different materials' spherical nanoparticles with comparable size. We revealed the β-sheet secondary structure of GSH on AgNPs and the random structure on AuNPs even though both the nanoparticles have comparable shapes and sizes and belong to the same group of the periodic table. The GSH is firmly anchored on the gold and silver surface via the thiol of the cys part. However, our experimental data designate a further interaction with the AgNP surface via the carboxylic acid group of the gly- and glu- end of the molecule. It is observed that enhancement of IR absorption of amide I of GSH is pronounced by a factor of 10 on AuNP but, in contrast, on the same-sized AgNP, the suppression is perceived by a factor of 2, even though both are plasmonic materials with respect to free GSH. This study can be used as a point of reference for understanding the structural conformation of the capping layer on nanoparticle surfaces as well as surface enhancement of the IR absorption of amide I. We would like to emphasize that molecular self-assembly on the nanoparticle surfaces is definitely of very broad interest for chemists working in nearly any subdiscipline, spanning from the nanoparticle-based medicine to surface-enhanced spectroscopy to heterogeneous catalysis, etc.
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Affiliation(s)
- Suranjana Chakrabarty
- Department of Condensed Matter Physics and Materials Sciences, S. N. Bose National Centre for Basic Sciences, JD Block, Sector-III, Salt Lake City, Kolkata 700106, India
| | - Swagata Maity
- Department of Condensed Matter Physics and Materials Sciences, S. N. Bose National Centre for Basic Sciences, JD Block, Sector-III, Salt Lake City, Kolkata 700106, India
| | - Darshana Yazhini
- Department of Condensed Matter Physics and Materials Sciences, S. N. Bose National Centre for Basic Sciences, JD Block, Sector-III, Salt Lake City, Kolkata 700106, India
| | - Anup Ghosh
- Department of Condensed Matter Physics and Materials Sciences, S. N. Bose National Centre for Basic Sciences, JD Block, Sector-III, Salt Lake City, Kolkata 700106, India
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3
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Ghosh A, Prasad AK, Chuntonov L. Two-Dimensional Infrared Spectroscopy Reveals Molecular Self-Assembly on the Surface of Silver Nanoparticles. J Phys Chem Lett 2019; 10:2481-2486. [PMID: 30978284 DOI: 10.1021/acs.jpclett.9b00530] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The conformation of molecules, peptides, and proteins, self-assembled into structured monolayers on the surface of metal nanoparticles (NPs), can strongly affect their properties and use in chemical or nanobiomedical applications. Elucidating molecular conformations on the NP surface is highly challenging, and the microscopic details mostly remain elusive. Using polarization-selective third-order two-dimensional ultrafast infrared spectroscopy, we revealed the highly ordered intermolecular structure of γ-tripeptide glutathione on the surface of silver NPs in aqueous solution. Glutathione is an antioxidant thiol abundant in living cells; it is extensively used in NP chemistry and related research. We identified conditions where the interaction of glutathione with the NP surface facilitates formation of a β-sheet-like structure enclosing the NPs. A spectroscopic signature associated with the assembly of β-sheets into an amyloid fibril-like structure was also observed. Remarkably, the interaction with the metal surface promotes formation of a fibril-like structure by a small peptide involving only two amino acids.
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Affiliation(s)
- Anup Ghosh
- Schulich Faculty of Chemistry and Solid State Institute , Technion - Israel Institute of Technology , Haifa 3200003 , Israel
| | - Amit K Prasad
- Schulich Faculty of Chemistry and Solid State Institute , Technion - Israel Institute of Technology , Haifa 3200003 , Israel
| | - Lev Chuntonov
- Schulich Faculty of Chemistry and Solid State Institute , Technion - Israel Institute of Technology , Haifa 3200003 , Israel
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4
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Liu Z, Liu Y, Kim E, Bentley WE, Payne GF. Electrochemical Probing through a Redox Capacitor To Acquire Chemical Information on Biothiols. Anal Chem 2016; 88:7213-21. [PMID: 27385047 PMCID: PMC4962791 DOI: 10.1021/acs.analchem.6b01394] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
![]()
The
acquisition of chemical information is a critical need for
medical diagnostics, food/environmental monitoring, and national security.
Here, we report an electrochemical information processing approach
that integrates (i) complex electrical inputs/outputs, (ii) mediators
to transduce the electrical I/O into redox signals that can actively
probe the chemical environment, and (iii) a redox capacitor that manipulates
signals for information extraction. We demonstrate the capabilities
of this chemical information processing strategy using biothiols because
of the emerging importance of these molecules in medicine and because
their distinct chemical properties allow evaluation of hypothesis-driven
information probing. We show that input sequences can be tailored
to probe for chemical information both qualitatively (step inputs
probe for thiol-specific signatures) and quantitatively. Specifically,
we observed picomolar limits of detection and linear responses to
concentrations over 5 orders of magnitude (1 pM–0.1 μM).
This approach allows the capabilities of signal processing to be extended
for rapid, robust, and on-site analysis of chemical information.
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Affiliation(s)
- Zhengchun Liu
- Department of Biomedical Engineering, School of Geosciences and Info-Physics, Central South University , Changsha 410083, People's Republic of China.,Institute for Bioscience and Biotechnology Research and Fischell Department of Bioengineering, University of Maryland , College Park, Maryland 20742, United States
| | - Yi Liu
- Institute for Bioscience and Biotechnology Research and Fischell Department of Bioengineering, University of Maryland , College Park, Maryland 20742, United States
| | - Eunkyoung Kim
- Institute for Bioscience and Biotechnology Research and Fischell Department of Bioengineering, University of Maryland , College Park, Maryland 20742, United States
| | - William E Bentley
- Institute for Bioscience and Biotechnology Research and Fischell Department of Bioengineering, University of Maryland , College Park, Maryland 20742, United States
| | - Gregory F Payne
- Institute for Bioscience and Biotechnology Research and Fischell Department of Bioengineering, University of Maryland , College Park, Maryland 20742, United States
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Calborean A, Martin F, Marconi D, Turcu R, Kacso I, Buimaga-Iarinca L, Graur F, Turcu I. Adsorption mechanisms of l-Glutathione on Au and controlled nano-patterning through Dip Pen Nanolithography. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 57:171-80. [DOI: 10.1016/j.msec.2015.07.042] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 06/29/2015] [Accepted: 07/22/2015] [Indexed: 11/16/2022]
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6
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Podešva P, Foret F. Metal nano-film resistivity chemical sensor. Electrophoresis 2015; 37:392-7. [DOI: 10.1002/elps.201500190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 05/13/2015] [Accepted: 05/13/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Pavel Podešva
- Institute of Analytical Chemistry AS CR, v.v.i; Brno Czech Republic
| | - František Foret
- Institute of Analytical Chemistry AS CR, v.v.i; Brno Czech Republic
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Liu Y, Li C, Liu Y, Tang Z. Helical silver(I)-glutathione biocoordination polymer nanofibres. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2013; 371:20120307. [PMID: 24000359 DOI: 10.1098/rsta.2012.0307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Helical nanofibres of silver(I)-glutathione (Ag-GSH) biocoordination polymer (BCP) are fabricated by introducing dimethyl sulfoxide into the mixture solution of Ag⁺ ions and L-GSH molecules. The prepared BCP nanofibres show hierarchical helical structures, which are constructed via twisting of small fibres. Water-soluble helices could be further cross-linked with Ca²⁺ ions to form a well-dispersed aqueous suspension. When gold nanorods are adsorbed onto these helical nanofibres, the unique plasmon-induced circular dichroism characteristic is observed in the region of the local surface plasmon resonance of gold nanorods. This type of chiroptical metamaterials may have promising applications in nonlinear optics, negative refraction and biosensing.
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Affiliation(s)
- Yong Liu
- National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
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8
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Aliakbar Tehrani Z, Jamshidi Z, Jebeli Javan M, Fattahi A. Interactions of Glutathione Tripeptide with Gold Cluster: Influence of Intramolecular Hydrogen Bond on Complexation Behavior. J Phys Chem A 2012; 116:4338-47. [DOI: 10.1021/jp2080226] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zahra Aliakbar Tehrani
- Department of Chemistry, Sharif
University of Technology, P .O. Box 11365-9516, Tehran, Iran
| | - Zahra Jamshidi
- Chemistry and Chemical Engineering
Research Center of Iran, P.O. Box 14335-186, Tehran, Iran
| | - Marjan Jebeli Javan
- Department of Chemistry, Sharif
University of Technology, P .O. Box 11365-9516, Tehran, Iran
| | - Alireza Fattahi
- Department of Chemistry, Sharif
University of Technology, P .O. Box 11365-9516, Tehran, Iran
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9
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Hepel M, Stobiecka M. Comparative kinetic model of fluorescence enhancement in selective binding of monochlorobimane to glutathione. J Photochem Photobiol A Chem 2011. [DOI: 10.1016/j.jphotochem.2011.09.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Drug–GSH interaction on GSH–Au modified electrodes: A cyclic voltammetry and electrochemical impedance spectroscopy study. J Electroanal Chem (Lausanne) 2011. [DOI: 10.1016/j.jelechem.2011.07.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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11
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Wang T, Bai Y, Luo H, Yan X, Zheng W. Electrochemical characteristic of Selenocysteine Self-assembly monolayers at Au electrode. J Electroanal Chem (Lausanne) 2011. [DOI: 10.1016/j.jelechem.2011.03.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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12
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Stobiecka M, Hepel M. Effect of buried potential barrier in label-less electrochemical immunodetection of glutathione and glutathione-capped gold nanoparticles. Biosens Bioelectron 2011; 26:3524-30. [PMID: 21371877 DOI: 10.1016/j.bios.2011.01.038] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 01/17/2011] [Accepted: 01/31/2011] [Indexed: 10/18/2022]
Abstract
The influence of potential barriers, introduced to the immunoglobulin-based sensory films, on voltammetric signals of a redox ion probe has been investigated. Films with positive and negative barriers have been examined by depositing charged self-assembled thiol monolayers as the basal layers of a sensory film. The studies performed with monoclonal anti-glutathione antibody-based sensors using ferricyanide ion probe have shown stronger sensor response to the layer components, as well as to the glutathione-capped gold nanoparticles acting as the antigen, for films with positive potential barrier buried deep in the film than for negative barrier films. The larger changes in differential resistance, peak separation and peak heights observed for films with positive barrier have been attributed to different depth and width of the charge distributions in these films. A buried positive barrier with narrow charge distribution width provides the best conditions for film stability and prevents fouling (less ion-exchanges with the medium). This conclusion has been confirmed by calculations of the electric field distribution and potential profiles in immunosensing films performed by numerical integration of Poisson equation for Gaussian distributions of fixed charges of covalently bound components. The proposed fixed-charge model can aid in rapid evaluation of sensory films in sensor development work. The implications of potential barriers in sensory film design are discussed.
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Affiliation(s)
- Magdalena Stobiecka
- Department of Chemistry, State University of New York at Potsdam, Potsdam, NY 13676, USA
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13
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Preda L, Negrila C, Lazarescu MF, Anastasescu M, Dobrescu G, Santos E, Lazarescu V. Hemin interaction with bare and 4,4′-thio-bis-benzene-thiolate covered n-GaAs (110) electrodes. Phys Chem Chem Phys 2011; 13:17104-14. [DOI: 10.1039/c1cp21652j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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14
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Liu Y, Ma W, Liu W, Li C, Liu Y, Jiang X, Tang Z. Silver(i)–glutathione biocoordination polymer hydrogel: effective antibacterial activity and improved cytocompatibility. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm13693c] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Stobiecka M, Coopersmith K, Hepel M. Resonance elastic light scattering (RELS) spectroscopy of fast non-Langmuirian ligand-exchange in glutathione-induced gold nanoparticle assembly. J Colloid Interface Sci 2010; 350:168-77. [DOI: 10.1016/j.jcis.2010.06.010] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 06/07/2010] [Accepted: 06/08/2010] [Indexed: 11/13/2022]
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16
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Ligand exchange effects in gold nanoparticle assembly induced by oxidative stress biomarkers: Homocysteine and cysteine. Biophys Chem 2010; 146:98-107. [DOI: 10.1016/j.bpc.2009.11.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2009] [Revised: 11/10/2009] [Accepted: 11/10/2009] [Indexed: 02/07/2023]
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17
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Hepel M, Dallas J. Multifunctional Polypeptide EQCN Sensors: Probing the Cysteamine-Glutathione Film Permeability with Hg(II) Ions. SENSORS 2008; 8:7224-7240. [PMID: 27873925 PMCID: PMC3787441 DOI: 10.3390/s8117224] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Revised: 11/10/2008] [Accepted: 11/13/2008] [Indexed: 11/16/2022]
Abstract
Multifunctional films are the basis of biosensors and play an important role in the emerging field of nanobioelectronics. In this work, films of a tripeptide glutathione (GSH) immobilized on a self-assembled monolayer of cysteamine (CA-SAM) on a quartz crystal Au piezosensor have been synthesized and characterized using electrochemical quartz crystal nanogravimetry (EQCN) with a Hg(II) ion probe. It has been found that in contrast to previously studied Au/GSH films, the Au/CA-GSH films strongly hinder the formation of Hg⁰ with bulk properties while still allowing for relatively easy permeation by Hg(II) ions. This results in complete disappearance of the sharp Hg⁰ electrodissolution peak which is observed on bare Au and Au/GSH piezosensors. The multiple-peak anodic behavior of Au/CA and bare Au is replaced by a single high-field anodic peak of mercury reoxidation in the case of Au/CA-GSH sensors. The mass-to-charge plots indicate predominant ingress/egress of Hg(II) to/from the film. The strong hindrance of CA-SAM to bulk-Hg⁰ formation is attributed to film-stabilizing formation of surface (CA)₂Hg2+ complexes with conformation evaluated by ab initio quantum mechanical calculations of electronic structure using Hartree-Fock methods. The associates CA-GSH provide an additional functionality of the side sulfhydryl group which is free for interactions, e.g. with heavy metals. It is proposed that in the film, the CA-GSH molecules can assume open (extended) conformation or bent hydrogen-bonded conformation with up to four possible internal hydrogen bonds.
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Affiliation(s)
- Maria Hepel
- Department of Chemistry, State University of New York at Potsdam, Potsdam, NY 13676, USA.
- Department of Chemistry, State University of New York at Buffalo, Buffalo, NY 14260, USA.
| | - Julia Dallas
- Department of Chemistry, State University of New York at Potsdam, Potsdam, NY 13676, USA
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18
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Interactions and reactivity of Hg(II) on glutathione modified gold electrode studied by EQCN technique. J Electroanal Chem (Lausanne) 2008. [DOI: 10.1016/j.jelechem.2008.05.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Lim IIS, Mott D, Ip W, Njoki PN, Pan Y, Zhou S, Zhong CJ. Interparticle interactions in glutathione mediated assembly of gold nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:8857-8863. [PMID: 18642936 DOI: 10.1021/la800970p] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The understanding of the detailed molecular interactions between (GSH) glutathione molecules in the assembly of metal nanoparticles is important for the exploitation of the biological reactivity. We report herein results of an investigation of the assembly of gold nanoparticles mediated by glutathione and the disassembly under controlled conditions. The interparticle interactions and reactivities were characterized by monitoring the evolution of the surface plasmon resonance band using the spectrophotometric method and the hydrodynamic sizes of the nanoparticle assemblies using the dynamic light scattering technique. The interparticle reactivity of glutathiones adsorbed on gold nanoparticles depends on the particle sizes and the ionic strength of the solution. Larger-sized particles were found to exhibit a higher degree of interparticle assembly than smaller-sized particles. The assembly-disassembly reversibility is shown to be highly dependent on pH and additives in the solution. The interactions of the negatively charged citrates surrounding the GSH monolayer on the particle surface were believed to produce more effective interparticle spatial and electrostatic isolation than the case of OH (-) groups surrounding the GSH monolayer. The results have provided new insights into the hydrogen-bonding character of the interparticle molecular interaction of glutathiones bound on gold nanoparticles. The fact that the interparticle hydrogen-bonding interactions in the assembly and disassembly processes can be finely tuned by pH and chemical means has implications to the exploitation of the glutathione-nanoparticle system in biological detection and biosensors.
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Affiliation(s)
- I-Im S Lim
- Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, USA
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Scendo M, Hepel M. Inhibiting properties of benzimidazole films for Cu(II)/Cu(I) reduction in chloride media studied by RDE and EQCN techniques. J Electroanal Chem (Lausanne) 2008. [DOI: 10.1016/j.jelechem.2007.10.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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21
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Bieri M, Gautier C, Bürgi T. Probing chiral interfaces by infrared spectroscopic methods. Phys Chem Chem Phys 2007; 9:671-85. [PMID: 17268678 DOI: 10.1039/b609930k] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biological homochirality on earth and its tremendous consequences for pharmaceutical science and technology has led to an ever increasing interest in the selective production, the resolution and the detection of enantiomers of a chiral compound. Chiral surfaces and interfaces that can distinguish between enantiomers play a key role in this respect as enantioselective catalysts as well as for separation purposes. Despite the impressive progress in these areas in the last decade, molecular-level understanding of the interactions that are at the origin of enantiodiscrimination are lagging behind due to the lack of powerful experimental techniques to spot these interactions selectively with high sensitivity. In this article, techniques based on infrared spectroscopy are highlighted that are able to selectively target the chiral properties of interfaces. In particular, these methods are the combination of Attenuated Total Reflection InfraRed (ATR-IR) with Modulation Excitation Spectroscopy (MES) to probe enantiodiscriminating interactions at chiral solid-liquid interfaces and Vibrational Circular Dichroism (VCD), which is used to probe the structure of chirally-modified metal nanoparticles. The former technique aims at suppressing signals arising from non-selective interactions, which may completely hide the signals of interest due to enantiodiscriminating interactions. Recently, this method was successfully applied to investigate enantiodiscrimination at self-assembled monolayers of chiral thiols on gold surfaces. The nanometer size analogues of the latter--gold nanoparticles protected by a monolayer of a chiral thiol--are amenable to VCD spectroscopy. It is shown that this technique yields detailed structural information on the adsorption mode and the conformation of the adsorbed thiol. This may also turn out to be useful to clarify how chirality can be bestowed onto the metal core itself and the nature of the chirality of the latter, which is manifested in the metal-based circular dichroism activity of these nanoparticles.
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Affiliation(s)
- Marco Bieri
- Université de Neuchâtel, Institut de Microtechnique, Laboratoire de Chimie Physique des Surfaces, Rue Emile-Argand 11, 2009, Neuchâtel, Switzerland
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22
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Hepel M, Stobiecka M. Interactions of adsorbed albumin with underpotentially deposited copper on gold piezoelectrodes. Bioelectrochemistry 2007; 70:155-64. [PMID: 16725378 DOI: 10.1016/j.bioelechem.2006.03.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Indexed: 11/16/2022]
Abstract
The adsorption of a model protein, bovine serum albumin (BSA), on Au electrodes was investigated using the Cu adatom probe method and Electrochemical Quartz Crystal Nanobalance (EQCN) technique. The adsorption of BSA was confirmed by AFM imaging and has been found to be controlled by kinetics. Using the Cu adatom probe method, we were able to reconstruct the entire BSA adsorption transient Theta(BSA) vs. t. The adsorption rate constant k(1), determined from this transient is k(1)=2.45x10(5) L mol(-1) s(-1). We have found that the bulk Cu(0) deposition process is blocked by BSA adsorption and it decays exponentially with time during BSA adsorption. It ceases completely when a full monolayer of BSA is formed. In contrast to that, the mass associated with Cu-u.p.d. decreases only to ca. 50% of that in the absence of BSA, indicating that Cu adatoms can penetrate (wedge) into the space between the surface Au atoms and the adsorbed BSA molecules. In addition to that, we have found that the degree of penetration of Cu adatoms can be controlled by the applied deposition potential. By selecting a sufficiently cathodic potential, we were able to deposit a full Cu-u.p.d. monolayer, independent of the BSA surface coverage extending from Theta(BSA)=0 to Theta(BSA) approximately 1. The positive shift of Cu(ad) desorption peak potential E(p), observed in the presence of adsorbed BSA, has been interpreted in terms of Frumkin exchange interaction forces between Cu(ad) and BSA(ad), on the basis of our earlier theoretical model, expanded here to include adsorbed species in two monolayers. This expansion is possible owing to the fast rate of Cu adatom penetration in the interfacial region. From the plots of E(p) vs. Theta(BSA), the presence of strong attractive interactions between Cu(ad) and BSA(ad) was deduced. These interactions result in a super-shift of the Cu-u.p.d. desorption peak potential, corresponding to the exchange interaction coefficient g(M,X)<-4, indicating on a possibility of the formation of a stable interface complex.
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Affiliation(s)
- Maria Hepel
- Department of Chemistry, State University of New York at Potsdam, Potsdam, NY 13676, USA.
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Su Y, Xie Q, Cao Z, Jia X, Yao S. EQCM and Fluoroelectrochemical Studies on the Catalytic Oxidation of NADH at a Pencil 8B-Scrawled Gold Electrode with High Detection Sensitivity. ELECTROANAL 2006. [DOI: 10.1002/elan.200603510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Bieri M, Bürgi T. Adsorption kinetics of l-glutathione on gold and structural changes during self-assembly: an in situATR-IR and QCM study. Phys Chem Chem Phys 2006; 8:513-20. [PMID: 16482294 DOI: 10.1039/b511146c] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The adsorption of L-glutathione (gamma-Glu-Cys-Gly) from ethanol on gold surfaces was studied in situ by both attenuated total reflection infrared (ATR-IR) spectroscopy and using a quartz crystal microbalance (QCM). The molecule is firmly anchored to the gold surface through the thiol group. Different IR signals of adsorbed L-glutathione, notably the amide I and nu(-COOH), show significantly different behavior with time, which reveals that their increase is not related to adsorption (mass uptake) alone. This indicates that structural transformations take place during the formation of the self-assembled monolayer (SAM). In particular, the intensity of the acid signal increases quickly only within the first couple of minutes. The complexity of the self-assembling process is confirmed by QCM measurements, which show fast mass uptake within about 100 s followed by a considerably slower regime. The structural change superimposed on the mass uptake is, based on the in situ time-resolved ATR-IR measurements, assigned to the interaction of the acid group of the Gly moiety with the surface. The latter group is protonated in ethanol but deprotonates upon interaction with the gold surface. The protonation-deprotonation equilibrium is sensitive to external stimuli, such as the presence of dissolved L-glutathione molecules. The interaction of the acid group with the surface and concomitant deprotonation proceeds via two distinguishable steps, the first being a reorientation of the molecule, followed by the deprotonation.
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Affiliation(s)
- Marco Bieri
- Université de Neuchâtel, Institut de Chimie, Rue Emile-Argand 11, 2007 Neuchâtel, Switzerland
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Bieri M, Bürgi T. Adsorption Kinetics, Orientation, and Self-Assembling of N-Acetyl-l-cysteine on Gold: A Combined ATR-IR, PM-IRRAS, and QCM Study. J Phys Chem B 2005; 109:22476-85. [PMID: 16853928 DOI: 10.1021/jp052409m] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The adsorption of N-acetyl-L-cysteine from ethanol solution on gold has been studied by in situ attenuated total reflection infrared (ATR-IR) spectroscopy, polarization modulation infrared reflection absorption spectroscopy, and a quartz crystal microbalance. After an initial fast adsorption, in situ ATR-IR revealed two considerably slower processes, besides further adsorption. The appearance of carboxylate bands and the partial disappearance of the carboxylic acid bands demonstrated that part of the molecules on the surface underwent deprotonation. In addition, the C=O stretching vibration of the carboxylic acid group shifted to lower and the amide II band to higher wavenumbers, indicating hydrogen-bonding interactions within the adsorbate layer. Based on the initial ATR-IR spectrum, which did not reveal deprotonation, the orientation of the molecule within the adsorbate layer was determined. For this, density functional theory was used to calculate the transition dipole moment vectors of the vibrational modes of N-acetyl-l-cysteine. The projections of the latter onto the z-axis of the fixed surface coordinate system were used to determine relative band intensities for different orientations of the molecule. The analysis revealed that the amide group is tilted with respect to and points away from the surface, whereas the carboxylic acid is in proximity to the surface, which is also supported by a shift of the C-O-H bending mode. This position of the acid group favors its deprotonation assisted by the gold surface and easily enables intermolecular interactions. Periodic acid stimuli revealed reversible protonation/deprotonation of part of the adsorbed molecules. However, only non-hydrogen-bonded carboxylic acid groups showed a response toward the acid stimuli.
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Affiliation(s)
- Marco Bieri
- Institut de Chimie, Université de Neuchâtel, Rue Emile-Argand 11, 2007- Neuchâtel, Switzerland
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Stobiecka M, Hepel M, Radecki J. Transient conformation changes of albumin adsorbed on gold piezoelectrodes. Electrochim Acta 2005. [DOI: 10.1016/j.electacta.2005.03.066] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Studying the binding of Cd2+ by ω-mercaptoalkanoic acid self assembled monolayers by cyclic voltammetry and scanning electrochemical microscopy (SECM). J Electroanal Chem (Lausanne) 2005. [DOI: 10.1016/j.jelechem.2005.05.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Bieri M, Bürgi T. Probing Enantiospecific Interactions between Proline and an l-Glutathione Self-Assembled Monolayer by Modulation Excitation ATR-IR Spectroscopy. J Phys Chem B 2005; 109:10243-50. [PMID: 16852241 DOI: 10.1021/jp050197n] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The interaction of proline with self-assembled monolayers (SAMs) of l-glutathione (gamma-glu-cys-gly) on gold was investigated by a combination of attenuated total reflection (ATR-IR) infrared and modulation excitation spectroscopy (MES). The latter technique makes use of phase-sensitive detection of periodically varying signals and allows discrimination between species with different kinetics such as dissolved proline and adsorbed molecules. By applying a convection-diffusion model coupled to adsorption and desorption, it was possible to extract relative adsorption and desorption rates from the experimental data for the two enantiomers of proline, fully accounting for mass transport within the flow-through cell. The results show that, in particular, the desorption kinetics is different for the two enantiomers. Therefore, the l-glutathione SAM can discriminate between enantiomers, d-proline being stronger bound. The IR spectra reveal that upon interaction with proline the adsorbed l-glutathione is protonated at the gly part of the molecule, which, in the absence of proline, is bound to the gold surface as carboxylate. The observed protonation of adsorbed l-glutathione upon interaction with proline goes along with a structural change of the former, which seems to play an important role for enantiodiscrimination.
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Affiliation(s)
- Marco Bieri
- Université de Neuchâtel, Institut de Chimie, Rue Emile-Argand 11, 2007- Neuchâtel, Switzerland
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Bieri M, Bürgi T. L-glutathione chemisorption on gold and acid/base induced structural changes: a PM-IRRAS and time-resolved in situ ATR-IR spectroscopic study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:1354-63. [PMID: 15697281 DOI: 10.1021/la047735s] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Adsorption of the tripeptide L-glutathione (gamma-glu-cys-gly) on gold surfaces was investigated by polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) and attenuated total reflection (ATR) infrared spectroscopy. PM-IRRAS was used to study ex situ the adsorbate layer prepared from aqueous solutions at different pH, whereas ATR-IR was applied to study in situ adsorption from ethanol in the presence and absence of acid and base. ATR-IR was furthermore combined with modulation spectroscopy in order to investigate the reversible changes within the adsorbate layer induced by acid and base stimuli, respectively. The molecule is firmly anchored on the gold surface via the thiol group of the cys part. However, the ATR-IR spectra in ethanol indicate a further interaction with the gold surface via the carboxylic acid group of the gly part of the molecule, which deprotonates upon adsorption. Hydrochloric acid readily protonates the two acid groups of the adsorbed molecule. During subsequent ethanol flow the acid groups deprotonate again, a process which proceeds in two distinct steps: a fast step associated with the deprotonation of the acid in the glu part of the molecule and a considerably slower step associated with deprotonation of the acid in the gly moiety. The latter process is assisted by the interaction of the corresponding acid group with the surface. The spectra furthermore indicate a rearrangement of the hydrogen bonding network within the adsorbate layer upon deprotonation. Depending on the protonation state during adsorption of l-glutathione, the response toward identical protonation-deprotonation stimuli is significantly different. This is explained by the ionic state-dependent shape of the molecule, as supported by density functional theory calculations. The different shapes of the individual molecules during layer formation thus influence the structure of the adsorbate layer.
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Affiliation(s)
- Marco Bieri
- Institut de Chimie, Faculté des Sciences, Université de Neuchâtel, Rue Emile-Argand 11, 2007 Neuchâtel, Switzerland
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Hepel M, Tewksbury E. Nanogravimetric study of templated copper deposition in ion-channels of self-assembled glutathione films on gold piezoelectrodes. Electrochim Acta 2004. [DOI: 10.1016/j.electacta.2004.01.088] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Inzelt G, Puskás Z. Adsorption and precipitation during the redox transformations of phenazine. Electrochim Acta 2004. [DOI: 10.1016/j.electacta.2003.12.027] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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