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Perumal S, Atchudan R, Rühl E, Graf C. Controlled Synthesis of Platinum and Silver Nanoparticles Using Multivalent Ligands. NANOMATERIALS 2022; 12:nano12132294. [PMID: 35808130 PMCID: PMC9268602 DOI: 10.3390/nano12132294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 06/29/2022] [Accepted: 06/29/2022] [Indexed: 02/06/2023]
Abstract
Here, the controlled formation of platinum nanoparticles (PtNPs) and silver nanoparticles (AgNPs) using amine-functionalized multivalent ligands are reported. The effects of reaction temperature and ligand multivalency on the growth kinetics, size, and shape of PtNPs and AgNPs were systematically studied by performing a stepwise and a one-step process. PtNPs and AgNPs were prepared in the presence of amine ligands using platinum (II) acetylacetonate and silver (I) acetylacetonate, respectively. The effects of ligands and temperature on the formation of PtNPs were studied using a transmission electron microscope (TEM). For the characterization of AgNPs, additionally, ultraviolet-visible (UV-Vis) absorption was employed. The TEM measurements revealed that PtNPs prepared at different temperatures (160–200 °C, in a stepwise process) are monodispersed and of spherical shape regardless of the ligand multivalency or reaction temperature. In the preparation of PtNPs by the one-step process, ligands affect the shape of the PtNPs, which can be explained by the affinity of the ligands. The TEM and UV-Vis absorption studies on the formation of AgNPs with mono-, di-, and trivalent ligands showed narrower size distributions, while increasing the temperature from 80 °C to 120 °C and with a trivalent ligand in a one-step process.
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Affiliation(s)
- Suguna Perumal
- Physikalische Chemie, Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany;
- Department of Chemistry, Sejong University, Seoul 143747, Korea
| | - Raji Atchudan
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Korea;
| | - Eckart Rühl
- Physikalische Chemie, Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany;
- Correspondence: (E.R.); (C.G.)
| | - Christina Graf
- Physikalische Chemie, Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany;
- Department of Chemistry and Biotechnology, Darmstadt University of Applied Sciences, 64295 Darmstadt, Germany
- Correspondence: (E.R.); (C.G.)
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Sindram J, Karg M. Polymer ligand binding to surface-immobilized gold nanoparticles: a fluorescence-based study on the adsorption kinetics. SOFT MATTER 2021; 17:7487-7497. [PMID: 34323887 DOI: 10.1039/d1sm00892g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We report on a simple, fluorescence-based method for the investigation of the binding kinetics of polystyrene ligands, dispersed in an organic solvent, to substrate supported gold nanoparticles. For this purpose, we develop a protocol for the immobilization of gold nanoparticles on glass substrates, that yields sub-monolayers of randomly distributed particles with excellent homogeneity and reproducibility. Using fluorescently labeled polystyrene, we monitor the ligand concentration in bulk dispersion in real time and follow the binding to the particle-decorated substrates. The influence of the ligand molecular weight on the binding kinetics is investigated. We correlate the reaction rates with the diffusion coefficients of the different ligands and are able to describe the molecular weight dependency with a simple kinetic model. Both the diffusion and the activation step appear to contribute to the effective reaction rates.
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Affiliation(s)
- Julian Sindram
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
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Gong X, Taszarek M, Schefzig L, Reissig HU, Thierbach S, Wassermann B, Graf C, Mollenhauer D, Rühl E. Adsorption of Mono- and Divalent 4-(Dimethylamino)pyridines on Gold Surfaces: Studies by Surface-Enhanced Raman Scattering and Density Functional Theory. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:8667-8680. [PMID: 31173693 DOI: 10.1021/acs.langmuir.9b00371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The adsorption thermodynamics of 4-(dimethylamino)pyridine (DMAP) and its five divalent derivatives di-DMAP- n (2 ≤ n ≤ 6) with gradually increasing methylene-spacer lengths n binding to planar gold surfaces has been studied by surface-enhanced Raman spectroscopy (SERS) and density functional theory (DFT). SERS intensities of the totally symmetrical breathing mode of the pyridine ring at approximately 1007 cm-1 are used to monitor the surface coverage of the DMAP and di-DMAP- n ligands on gold surfaces at different concentrations. The equilibrium constant as a measure of the binding affinity is obtained from these measurements by using a modified Langmuir isotherm. Due to multivalent binding to the gold substrate, a characteristic enhancement of the binding affinity of di-DMAP- n compared to the monovalent DMAP is observed for all divalent species. First principles calculations of the di-DMAP- n ligands on an ideal Au(111) surface model as well as step terrace models have been performed to understand the adsorption structures and the multivalent binding enhancements. Furthermore, Raman spectra of the adsorbed molecules have been studied by first principles calculations to correlate the binding affinities to experimentally determined adsorption constants. The joint experimental and theoretical investigation of an oscillatory behavior of the binding affinity as a function of the methylene-spacer length in mono- and divalent 4-(dimethylamino)pyridines reveals that the molecular architecture plays an important role for the structure-function interplay of multivalently bound adsorbates.
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Affiliation(s)
- Xin Gong
- Physikalische Chemie , Institut für Chemie und Biochemie, Freie Universität Berlin , Arnimallee 22 , 14195 Berlin , Germany
| | - Maurice Taszarek
- Organische Chemie , Institut für Chemie und Biochemie, Freie Universität Berlin , Takustrasse 3 , 14195 Berlin , Germany
| | - Luise Schefzig
- Organische Chemie , Institut für Chemie und Biochemie, Freie Universität Berlin , Takustrasse 3 , 14195 Berlin , Germany
| | - Hans-Ulrich Reissig
- Organische Chemie , Institut für Chemie und Biochemie, Freie Universität Berlin , Takustrasse 3 , 14195 Berlin , Germany
| | - Steffen Thierbach
- Physikalische Chemie , Institut für Chemie und Biochemie, Freie Universität Berlin , Arnimallee 22 , 14195 Berlin , Germany
| | - Bernhard Wassermann
- Physikalische Chemie , Institut für Chemie und Biochemie, Freie Universität Berlin , Arnimallee 22 , 14195 Berlin , Germany
| | - Christina Graf
- Fachbereich Chemie- und Biotechnologie, Hochschule Darmstadt , Stephanstrasse 7 , 64295 Darmstadt , Germany
| | - Doreen Mollenhauer
- Physikalisch-Chemisches Institut , Justus-Liebig-Universität Gießen , Heinrich-Buff-Ring 17 , 35392 Gießen , Germany
- Center for Materials Research (LaMa) , Justus Liebig University Giessen , 35392 Gießen , Germany
| | - Eckart Rühl
- Physikalische Chemie , Institut für Chemie und Biochemie, Freie Universität Berlin , Arnimallee 22 , 14195 Berlin , Germany
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Salassa G, Sels A, Mancin F, Bürgi T. Dynamic Nature of Thiolate Monolayer in Au 25(SR) 18 Nanoclusters. ACS NANO 2017; 11:12609-12614. [PMID: 29166559 DOI: 10.1021/acsnano.7b06999] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Thiolate monolayer, protecting a gold nanocluster, is responsible for its chemical behavior and interaction with the environment. Understanding the parameters that influence the stability and reactivity of the monolayer will enable its precise and controlled functionalization. Here we present a protocol for the investigation of the monolayer reactivity in Au25(SR)18 based on MALDI mass spectrometry and NMR spectroscopy. Thiol exchange reaction between cluster and thiol molecules has been investigated showing how this reaction is affected by several factors (stability of the thiols in solution, the affinity of the sulfur to the gold cluster, intermolecular interactions within the ligand layer, etc.). Furthermore, intercluster thiol exchange has been clarified to occur during collisions between particles without thiol release to the solution. In this reaction, the stability of the thiols in solution and the affinity of the sulfur to the gold for the two thiols do not affect the equilibrium position because for both thiols one S-Au bond is broken and one is formed within the cycle. Importantly, the rate of direct thiol exchange between clusters is comparable to that of the ligand exchange with free thiols. However, the thermodynamic driving force of the two reactions is different, since only the latter involves free thiol species.
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Affiliation(s)
- Giovanni Salassa
- Department of Physical Chemistry, University of Geneva , 30 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Annelies Sels
- Department of Physical Chemistry, University of Geneva , 30 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Fabrizio Mancin
- Dipartimento di Scienze Chimiche, Università di Padova , via Marzolo 1, 35122 Padova, Italy
| | - Thomas Bürgi
- Department of Physical Chemistry, University of Geneva , 30 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
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Amiens C, Ciuculescu-Pradines D, Philippot K. Controlled metal nanostructures: Fertile ground for coordination chemists. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2015.07.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Ruff J, Steitz J, Buchkremer A, Noyong M, Hartmann H, Besmehn A, Simon U. Multivalency of PEG-thiol ligands affects the stability of NIR-absorbing hollow gold nanospheres and gold nanorods. J Mater Chem B 2016; 4:2828-2841. [DOI: 10.1039/c6tb00674d] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In this work the effect of multivalency on the stability of NIR-absorbing HAuNSs and AuNRs functionalized by mono-, bi- and tridentate polyethyleneglycol (PEG) thiol ligands is reported.
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Affiliation(s)
- J. Ruff
- Institute of Inorganic Chemistry
- RWTH Aachen University
- Aachen
- Germany
| | - J. Steitz
- Institute for Laboratory Animal Science
- University Hospital of the RWTH Aachen University
- Aachen
- Germany
| | - A. Buchkremer
- Institute of Inorganic Chemistry
- RWTH Aachen University
- Aachen
- Germany
| | - M. Noyong
- Institute of Inorganic Chemistry
- RWTH Aachen University
- Aachen
- Germany
| | - H. Hartmann
- Central Institute for Engineering
- Electronics and Analytics (ZEA-3)
- Jülich
- Germany
| | - A. Besmehn
- Central Institute for Engineering
- Electronics and Analytics (ZEA-3)
- Jülich
- Germany
| | - U. Simon
- Institute of Inorganic Chemistry
- RWTH Aachen University
- Aachen
- Germany
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8
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Merg AD, Slocik J, Blaber MG, Schatz GC, Naik R, Rosi NL. Adjusting the Metrics of 1-D Helical Gold Nanoparticle Superstructures Using Multivalent Peptide Conjugates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:9492-9501. [PMID: 26262910 DOI: 10.1021/acs.langmuir.5b02208] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The properties of nanoparticle superstructures depend on many factors, including the structural metrics of the nanoparticle superstructure (particle diameter, interparticle distances, etc.). Here, we introduce a family of gold-binding peptide conjugate molecules that can direct nanoparticle assembly, and we describe how these molecules can be systematically modified to adjust the structural metrics of linear double-helical nanoparticle superstructures. Twelve new peptide conjugates are prepared via linking a gold-binding peptide, AYSSGAPPMPPF (PEP(Au)), to a hydrophobic aliphatic tail. The peptide conjugates have 1, 2, or 3 PEP(Au) headgroups and a C12, C14, C16, or C18 aliphatic tail. The soft assembly of these peptide conjugates was studied using transmission electron microscopy (TEM), atomic force microscopy (AFM), and infrared (IR) spectroscopy. Several peptide conjugates assemble into 1-D twisted fibers having measurable structural parameters such as fiber width, thickness, and pitch that can be systematically varied by adjusting the aliphatic tail length and number of peptide headgroups. The linear soft assemblies serve as structural scaffolds for arranging gold nanoparticles into double-helical superstructures, which are examined via TEM. The pitch and interparticle distances of the gold nanoparticle double helices correspond to the underlying metrics of the peptide conjugate soft assemblies, illustrating that designed peptide conjugate molecules can be used to not only direct the assembly of gold nanoparticles but also control the metrics of the assembled structure.
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Affiliation(s)
- Andrea D Merg
- Department of Chemistry, University of Pittsburgh , 219 Parkman Ave., Pittsburgh, Pennsylvania 15260, United States
| | - Joseph Slocik
- Materials and Manufacturing Directorate, Air Force Research Laboratory , Wright-Patterson AFB, Ohio 45433, United States
| | - Martin G Blaber
- Department of Chemistry, Northwestern University , Evanston, Illinois 60208-3113, United States
| | - George C Schatz
- Department of Chemistry, Northwestern University , Evanston, Illinois 60208-3113, United States
| | - Rajesh Naik
- Materials and Manufacturing Directorate, Air Force Research Laboratory , Wright-Patterson AFB, Ohio 45433, United States
| | - Nathaniel L Rosi
- Department of Chemistry, University of Pittsburgh , 219 Parkman Ave., Pittsburgh, Pennsylvania 15260, United States
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9
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Mi Y, Liang P, Yang Z, Wang D, He W, Cao H, Yang H. Synthesis and co-assembly of gold nanoparticles functionalized by a pyrene–thiol derivative. RSC Adv 2015. [DOI: 10.1039/c4ra11932k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We synthesized a series of gold nanoparticles capped with 11-(4-(pyren-1-yl)phenoxy)undecane-1-thiol and with 1-dodecanethiol. The homodispersed gold nanoparticles were fully verified and co-assembly of gold nanoparticles composited with discotic molecules were investigated.
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Affiliation(s)
- Yongsheng Mi
- Department of Materials Physics and Chemistry
- School of Materials Science and Engineering
- University of Science and Technology Beijing
- Beijing 100083
- People's Republic of China
| | - Pengxia Liang
- Department of Materials Physics and Chemistry
- School of Materials Science and Engineering
- University of Science and Technology Beijing
- Beijing 100083
- People's Republic of China
| | - Zhou Yang
- Department of Materials Physics and Chemistry
- School of Materials Science and Engineering
- University of Science and Technology Beijing
- Beijing 100083
- People's Republic of China
| | - Dong Wang
- Department of Materials Physics and Chemistry
- School of Materials Science and Engineering
- University of Science and Technology Beijing
- Beijing 100083
- People's Republic of China
| | - Wanli He
- Department of Materials Physics and Chemistry
- School of Materials Science and Engineering
- University of Science and Technology Beijing
- Beijing 100083
- People's Republic of China
| | - Hui Cao
- Department of Materials Physics and Chemistry
- School of Materials Science and Engineering
- University of Science and Technology Beijing
- Beijing 100083
- People's Republic of China
| | - Huai Yang
- Department of Materials Science and Engineering
- College of Engineering
- Peking University
- Beijing 100871
- People's Republic of China
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10
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Thai T, Zheng Y, Ng SH, Ohshima H, Altissimo M, Bach U. Facile gold nanorod purification by fractionated precipitation. NANOSCALE 2014; 6:6515-6520. [PMID: 24838055 DOI: 10.1039/c4nr01592d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
An efficient and facile size- and shape-selective separation of gold nanorod (GNR) solutions is developed using a fractionated precipitation strategy. This convenient method has the benefit of eliminating nanoparticulate side products that can substantially deteriorate the quality of self-assembled nanostructures. The fabrication of advanced plasmonic metamaterials crucially depends on the capacity to supply feedstocks of high-purity building blocks.
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Affiliation(s)
- T Thai
- Department of Materials Engineering, Monash University, Wellington Road, Clayton, Victoria 3800, Australia.
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11
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Fertitta E, Voloshina E, Paulus B. Adsorption of multivalent alkylthiols on Au(111) surface: Insights from DFT. J Comput Chem 2013; 35:204-13. [DOI: 10.1002/jcc.23484] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 10/01/2013] [Accepted: 10/04/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Edoardo Fertitta
- Institut für Chemie und Biochemie-Physikalische und Theoretische Chemie; Freie Universität Berlin; Takustr. 3 D-14195 Berlin Germany
| | - Elena Voloshina
- Institut für Chemie; Humboldt Universitt zu Berlin; Brook-Taylor-Str. 2 D-12489 Berlin Germany
| | - Beate Paulus
- Institut für Chemie und Biochemie-Physikalische und Theoretische Chemie; Freie Universität Berlin; Takustr. 3 D-14195 Berlin Germany
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12
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Zopes D, Stein B, Mathur S, Graf C. Improved stability of "naked" gold nanoparticles enabled by in situ coating with mono and multivalent thiol PEG ligands. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:11217-11226. [PMID: 23906521 DOI: 10.1021/la4012058] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Unprotected ("naked") gold nanoparticles with high monodispersity ([d], 5.5± 0.5 nm) were obtained in a facile and single-step microwave-assisted hydrolytic decomposition of the molecular precursor [NMe4][Au(CF3)2]. Given their chloride-free surface chemistry, the as-obtained gold nanoparticles were in situ functionalized with mono-, di-, and trivalent thiolated PEG ligands in order to study the influence of multivalent character of the ligands on the stability of the colloidal solutions. For this purpose, a novel tridentate ligand was synthesized and the previously reported syntheses of mono- and divalent thiol ligands were improved. Owing to the pristine character of the Au nanoparticles no ligand exchange was required, and the colloidal and chemical stability of the mono- and multivalent functionalized particles purely depended on the ligating ability of the thiolated groups. In situ-functionalized Au nanoparticles showed a strikingly (2 orders of magnitude higher) improved stability against small nucleophiles such as sodium cyanide compared to gold nanoparticles coated with citrate ligands and functionalized via a ligand-exchange reaction. The monovalent thiol PEG ligand produced most stable colloids against cyanide, which is explained by a strongly increased numerical ligand-density on the surface. Gold colloids stabilized by di- and trivalent ligands exhibited high stability in aqueous solutions with high NaCl concentrations (2 M) in contrast to those functionalized with the monovalent PEG ligand, which were only temporally stable in dilute NaCl solutions. The beneficial effect of the multivalence of the ligands was further demonstrated by the incorporation of an additional chelating ligand (dithiothreitol) to the colloidal dispersions.
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Affiliation(s)
- David Zopes
- Department für Chemie, Lehrstuhl für Anorganische und Materialchemie, Universität zu Köln , Greinstraße 6, D-50939 Köln, Germany
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Lee HJ, Jamison AC, Yuan Y, Li CH, Rittikulsittichai S, Rusakova I, Lee TR. Robust carboxylic acid-terminated organic thin films and nanoparticle protectants generated from bidentate alkanethiols. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:10432-10439. [PMID: 23855957 DOI: 10.1021/la4017118] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A new carboxylic acid-terminated alkanethiol having bidentate character, 16-(3,5-bis(mercaptomethyl)phenoxy)hexadecanoic acid (BMPHA), was designed as an absorbate and protectant to form thermally stable carboxylic acid-terminated organic thin films on flat gold and nanoparticles, respectively. The structural features of the organic thin films derived from BMPHA were characterized by ellipsometry, X-ray photoelectron spectroscopy (XPS), and polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), and compared to those derived from mercaptohexadecanoic acid (MHA) and 16-(4-(mercaptomethyl)phenoxy)hexadecanoic acid (MMPHA). This study demonstrates that films derived from BMPHA are less densely packed than films derived from MHA and MMPHA. However, the results of solution-phase thermal desorption tests revealed that the carboxylic acid-terminated films generated from BMPHA exhibit an enhanced thermal stability compared to those generated from MHA and MMPHA. Furthermore, as a nanoparticle protectant, BMPHA can be used to stabilize large gold nanoparticles (~45 nm diameter) in solution, and BMPHA-protected gold nanoparticles exhibited a high thermal stability in solution thermolysis studies.
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Affiliation(s)
- Han Ju Lee
- Department of Chemistry and the Texas Center for Superconductivity, University of Houston, 4800 Calhoun Road, Houston, Texas 77204-5003, USA
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Leifert A, Pan-Bartnek Y, Simon U, Jahnen-Dechent W. Molecularly stabilised ultrasmall gold nanoparticles: synthesis, characterization and bioactivity. NANOSCALE 2013; 5:6224-42. [PMID: 23743952 DOI: 10.1039/c3nr00916e] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Gold nanoparticles (AuNPs) are widely used as contrast agents in electron microscopy as well as for diagnostic tests. Due to their unique optical and electrical properties and their small size, there is also a growing field of potential applications in medical fields of imaging and therapy, for example as drug carriers or as active compounds in thermotherapy. Besides their intrinsic optical properties, facile surface decoration with (bio)functional ligands renders AuNPs ideally suited for many industrial and medical applications. However, novel AuNPs may have toxicological profiles differing from bulk and therefore a thorough analysis of the quantitative structure-activity relationship (QSAR) is required. Several mechanisms are proposed that cause adverse effects of nanoparticles in biological systems. Catalytic generation of reactive species due to the large and chemically active surface area of nanomaterials is well established. Because nanoparticles approach the size of biological molecules and subcellular structures, they may overcome natural barriers by active or passive uptake. Ultrasmall AuNPs with sizes of 2 nm or less may even behave as molecular ligands. These types of potential interactions would imply a size and ligand-dependent behaviour of any nanomaterial towards biological systems. Thus, to fully understand their QSAR, AuNPs bioactivity should be analysed in biological systems of increasing complexity ranging from cell culture to whole animal studies.
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Affiliation(s)
- Annika Leifert
- RWTH Aachen University, Helmholtz Institute for Biomedical Engineering, Biointerface Laboratory, Pauwelsstrasse 30, 52074 Aachen, Germany
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15
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Joshi PP, Yoon SJ, Hardin WG, Emelianov S, Sokolov KV. Conjugation of antibodies to gold nanorods through Fc portion: synthesis and molecular specific imaging. Bioconjug Chem 2013; 24:878-88. [PMID: 23631707 DOI: 10.1021/bc3004815] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Anisotropic gold nanorods provide a convenient combination of properties, such as tunability of plasmon resonances and strong extinction cross sections in the near-infrared to red spectral region. These properties have created significant interest in the development of antibody conjugation methods for synthesis of targeted nanorods for a number of biomedical applications, including molecular specific imaging and therapy. Previously published conjugation approaches have achieved molecular specificity. However, the current conjugation methods have several downsides including low stability and potential cytotoxicity of bioconjugates that are produced by electrostatic interactions, as well as lack of control over antibody orientation during covalent conjugation. Here we addressed these shortcomings by introducing directional antibody conjugation to the gold nanorod surface. The directional conjugation is achieved through the carbohydrate moiety, which is located on one of the heavy chains of the Fc portion of most antibodies. The carbohydrate is oxidized under mild conditions to a hydrazide reactive aldehyde group. Then, a heterofunctional linker with hydrazide and dithiol groups is used to attach antibodies to gold nanorods. The directional conjugation approach was characterized using electron microscopy, zeta potential, and extinction spectra. We also determined spectral changes associated with nanorod aggregation; these spectral changes can be used as a convenient quality control of nanorod bioconjugates. Molecular specificity of the synthesized antibody targeted nanorods was demonstrated using hyperspectral, optical and photoacoustic imaging of cancer cell culture models. Additionally, we observed characteristic changes in optical spectra of molecular specific nanorods after their interactions with cancer cells; the observed spectral signatures can be explored for sensitive cancer detection.
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Affiliation(s)
- Pratixa P Joshi
- Department of Biomedical Engineering and §Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712, United States
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16
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Antonsson E, Bresch H, Lewinski R, Wassermann B, Leisner T, Graf C, Langer B, Rühl E. Free nanoparticles studied by soft X-rays. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2012.11.051] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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17
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Kang JS, Taton TA. Oligothiol graft-copolymer coatings stabilize gold nanoparticles against harsh experimental conditions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:16751-60. [PMID: 22957513 PMCID: PMC3682508 DOI: 10.1021/la301249a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We report that poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) copolymers that bear multiple thiol groups on the polymer backbone are exceptional ligands for gold nanoparticles (AuNPs). In general, these graft copolymer ligands stabilize AuNPs against environments that would ordinarily lead to particle aggregation. To characterize the effect of copolymer structure on AuNP stability, we synthesized thiolated PLL-g-PEGs (PLL-g-[PEG:SH]) with different backbone lengths, PEG grafting densities, and number of thiols per polymer chain. AuNPs were then combined with these polymer ligands, and the stabilities of the resulting AuNP@PLL-g-[PEG:SH] particles against high temperature, oxidants, and competing thiol ligands were characterized using dynamic light scattering, visible absorption spectroscopy, and fluorescence spectrophotometry. Our observations indicate that thiolated PLL-g-PEG ligands combine thermodynamic stabilization via multiple Au-S bonds and steric stabilization by PEG grafts, and the best graft copolymer ligands balance these two effects. We hope that this new ligand system enables AuNPs to be applied to biotechnological applications that require harsh experimental conditions.
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Affiliation(s)
- Jun Sung Kang
- Department of Chemistry, University of Minnesota 207 Pleasant St. SE, Minneapolis, MN 55455
| | - T. Andrew Taton
- Department of Chemistry, University of Minnesota 207 Pleasant St. SE, Minneapolis, MN 55455
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18
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Gadogbe M, Ansar SM, He G, Collier WE, Rodriguez J, Liu D, Chu IW, Zhang D. Determination of colloidal gold nanoparticle surface areas, concentrations, and sizes through quantitative ligand adsorption. Anal Bioanal Chem 2012; 405:413-22. [PMID: 23092965 DOI: 10.1007/s00216-012-6489-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 10/01/2012] [Accepted: 10/08/2012] [Indexed: 01/19/2023]
Abstract
Determination of the true surface areas, concentrations, and particle sizes of gold nanoparticles (AuNPs) is a challenging issue due to the nanoparticle morphological irregularity, surface roughness, and size distributions. A ligand adsorption-based technique for determining AuNP surface areas in solution is reported. Using a water-soluble, stable, and highly UV-vis active organothiol, 2-mercaptobenzimidazole (MBI), as the probe ligand, we demonstrated that the amount of ligand adsorbed is proportional to the AuNP surface area. The equivalent spherical AuNP sizes and concentrations were determined by combining the MBI adsorption measurement with Au(3+) quantification of aqua regia-digested AuNPs. The experimental results from the MBI adsorption method for a series of commercial colloidal AuNPs with nominal diameters of 10, 30, 50, and 90 nm were compared with those determined using dynamic light scattering, transmission electron microscopy, and localized surface plasmonic resonance methods. The ligand adsorption-based technique is highly reproducible and simple to implement. It only requires a UV-vis spectrophotometer for characterization of in-house-prepared AuNPs.
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Affiliation(s)
- Manuel Gadogbe
- Department of Chemistry, Mississippi State University, Mississippi State, Starkville, MS 39762, USA
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Weber M, Bujotzek A, Haag R. Quantifying the rebinding effect in multivalent chemical ligand-receptor systems. J Chem Phys 2012; 137:054111. [DOI: 10.1063/1.4739501] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Huber A, Behnke T, Würth C, Jaeger C, Resch-Genger U. Spectroscopic Characterization of Coumarin-Stained Beads: Quantification of the Number of Fluorophores Per Particle with Solid-State 19F-NMR and Measurement of Absolute Fluorescence Quantum Yields. Anal Chem 2012; 84:3654-61. [DOI: 10.1021/ac3000682] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Alexandra Huber
- Structural
Analysis Division and ‡Biophotonics Division, BAM Federal Institute for Materials Research and Testing, Department 1, Richard
Willstaetter Strasse 11, D-12489 Berlin, Germany
| | - Thomas Behnke
- Structural
Analysis Division and ‡Biophotonics Division, BAM Federal Institute for Materials Research and Testing, Department 1, Richard
Willstaetter Strasse 11, D-12489 Berlin, Germany
| | - Christian Würth
- Structural
Analysis Division and ‡Biophotonics Division, BAM Federal Institute for Materials Research and Testing, Department 1, Richard
Willstaetter Strasse 11, D-12489 Berlin, Germany
| | - Christian Jaeger
- Structural
Analysis Division and ‡Biophotonics Division, BAM Federal Institute for Materials Research and Testing, Department 1, Richard
Willstaetter Strasse 11, D-12489 Berlin, Germany
| | - Ute Resch-Genger
- Structural
Analysis Division and ‡Biophotonics Division, BAM Federal Institute for Materials Research and Testing, Department 1, Richard
Willstaetter Strasse 11, D-12489 Berlin, Germany
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Nanocarriers as Nanomedicines. NANOBIOTECHNOLOGY - INORGANIC NANOPARTICLES VS ORGANIC NANOPARTICLES 2012. [DOI: 10.1016/b978-0-12-415769-9.00014-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Hofmann A, Schmiel P, Stein B, Graf C. Controlled formation of gold nanoparticle dimers using multivalent thiol ligands. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:15165-15175. [PMID: 22029627 DOI: 10.1021/la2028498] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Approaches for the controlled formation of gold nanoparticle dimers are investigated. These are based on a locally confined surface modification of gold nanoparticles followed by bridging two particles with an organic linker. A key factor in these approaches is the use of multivalent ligands. Citrate-stabilized gold nanoparticles are immobilized on a glass surface and mono- and multivalent thiol ligands are investigated regarding their ability to inactivate the nanoparticles sites facing away from the glass. A successful locally confined functionalization is only possible if multivalent ligands are used in this step. The application of monovalent ligands results in less stable particles without a permanent regioselective functionalization. This result can be explained by the dynamic equilibrium between bound and free ligands. Subsequently, the sites of the nanoparticles previously bound to the glass surface are functionalized with thiol ligands additionally bearing a reactive group. Approaches using dithiol linkers, diamine linkers, and coupling complementary functionalized particles are investigated. The highest yield of stable dimers is obtained from conditions where nanoparticles which are regioselectively functionalized with an N-hydroxysuccinimide ester are reacted with complementary amino-functionalized particles. The application of nanoparticles with activated carboxyl groups is essential since standard carboxyl activation agents induce an aggregation of the nanoparticles due to a reaction with remaining citrate molecules on the nanoparticle surface which reduces significantly electrostatic stabilization. This versatile approach using complementary regioselective with multivalent ligands functionalized nanoparticles may be also used for the coupling of particles with different size, shape, or composition, as well as a control of the interparticle distance.
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Affiliation(s)
- Andreas Hofmann
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
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