Effect of pH on stability and plasmonic properties of cysteine-functionalized silver nanoparticle dispersion

Csapó, Edit; Patakfalvi, Rita; Hornok, Viktória; Tóth, L.; Sipos, Áron; Szalai, Anikó; Csete, Mária; Dékány, Imre

doi:10.1016/j.colsurfb.2012.03.036

Cited by 89 publications

(65 citation statements)

References 41 publications

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“…The pI value of Cys-Au obtained is comparable with that in the literature 20 but significantly higher than the reported value of 4.1 for Cys on silver nanoparticles. 21 At low pH, both carboxyl and amine groups are protonated leading to the net positive charge at surfaces, whereas deprotonation at high pH rendered the surfaces negatively charged. It should be noted that the pI values observed for adsorbed Cys and GSH are lower than those in liquid phase (pI ¼ 6.25 and 5.93 for Cys and GSH, respectively), suggesting the effect of substrates on the surface net charge.…”

Section: A Formation and Characterization Of Samsmentioning

confidence: 99%

“…Among these compounds, Cys is the most popular surface ligand for the preparation of biofunctional surfaces, as a model system for the investigation of organic-inorganic interfaces. [15][16][17][18][19][20][21][22][23][24] A variety of techniques, including x-ray photon electron spectroscopy (XPS), ion mass spectroscopy, scanning tunneling microscopy, surfaceenhanced Raman scattering, and surface-enhanced second harmonic generation, have been applied to scrutinize Cys on metals at a molecular level. [15][16][17][22][23][24] The ability of Cysmodified surfaces to repel protein adsorption was also well documented.…”

Section: Introductionmentioning

confidence: 99%

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Natural zwitterionic organosulfurs as surface ligands for antifouling and responsive properties

et al. 2014

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Natural sulfur-containing zwitterionic compounds, l-cysteine (Cys), l-methionine, and glutathionine (GSH), have been employed as surface ligands to prevent protein nonspecific adsorption on planar substrates. These organosulfur compounds form self-assembled monolayers (SAMs) on gold substrates by gold–sulfur interaction. The chemical elements of SAMs were confirmed using x-ray photoelectron spectroscopy. The surface wetting tests for SAMs show that films prepared from Cys and GSH exhibited super-hydrophilicity (contact angles of θ = ∼5°) due to their high coverage and strong hydration via ionic solvation and formation of hydrogen bonding. Quartz crystal microbalance with dissipation sensor was used to quantitatively and qualitatively monitor the adsorption of bovine serum albumin (BSA) from buffer onto these SAMs. It was found that the GSH film enables the resistance of BSA adsorption to the best extent at a physiological pH. Moreover, the surface charges of modified substrates were modulated by varying the pH value to control BSA adsorption. The effect of electrostatic repulsion on the antifouling behavior becomes prominent at a pH where the protein and the surface carry same charges. Consolidating the BSA adsorption measurements at different pH values, the antifouling properties of GSH-modified Au should be attributed to prevention of entropy gain and enthalpy loss, making BSA adsorption energetically unfavorable. It is believed that the surface modification with natural organosulfur ligands holds great potential in improving the biocompatibility of medical devices and in offering intelligent biointerfaces in response to environmental stimuli.

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Section: A Formation and Characterization Of Samsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Natural zwitterionic organosulfurs as surface ligands for antifouling and responsive properties

et al. 2014

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“…The zeta potential of the citrate-reduced Au nanoparticles at pH 7 is −53 mV, 8 which differs from that of the borohydridereduced Au nanoparticles (−36 mV), 19 citrate-reduced Ag nanoparticles (−43 mV), 20 and borohydride-reduced Ag nanoparticles (−46 mV) 17 . The pH of the colloidal solution is also an important parameter determining the surface potentials of nanoparticles.…”

mentioning

confidence: 98%

Investigation of Gold and Silver Nanoparticles as Acid-base pH Indicators and Their Transition pH Ranges

Jung¹,

Jo²,

Yu³

et al. 2014

Bulletin of the Korean Chemical Society

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Monitoring of pH, especially under highly alkaline conditions, is necessary in various processes in the industrial, biotechnological, agricultural, and environmental fields. However, few pH indicators that can function at highly alkaline levels are available, and most of which are organic-based pH indicators. Several years ago, it was reported that gold nanoparticles prepared using trisodium citrate dihydrate were rapidly aggregated at pH values higher than ~12.7. A shift of surface plasmon resonance for such aggregated gold nanoparticles can be applied to pH indicators, allowing for the substitution of traditional organic-based pH indicators. The most important characteristic of pH indicators is the transition pH range. Herein, gold and silver nanoparticles are prepared using different reducing agents, and their transition pH ranges are examined. The results showed that all nanoparticles prepared in this study exhibit similar transition pH ranges spanning 11.9-13.0, regardless of the nanoparticle material, reducing agents, and concentration.

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“…Nowadays the importance of gold nanoparticles (AuNPs) is increasing in several biological and medical applications, because they have a neutral physiological effect, and their expediency in many types of applications such as CT and X-ray contrast materials, 19,20 photothermal therapy, 21,22 drug delivery 23,24 and plasmonic properties 25,26 has been proven. Most of the applications require surface functionalization, either in order to bind proteins, drugs (that do not contain thiol groups) onto the surface of AuNPs or to find the target molecule/group in the course of targeted drug or contrast material delivery.…”

Section: Sebők Adsorption Of Ibuprofen and Dopamine On Functionalmentioning

confidence: 99%

“…where dn/dc is the dependency of refractive index on concentration of adsorbent in the solution (typically 25,26 0.…”

Section: Application Of Spr Sensors In Biological Researchmentioning

confidence: 99%

Adsorption of Ibuprofen and Dopamine on Functionalized Gold Using Surface Plasmon Resonance Spectroscopy at Solid-Liquid Interface

Sebők¹,

Csapó²,

Preočanin³

et al. 2013

Croat. Chem. Acta

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Abstract. Ultrathin gold nanofilms (≈ 50 nm) are suitable for detection of adsorbed molecules at solidliquid interface of various sizes due to their surface plasmon resonance (SPR) properties. This SPR technique makes it possible to study the surface adsorption in nanomol range amount on gold surfaces of a maximum of one mm 2 and to determine the adsorbed amount as a function of equilibrium concentration. Adsorption of L-cysteine, L-glutathione, ibuprofen and dopamine on the gold surface was examined. Moreover, the binding capability of ibuprofen and dopamine molecules on the gold surface functionalized by L-cysteine and L-glutathione was studied as well. Adsorption isotherms were recorded using the flow measuring technique, which allows determination of the amount of adsorbed material even in the nmol/cm 2 order of magnitude, the cross sectional areas of adsorbed molecules. The adsorption enthalpies (isosteric heat of adsorption) were determined from adsorption isotherms at different temperatures. The surface orientations of the studied molecules were analyzed by MarvinSketch program. (doi: 10.5562/cca2343)

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Effect of pH on stability and plasmonic properties of cysteine-functionalized silver nanoparticle dispersion

Cited by 89 publications

References 41 publications

Natural zwitterionic organosulfurs as surface ligands for antifouling and responsive properties

Natural zwitterionic organosulfurs as surface ligands for antifouling and responsive properties

Investigation of Gold and Silver Nanoparticles as Acid-base pH Indicators and Their Transition pH Ranges

Adsorption of Ibuprofen and Dopamine on Functionalized Gold Using Surface Plasmon Resonance Spectroscopy at Solid-Liquid Interface

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