Effect of pH on surface energy of glass and Teflon and theoretical prediction of Staphylococcus aureus adhesion

Hamadi, Fatima; Latrache, Hassan; Zekraoui, M.; Ellouali, Mostafa; Bengourram, Jamaâ

doi:10.1016/j.msec.2008.10.023

Cited by 54 publications

(21 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…No clear trend is observed in these data. This agrees with previous results for comparable surfaces obtained with the drop method (Welzel et al 2002) but disagreement exists between the drop method and the plate method and probably the preequilibration in the drop approach also plays a role (Hamadi et al 2009). We are confident that the plate method data are reliable, since we have found similar trends with other surfaces.…”

Section: Contact Angles As a Function Of Phsupporting

confidence: 91%

“…For example for Teflon we found that the extremum of the advancing contact angle obtained with the plate method also coincided with the measured isoelectric point (Lützenkirchen et al, in preparation). Data published by Hamadi et al (2009) obtained with the drop method for samples pre-equilibrated with the respective solutions show exactly the same patterns as our plate method data. This makes us confident that the trends are real, but we plan to do more experimental work on the Teflon system to ascertain our data.…”

Section: Contact Angles As a Function Of Phsupporting

confidence: 80%

See 1 more Smart Citation

Some data and simple models for the silanated glass-electrolyte interface

2010

View full text Add to dashboard Cite

The interface between silanated glass and aqueous KCl electrolyte solutions was studied by zeta-potential and contact angle measurements. Variation of the pH in the zeta-potential measurements yielded a sharp isoelectric point (IEP) at about pH 4, which was independent of the KCl concentration. This particular pH corresponds to zero electrokinetic potential for many hydrophobic surfaces encompassing Teflon, polyethylene and others.The results are interpreted in terms of hydroxide adsorption at the silanated glass-aqueous interface. A previously developed model for such inert surface-electrolyte interfaces is applied to the experimental data. The model parameters are within the range of those previously obtained for comparable surfaces.Discrepancies were observed in pH dependent contact angle measurements, which were done using both the plate Dedicated to the memory of Professor Andrzej Waksmundzki on the occasion of the celebration of his 100th birthday.J. Lützenkirchen ( ) and the drop method: advancing contact angles were always higher than receding contact angles. Advancing contact angles using the drop method yielded no clear tendency as a function of pH and lower values than those obtained by the plate-method. Overall the contact angle data are presented but deemed difficult to interpret in terms of pH dependence and relation to zeta-potentials. A preliminary description of the contact angle data is attempted via the Lippman-Young equation for the different contact angle data sets based on the model potentials. The model results are discussed.Zeta-potential measurements were also performed as a function of salt content within a narrow pH range. As would be expected the presence of a 2:1 electrolyte (BaCl 2 ) results in lower absolute values when compared to the KCl case.

show abstract

Section: Contact Angles As a Function Of Phsupporting

confidence: 91%

Section: Contact Angles As a Function Of Phsupporting

confidence: 80%

Some data and simple models for the silanated glass-electrolyte interface

2010

View full text Add to dashboard Cite

show abstract

“…Qualitatively, the lipid multilayers are observed to be more stable on a PS surface than on a glass slide—lipid dewetting instabilities can occur within hours on glass with exposure to ambient RH. We attribute this substrate dependence to the different surface energies of PS and glass;28, 29 as PS is more hydrophobic than glass. Other potential limitations that affect the lateral resolution of stamped features is the stamp deformation during stamp removal from the silicon master and during contact with the substrate 30.…”

Section: Resultsmentioning

confidence: 99%

Avidin Decorated Core–Shell Nanoparticles for Biorecognition Studies by Elastic Light Scattering

et al. 2007

View full text Add to dashboard Cite

In this paper, a straightforward method based on elastic light scattering is shown to provide a sensitive and reliable tool for the quantitative determination of protein-ligand interactions that occur at the surface of suitably designed core-shell nanoparticles. The assay makes use of monodisperse nanocolloids that have minimal optical contrast with the aqueous environment. By properly coating the particles with avidin and oligo(ethylene glycol)-based amphiphiles, we developed a hybrid system that combines the availability of standard ligands with the necessary bioinvisibility towards the accidental adsorption of nonspecific macromolecules. This probe was employed to detect interactions between different kinds of biotinylated proteins, and it revealed high specificity and affinities in the low nanomolar range. In particular, we obtained an efficient avidin anchorage of biotinylated protein A on the surface of the nanoparticles, which we exploited as a functional probe for the rapid, quantitative, picomolar detection of human IgG antibodies. Overall, these light-scattering-based nanosensors appear as a simple and highly informative tool for proteomics studies.

show abstract

“…The ionic strength of the medium influences the bacterial adhesion to surfaces by interfering with their mutual electrostatic interactions. A variation in pH may change the ionization state of functional groups (i.e., carboxyl and amino groups) present on the bacteria surface and, consequently, the electrostatic forces between the bacteria and the substrate [79]. The bacteria-surface adhesion has been reported to be the highest at a pH of the medium close to the isoelectric point of the bacteria, that is, at the point of zero charge, due to absence of electrostatic repulsion forces [49,80].…”

Section: Environmental Factorsmentioning

confidence: 99%