Physical Properties of Water Near a Gold Surface: A Nanorheological Analysis

Soares, David Mendez; Tenan, M. A.; Gomide, Andreza Barbosa; Gomes, Wyllerson Evaristo

doi:10.1002/cphc.200900700

Cited by 10 publications

(11 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Gold has previously been shown to be hydrophobic once its cleaned surface is in contact with ambient air or water. , Here, all peptides studied bound to the unmodified gold sensors to varying extent (see Figure a). The U3.5 peptide presented a greater adsorption to bare gold compared to GNNQQNY, NNFGAIL or VQIVYK as it contains the largest amount of hydrophobic (aliphatic and aromatic) residues (see Table ).…”

Section: Resultsmentioning

confidence: 77%

“…Gold has previously been shown to be hydrophobic once its cleaned surface is in contact with ambient air or water. 57,58 Here, all peptides studied bound to the unmodified gold sensors to varying extent (see Figure 3a). The U3.5 peptide presented a greater adsorption to bare gold Following LUB deposition and water (with 1% DMSO) baseline, 100 μM peptide in ultrapure water (with 1% DMSO) was introduced at 50 μL/min for 15 min (iv), followed by an incubation for 45 min (v), and final rinse with ultrapure water (with 1% DMSO) at 200 μL/min (vi).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Adsorption of Amyloidogenic Peptides to Functionalized Surfaces Is Biased by Charge and Hydrophilicity

et al. 2019

View full text Add to dashboard Cite

Surfaces are abundant in living systems, such as in the form of cellular membranes, and govern many biological processes. In this study, the adsorption of the amyloidogenic model peptides GNNQQNY, NNFGAIL, and VQIVYK as well as the amyloid-forming antimicrobial peptide uperin 3.5 (U3.5) were studied at low concentrations (100 μM) to different surfaces. The technique of a quartz crystal microbalance with dissipation monitoring (QCM-D) was applied as it enables the monitoring of mass binding to sensors at nanogram sensitivity. Gold-coated quartz sensors were used as unmodified gold surfaces or functionalized with self-assembled monolayers (SAMs) of alkanethiols (terminated as methyl, amino, carboxyl, and hydroxyl) resulting in different adsorption affinities of the peptides. Our objective was to evaluate the underlying role of the nature and feature of interfaces in biological systems which could concentrate peptides and impact or trigger peptide aggregation processes. In overall, the largely hydrophobic peptides adsorbed with preference to hydrophobic or countercharged surfaces. Further, the glycoprotein lubricin (LUB) was tested as an antiadhesive coating. Despite its hydrophilicity, the adsorption of peptides to LUB coated sensors was similar to the adsorption to unmodified gold surfaces, which indicates that some peptides diffused through the LUB layer to reach the underlying gold sensor surface. The LUB protein-antiadhesive is thus more effective as a biomaterial coating against larger biomolecules than small peptides under the conditions used here. This study provides directions toward a better understanding of amyloid peptide adsorption to biologically relevant interfaces, such as cellular membranes.

show abstract

Section: Resultsmentioning

confidence: 77%

Section: ■ Results and Discussionmentioning

confidence: 99%

Adsorption of Amyloidogenic Peptides to Functionalized Surfaces Is Biased by Charge and Hydrophilicity

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The energy requirement to overcome this hindrance in target strand's exit from the film could play a role in elevation of T m values of the surface-confined duplexes. The other factors that may give rise to the altered "on-surface" T m values could be a different duplex environment at the solid− liquid interface, compared to that in bulk solution, due to different dielectric constant of water near a solid surface 37 and the hydrophilic nature of gold surface. 38,39 For control experiments, the thiolated PNA 3 and DNA 3 sensor strands were immobilized on gold(111) surface keeping the sample preparation condition the same as in the case of immobilization of PNA 1/PNA 2 or DNA 1/DNA 2 oligomers.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…The energy requirement to overcome this hindrance in target strand’s exit from the film could play a role in elevation of T m values of the surface-confined duplexes. The other factors that may give rise to the altered “on-surface” T m values could be a different duplex environment at the solid–liquid interface, compared to that in bulk solution, due to different dielectric constant of water near a solid surface and the hydrophilic nature of gold surface. , …”

Section: Results and Discussionmentioning

confidence: 99%

Facilitating Mismatch Discrimination by Surface-Affixed PNA Probes via Ionic Regulation

2013

View full text Add to dashboard Cite

There has been a search for alternative nucleic acids that can be more effectively used in nucleic acid detection technologies compared to the DNA probes. Peptide nucleic acid (PNA), which contains a non-ionic peptidic backbone, offers such possibilities since it is nuclease-resistant, it binds to DNA with high affinity, and it can be readily self-assembled onto solid substrates, e.g., gold(111), with a molecular backbone orientation away from the substrate. Although application of PNA as a sensor probe has been exemplified, so far there is little or no account of the ionic modulation of single base mismatch discrimination capacity of surface-tethered PNA probes. Herein, we report "on-surface" melting temperatures of PNA-DNA duplexes formed on gold(111) surface, as obtained from fluorescence measurements. We show that surface-tethered PNA forms a stabler duplex than DNA, and is more effective in single base mismatch discrimination than DNA. Importantly, although PNA backbone is non-ionic, variation in the ionic components in hybridization buffer, i.e., varying concentration of monovalent sodium ion, and the nature of anion and the cation, exhibits clear effects on the mismatch discrimination capacity of PNA probes. In general, with decreasing cation concentration, PNA-DNA duplexes are stabilized and mismatch discrimination capacity of the PNA probes is enhanced. The stabilizing/destabilizing effects of anions are found to follow the Hofmeister series, emphasizing the importance of hydrophobic interaction between nucleobases for stability of the PNA-DNA duplexes. Interestingly, the nature of ionic dependence of "on-surface" mismatch detection ability of PNA probes differs significantly from the "solution" behavior of these probes.

show abstract

“…Carbon black particles were removed from polymer substrates using ethanol solutions and an ultrasonic wave and the process was monitored by QCM (Tagawa and Gotoh, ). Quantification of water uptake by organic surfaces with applications in anti‐corrosion films was studied (Rodriguez‐Pardo et al ., ) and the physical characteristics of water close to surfaces were also investigated by QCM (Soares et al ., ). A test for chemical purity base on QCM was developed and tested with a range of compounds and materials and mixes thereof with the results found to correlate well with the more established thermo‐gravimetric analyser approach (Mansfield et al ., ).…”

Section: Small Molecule Interactionsmentioning

confidence: 97%

A Survey of the 2010 Quartz Crystal Microbalance Literature

Speight

Cooper

2012

J of Molecular Recognition

135

View full text Add to dashboard Cite

In 2010 there has again been an increase in the number of papers published involving piezoelectric acoustic sensors, or quartz crystal microbalances (QCM), when compared to the last period reviewed 2006-2009. The average number of QCM publications per annum was 124 in the period 2001-2005, 223 in the period 2006-9, and 273 in 2010. There are trends towards increasing use of QCM in the study of protein adsorption to surfaces (93% increase), homeostasis (67% increase), protein-protein interactions (40% increase), and carbohydrates (43% increase). New commercial systems have been released that are driving the uptake of the technology for characterisation of binding specificities, affinities, kinetics and conformational changes associated with a molecular recognition event. This article highlights theoretical and practical aspects of the principals that underpin acoustic analysis, then reviews exemplary papers in key application areas involving small molecular weight ligands, carbohydrates, proteins, nucleic acids, viruses, bacteria, cells, and membrane interfaces.

show abstract

Physical Properties of Water Near a Gold Surface: A Nanorheological Analysis

Cited by 10 publications

References 26 publications

Adsorption of Amyloidogenic Peptides to Functionalized Surfaces Is Biased by Charge and Hydrophilicity

Adsorption of Amyloidogenic Peptides to Functionalized Surfaces Is Biased by Charge and Hydrophilicity

Facilitating Mismatch Discrimination by Surface-Affixed PNA Probes via Ionic Regulation

A Survey of the 2010 Quartz Crystal Microbalance Literature

Contact Info

Product

Resources

About