Limits...
Modification of hydrophilic and hydrophobic surfaces using an ionic-complementary peptide.

Yang H, Fung SY, Pritzker M, Chen P - PLoS ONE (2007)

Bottom Line: In contrast, the water contact angle decreases significantly from 71.2+/-11.1 degrees to 39.4+/-4.3 degrees after the HOPG surface is coated with a 29 microM peptide solution for 2 h.The stability of the EAK16-II nanofibers on both surfaces is further evaluated by immersing the surface into acidic and basic solutions and analyzing the changes in the nanofiber surface coverage.This work demonstrates the possibility of using self-assembling peptides for surface modification applications.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada.

ABSTRACT
Ionic-complementary peptides are novel nano-biomaterials with a variety of biomedical applications including potential biosurface engineering. This study presents evidence that a model ionic-complementary peptide EAK16-II is capable of assembling/coating on hydrophilic mica as well as hydrophobic highly ordered pyrolytic graphite (HOPG) surfaces with different nano-patterns. EAK16-II forms randomly oriented nanofibers or nanofiber networks on mica, while ordered nanofibers parallel or oriented 60 degrees or 120 degrees to each other on HOPG, reflecting the crystallographic symmetry of graphite (0001). The density of coated nanofibers on both surfaces can be controlled by adjusting the peptide concentration and the contact time of the peptide solution with the surface. The coated EAK16-II nanofibers alter the wettability of the two surfaces differently: the water contact angle of bare mica surface is measured to be <10 degrees , while it increases to 20.3+/-2.9 degrees upon 2 h modification of the surface using a 29 microM EAK16-II solution. In contrast, the water contact angle decreases significantly from 71.2+/-11.1 degrees to 39.4+/-4.3 degrees after the HOPG surface is coated with a 29 microM peptide solution for 2 h. The stability of the EAK16-II nanofibers on both surfaces is further evaluated by immersing the surface into acidic and basic solutions and analyzing the changes in the nanofiber surface coverage. The EAK16-II nanofibers on mica remain stable in acidic solution but not in alkaline solution, while they are stable on the HOPG surface regardless of the solution pH. This work demonstrates the possibility of using self-assembling peptides for surface modification applications.

Show MeSH

Related in: MedlinePlus

Schematic diagram of EAK16-II structure.The red portion shows the hydrophilic side of the peptide and the green portion shows the hydrophobic side of the peptide.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2117347&req=5

pone-0001325-g001: Schematic diagram of EAK16-II structure.The red portion shows the hydrophilic side of the peptide and the green portion shows the hydrophobic side of the peptide.

Mentions: In this study, we demonstrate how a model ionic-complementary peptide EAK16-II (Figure 1) assembles on a hydrophilic (mica) and a hydrophobic (HOPG) surface. This peptide has been extensively studied in our group [30]–[32]. We take this research one step further by examining how the assembly of EAK16-II modifies mica and HOPG surfaces. The operation of AFM in liquid is the primary method used to observe the peptide assembly on the model surfaces. The hydrophobicity of the peptide-modified surfaces is characterized by water contact angle measurements. The stability of the modified surfaces in acidic and alkaline solutions is evaluated in terms of the surface coverage changes determined from AFM image analysis. The information obtained in this study is aimed at providing a more complete picture of the peptide assembly on both hydrophilic and hydrophobic surfaces and investigating whether peptides such as EAK16-II can be used to modify electrodes to enhance the biocompatibility of the surface for the immobilization of biomolecules and further use as (bio)molecular sensors.


Modification of hydrophilic and hydrophobic surfaces using an ionic-complementary peptide.

Yang H, Fung SY, Pritzker M, Chen P - PLoS ONE (2007)

Schematic diagram of EAK16-II structure.The red portion shows the hydrophilic side of the peptide and the green portion shows the hydrophobic side of the peptide.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2117347&req=5

pone-0001325-g001: Schematic diagram of EAK16-II structure.The red portion shows the hydrophilic side of the peptide and the green portion shows the hydrophobic side of the peptide.
Mentions: In this study, we demonstrate how a model ionic-complementary peptide EAK16-II (Figure 1) assembles on a hydrophilic (mica) and a hydrophobic (HOPG) surface. This peptide has been extensively studied in our group [30]–[32]. We take this research one step further by examining how the assembly of EAK16-II modifies mica and HOPG surfaces. The operation of AFM in liquid is the primary method used to observe the peptide assembly on the model surfaces. The hydrophobicity of the peptide-modified surfaces is characterized by water contact angle measurements. The stability of the modified surfaces in acidic and alkaline solutions is evaluated in terms of the surface coverage changes determined from AFM image analysis. The information obtained in this study is aimed at providing a more complete picture of the peptide assembly on both hydrophilic and hydrophobic surfaces and investigating whether peptides such as EAK16-II can be used to modify electrodes to enhance the biocompatibility of the surface for the immobilization of biomolecules and further use as (bio)molecular sensors.

Bottom Line: In contrast, the water contact angle decreases significantly from 71.2+/-11.1 degrees to 39.4+/-4.3 degrees after the HOPG surface is coated with a 29 microM peptide solution for 2 h.The stability of the EAK16-II nanofibers on both surfaces is further evaluated by immersing the surface into acidic and basic solutions and analyzing the changes in the nanofiber surface coverage.This work demonstrates the possibility of using self-assembling peptides for surface modification applications.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, Canada.

ABSTRACT
Ionic-complementary peptides are novel nano-biomaterials with a variety of biomedical applications including potential biosurface engineering. This study presents evidence that a model ionic-complementary peptide EAK16-II is capable of assembling/coating on hydrophilic mica as well as hydrophobic highly ordered pyrolytic graphite (HOPG) surfaces with different nano-patterns. EAK16-II forms randomly oriented nanofibers or nanofiber networks on mica, while ordered nanofibers parallel or oriented 60 degrees or 120 degrees to each other on HOPG, reflecting the crystallographic symmetry of graphite (0001). The density of coated nanofibers on both surfaces can be controlled by adjusting the peptide concentration and the contact time of the peptide solution with the surface. The coated EAK16-II nanofibers alter the wettability of the two surfaces differently: the water contact angle of bare mica surface is measured to be <10 degrees , while it increases to 20.3+/-2.9 degrees upon 2 h modification of the surface using a 29 microM EAK16-II solution. In contrast, the water contact angle decreases significantly from 71.2+/-11.1 degrees to 39.4+/-4.3 degrees after the HOPG surface is coated with a 29 microM peptide solution for 2 h. The stability of the EAK16-II nanofibers on both surfaces is further evaluated by immersing the surface into acidic and basic solutions and analyzing the changes in the nanofiber surface coverage. The EAK16-II nanofibers on mica remain stable in acidic solution but not in alkaline solution, while they are stable on the HOPG surface regardless of the solution pH. This work demonstrates the possibility of using self-assembling peptides for surface modification applications.

Show MeSH
Related in: MedlinePlus