Surface Modification Chemistry Based on the Electrostatic Adsorption of Poly-l-arginine onto Alkanethiol Modified Gold Surfaces

Abstract

The reaction between the arginine's guanidino group and α-dicarbonyl functionalities was used to develop a novel surface modification chemistry. The first modification step consists of the electrostatic adsorption of a poly-l-arginine layer onto ionizable alkanethiol modified gold surfaces. The strongly basic character of the guanidino group of the arginine residues (pK a > 12) guarantees the robust attachment of the polypeptide to negatively charged gold surfaces until very high pH. By varying the pH of the solution from which poly-l-arginine is electrostatically adsorbed, it is possible to control the amount deposited. The availability of the surface guanidino groups of the poly-l-arginine layer for further derivatization with α-dicarbonyl reaction probes, yielding stable heterocyclic condensation adducts, is demonstrated. In addition, the reaction with the heterobifunctional reagent p-azidophenyl glyoxal (APG) provides a surface terminated with a photosensitive aryl azide group which was employed for the photochemical immobilization of proteins to the surface. The application of this surface modification chemistry to immobilize antibodies is demonstrated.

Novel Long-Acting Crystal Formulation of Human Growth Hormone

“…The shape of this adsorption isotherm is consistent with strong adsorption of the poly(arginine) onto the rhGH crystal surface. Electrostatically driven adsorption of the cationic polyelectrolyte onto the negative rhGH crystal surface is fast (completion in less than 10 min), which is consistent with the literature (20), and results in surface charge reversal as shown by electrophoretic mobility (m E ) or zeta potential (z) measurements (Fig. 5b).…”

Highly sensitive and simultaneous electrochemical determination of 2-aminophenol and 4-aminophenol based on poly( l -arginine)-β-cyclodextrin/carbon nanotubes@graphene nanoribbons modified electrode

“…(Shinde et al, 2011;Yang et al, 2013). (Barreira and Silva, 2003;Zhang et al, 2012;Zhu et al, 2015).…”

Superhydrophobic flow channel surface and its impact on PEM fuel cell performance

“…For each kind of samples, 3 parallel samples were prepared, 10 different locations were tested on each of them and standard deviation was calculated. During the tests, 10 ml of Milli-Q water droplets were used for CA and SA; all of the CAs were measured by the ellipse fitting method [55][56][57]. Figure 1 illustrates the experimental setup used for measuring the pressure drop through the graphite channel and visualizing the air/water two-phase flow inside the graphite channel.…”