Adsorption Behavior and Cross-Linking of EHEC and HM-EHEC at Hydrophilic and Hydrophobic Modified Surfaces Monitored by SPR and QCM-D

Abstract

The adsorption behavior of ethyl(hydroxyethyl) cellulose EHEC and hydrophobically modified EHEC (HM-EHEC) at hydrophilic and hydrophobic surfaces has been studied using surface plasmon resonance (SPR) and quartz crystal microbalance with dissipation monitoring (QCM-D) methods. The adsorbed amounts measured with the different methods were different due to large amounts of water in the films. The slow adsorption process made it reasonable to assume a continuous polymer reconfiguration process at the surface. This was mostly seen for HM-EHEC at the hydrophobic surface, where a more flexible structure was adopted during the adsorption process. A cross-linking agent was seen to truly interpolymer cross-link EHEC at the hydrophilic surface and HM-EHEC at the hydrophobic surface. For EHEC at a hydrophobic surface and for HM-EHEC at a hydrophilic surface, the polymers adsorbed in an individually phase-separated manner, making an interpolymer cross-linking reaction unsuccessful.

Viscoelastic properties of adsorbed and cross-linked polypeptide and protein layers at a solid–liquid interface

“…Varying the density of the adsorbed layer up to 1400 kg/m 3 (density of protein [16]) did not significantly change the mass, shear viscosity or shear modulus of the adsorbed layer and thus did not affect the overall conclusions of this work. This approach has been widely used to analyze QCM-D data as reported for the adsorption of proteins [16], DNA [14,26], and polymers [18,19]. Voigt model were 390-420 and 2510-2580 ng/cm 2 , respectively, as shown in Fig.…”

“…The principles behind this technique have been reported elsewhere [12]. The measurement of changes in frequency and dissipation using QCM-D allows one to estimate the viscoelasticity of the non-elastic adsorbed layer by using Voigt viscoelastic model [13][14][15], which has been used to probe the rheological properties of proteins [16,17] and synthetic polymers [18][19][20] at the solid-liquid interface. Höök et al [16] used this model to study the viscoelasticity of an adsorbed Mytilus edulis foot protein (Mefp-1) film both before and after cross-linking of the adsorbed layer by NaIO 4 .…”

“…Adsorption and viscoelastic properties of type I collagen, in native and heat-denatured forms, on polystyrene was studied by Gurdak et al [17]. Adsorption kinetics and cross-linking of ethyl(hydroxyethyl) cellulose (EHEC) and hydrophobically modified EHEC at hydrophilic and hydrophobic modified surfaces have been investigated in detail by Hedin et al [18].…”

Construction of simultaneous SPR and QCM sensing platform

“…Furthermore, simultaneous sensing systems combining the QCR and surface plasmon resonance (SPR) have recently been explored to improve the sensitivity and reliability of both sensor systems [8][9][10][11][12]. In these applications, two types of response based on the piezoelectricity and surface plasmons are used as the main information.…”

Photo‐immobilization of biological components on gold‐coated chips for measurements using surface plasmon resonance (SPR) and a quartz crystal microbalance (QCM)

“…Of the measurement methods, surface plasmon resonance (SPR) (Baac et al, 2006;Hodin et al, 2007;Jacquemart et al, 2008;Suenaga et al, 2003;Wolf et al, 2005) and quartz crystal microbalance (QCM) (Hodin et al, 2007;Jenkins et al, 2004;Nakano et al, 2007;Rawle et al, 2007;Sota et al, 2002) are very popular. For these measurements, some types of sensor chips are commercially available, although there are in general numerous immobilization methods (Rusmin et al, 2007).…”