Model Bacterial Extracellular Polysaccharide Adsorption onto Silica and Alumina:  Quartz Crystal Microbalance with Dissipation Monitoring of Dextran Adsorption

Abstract

Quartz crystal microbalance with dissipation monitoring (QCM-D) was used to investigate dextran adsorption to alumina and silica. Sensitive adsorption measurements combined with determination of nanometer-scale polymer conformations demonstrate the utility of this technique for studying biopolymer adsorption. The adsorbed amounts and polymeric structures of dextran were determined on A12O3 and SiO2 by real-time monitoring of resonance frequency and energy dissipation changes (deltaf and deltaD). After the sample was rinsed, the apparent mass of retained dextran was 83 ng/cm(2) on the alumina surface and 9 ng/cm2 on the silica surface based on the frequency and energy dissipation changes. The deltaD/deltaf ratios were significantly different on the two surfaces, indicating different conformations of the polymers. On alumina, the ratio changed as adsorption proceeded indicating changes of dextran conformation from the initial to latter adsorption steps. On silica, the ratio did not change during the experiments. Therefore, the dissipation and frequency data suggest significantly different mechanisms of dextran adsorption on alumina and silica surfaces. Molecular dynamics simulations of 12 monomeric units of dextran on a silica slab illustrated that H2O molecules lead to loosely bound dextran structure onto the SiO2 surface, consistent with the observed high-energy dissipation in the QCM-D experiments.

Influence of natural organic matter on the deposition kinetics of extracellular polymeric substances (EPS) on silica

“…By employment of attenuated total internal reflection infrared spectroscopy (ATR-FTIR), Omoike et al [21] examined the interaction of EPS with goethite (␣-FeOOH) surface. Kwon et al [22] utilized quartz crystal microbalance with dissipation (QCM-D) to investigate the deposition of dextran (chosen to represent polysaccharides in EPS) on alumina and silica. Subsequently, using atomic force microscopy (AFM), Kwon et al [13] compared the interactions of silica surfaces with three different homopolymers selected to represent different components of EPS.…”

Adhesive Bond Stiffness of Staphylococcus aureus with and without Proteins That Bind to an Adsorbed Fibronectin Film

“…The more common application of QCM is for sensing the adsorption of molecular mass (6,17). In conventional massloading theory, the adsorbed mass is assumed to couple directly to the sensor surface, increasing its effective mass, which reduces its resonance frequency according to Sauerbrey's relation (20).…”

Investigation of the adsorption characteristics of natural organic matter from typical Chinese surface waters onto alumina using quartz crystal microbalance with dissipation

“…QCM-D technology has been previously described [16,17,20,21]. A QCM-D E1 system (Q-Sense AB, Gothenburg, Sweden) was used to examine the adsorption of NOM onto Al 2 O 3 surfaces.…”

“…doi:10.1016/j.jhazmat.2012.02.039 adsorption sites and with many unknown factors regarding natural organic adsorbates, few researchers have attempted to apply surface complexation models to experimental data. Quartz crystal microbalance with dissipation monitoring (QCM-D) is a useful technique for low-affinity cases, as QCM-D can quantify relatively low levels of adsorbed NOM (ng cm −2 ) in real-time monitoring [16]. Recently, the QCM-D technique was used in environmental studies to detect the adsorption of organic compounds such as dispersants [17,18] and bacterial extracellular polysaccharides to SiO 2 surface [16,19] due to the high sensitivity of this technique.…”