Dry-Wet Mass

In situ viscoelastic properties and chain conformations of heavily hydrated carboxymethyl dextran layers

A comparative study using OWLS and QCM-I chips coated with waveguide material

We are very proud that both of our OWLS and QCM-I biosensor systems were used in the recent comparative study published on Nature.com See the abstract below and visit Nature.com to read the full publication. In situ viscoelastic properties and chain conformations of heavily hydrated carboxymethyl dextran layers: a comparative study using OWLS and QCM-I […]

Variations in Coupled Water, Viscoelastic Properties, and Film Thickness of a Mefp-1 Protein Film during Adsorption and Cross-Linking:  A Quartz Crystal Microbalance with Dissipation Monitoring, Ellipsometry, and Surface Plasmon Resonance Study

Abstract We have measured the time-resolved adsorption kinetics of the mussel adhesive protein (Mefp-1) on a nonpolar, methyl-terminated (thiolated) gold surface, using three independent techniques:  quartz crystal microbalance with dissipation monitoring (QCM-D), surface plasmon resonance, and ellipsometry. The QCM-D and ellipsometry data shows that, after adsorption to saturation of Mefp-1, cross-linking of the protein layer […]

Simultaneous determination of optical and acoustic thicknesses of protein layers using surface plasmon resonance spectroscopy and quartz crystal microweighing

Abstract The optical and the acoustic thicknesses of protein layers during adsorption were simultaneously determined by a combination of surface plasmon resonance spectroscopy and quartz crystal microweighing. Coupling of the surface plasmon was achieved by etching a diffraction grating into the quartz surface prior to the deposition of the metal electrode. The evolution of the […]

Fibronectin terminated multilayer films: protein adsorption and cell attachment studies

Abstract Electrostatically driven layer-by-layer (LbL) assembly is a simple and robust method for producing structurally tailored thin film biomaterials, of thickness ca. 10nm, containing biofunctional ligands. We investigate the LbL formation of multilayer films composed of polymers of biological origin (poly(L-lysine) (PLL) and dextran sulfate (DS)), the adsorption of fibronectin (Fn)–a matrix protein known to […]

Using Complementary Acoustic and Optical Techniques for Quantitative Monitoring of Biomolecular Adsorption at Interfaces

Abstract The great wealth of different surface sensitive techniques used in biosensing, most of which claim to measure adsorbed mass, can at first glance look unnecessary. However, with each technique relying on a different transducer principle there is something to be gained from a comparison. In this tutorial review, different optical and acoustic evanescent techniques […]

A comparative study of protein adsorption on titanium oxide surfaces using in situ ellipsometry, optical waveguide lightmode spectroscopy, and quartz crystal microbalance / dissipation

Abstract The adsorption kinetics of three model proteins—human serum albumin, fibrinogen and hemoglobin—has been measured and compared using three different experimental techniques: optical waveguide lightmode spectroscopy (OWLS), ellipsometry (ELM) and quartz crystal microbalance (QCM-D). The studies were complemented by also monitoring the corresponding antibody interactions with the pre-adsorbed protein layer. All measurements were performed with […]