Immobilization on waveguide surface, analysis of adsorption and dissociation kinetics.
Wide variety of different sensing applications from small drug molecules to large proteins. Ligand/receptor binding study is fundamental for understanding molecular recognition in biology. The whole immune system is based upon that, as well as the blood coagulation cascade, signalling transduction between and within cells.
The OWLS grating coupler sensors can yield the number, size and shape of living cells growing on its surface. The OWLS system allows to quantify the surface area of focal adhesion of living cells, at the surface. The measurement takes place in real time and is noninvasive. Applications include toxicology, stem cell and cancer research. With the addition of electrical field stimulation in EC-OWLS systems, living cell behaviour under electrical field can be studied.
Protein adsorption and desorption applications can be divided into two categories: those in which it is desired to minimize adsorption, and those in which it is desired to maximize it. The grating coupler sensor, by virtue of the unprecedented precision and time resolution with which it is possible to measure adsorption and desorption kinetics, has become an indispensable tool for studies aimed at elucidating the fundamental mechanisms underlying these processes at the molecular level.
In biology, the bilayer lipid membrane (BLM) is probably the most important surface with which proteins interact. The ease with which a BLM can be deposited onto a grating coupler sensor is a major advantage of using the OWLS technology.
Since the grating coupler sensor can be easily coated with very long DNA molecules, it is ideally suited to investigate both hybridization and protein binding.
The very first applications of the OWLS system were in the field of investigating the properties of bilayer lipid membrane and other thin films. The grating coupler sensor has enabled studies of this type to be undertaken much more conveniently than heretofore. Accessible properties include the thickness, density and anisotropy of thin films, and their changes following a perturbation can be followed in real time.
The main application of the grating coupler sensor in this field is drug determination. The waveguide-supported lipid bilayer is closer to the real cell membrane than other model systems. It can be used for rapid, accurate drug screening, as well as for more fundamental studies of the blood-brain barrier.
Although the vast bulk of reported work involves biological molecules, the use of the OWLS grating coupler sensor is by no means confined to them. Due to the high precision with which an assembly process can be followed, the OWLS grating coupler sensor became an essential tool for investigating the fundamentals of self-assembly.