Ellipsometry is analytical technique that measures polarisation of light reflected off a surface. It gains sensitivity by measuring phase shift between components of polarisation rather than intensity. Precision ellipsometry (PREL) contains a polarisation modulator, which makes it even more sensitive down to micro-radians. This translates to sensitivity of 0.01 nm of organic molecules on silicon.
Precision ellipsometry enables quantitative real-time measurement of molecular interactions: such as binding, attachment, and detachment. It is used to measure the kinetics of chemical reactions by fixing one of the reagents on a reflecting surface and supplying the other in a medium: gas or liquid. It is used also as a molecular sensor by fixing the respective receptor on the surface. It can be used in other applications, where molecular sensitivity is required.
Technology Features, Specifications and Advantages
- Polarisation modulator is compact, cheap and consumes low power; thus PREL system is portable and can be powered from a battery.
- PREL has sensitivity at the molecular level and can measure deposition of molecular layers from gas and from the liquid where the substrate is placed in an optical cuvette.
- PREL uses cost-effective silicon substrates, providing low price per test, yet with the same level of sensitivity as the "gold standard" for molecular layers: surface plasmon resonance, which works on expensive gold substrates.
PREL can be applied in (but not limited to):
- Real-time measurement of formation of molecular multi-layers, as it is able to measure sequential molecular binding in one run
- Chemical and pharmaceutical industries, due to its sensitivity, for at-line monitoring of properties of precursors and products
- Portable applications, such as "in the field" for environmental monitoring
- Portable and battery powered
- High sensitivity
- Real-time measurement
- Uses cost-effective substrates