Ssens supplies a range of SPR sensors that are based on borosilicate glass with a refractive index of 1.51 and a thickness of 0.3 or 1 mm. We can provide these sensors in various dimensions and they are compatible with common, commercial SPR instruments. The gold evaporation procedure that is applied to manufacture these substrates was optimized with respect to gold layer thickness and crystallinity. For good adherence of the gold to the glass a thin titanium layer is applied.Ssens can provide SPR sensors with any type of chemical functionality. The most common functionalities are carboxylic acid and primary amine groups, COOH and NH2 respectively. These groups can be used in immobilization reactions, for instance by using aqueous carbodiimide chemistry.
The functional surfaces are divided into two categories; on the P-type substrates the functional groups are present in a thin planar surface layer and immobilization only occurs at the surface. On the G-type surface the functional groups are present in a 3 dimensional, gel like layer. Upon immobilization of a ligand to these functional groups, the interaction with these surfaces is not only determined by the nature of the ligand but also by the nature of the background onto which the ligand is immobilized.
Ssens supplies surfaces with different types of background. Upon contact with biological samples (e.g. protein solutions), the surfaces will show no or minimal a-specific interaction. All products are packed under nitrogen.