Tuesday, January 24, 2017
Wednesday, November 23, 2016
Wednesday, November 16, 2016
This theory note explains how the surface roughness influences on the contact angle and wettability of the substrate
Both chemical and topographical properties of the surface are important parameters in many different applications and processes, where wetting and adhesion behavior needs to be optimized. Wettability can be studied by measuring the contact angle of the substrate with the given liquid. The well-known Young equation describes the balance at the three-phase contact of solid, liquid and vapor
Monday, June 20, 2016
From tradition SPR to MP-SPR:
From measurements to understanding
Surface Plasmon Resonance (SPR) is an established method for
biomolecular interaction analysis. It is popular due to its sensitivity
as well as its capability to measure label-free and in real-time.
Multi-Parametric Surface Plasmon Resonance (MP-SPR) is based on
SPR principle, however its advantageous optical setup measures
a full SPR curve which enables new insight into interactions.
For instance, PureKinetics™ feature provides measurements of
small molecules, lipids and biomaterials without bulk effect.
MP-SPR widens the application range of traditional SPR from small
molecules up to nanoparticles and even living cells. Measurements
can be performed also in complex media such as serum.
Additionaly, MP-SPR provides information about layer properties.
Thickness and refractive index (RI) data can be utilized in material
characterization from Ångström thick layers up to micrometers
or to ensure conformation of the molecules on the surface.
Premium quality kinetic data with
Bulk effect (sometimes called DMSO effect, salt or solvent artifact) is
the difference in liquid composition between samples and running
buffer. The composition difference is seen as a change in refractive
index, which in turn appears as a shift in measured SPR curve.
In traditional SPR, imaging SPR or localized SPR, only part of the SPR
curve can be seen and therefore, several steps have to be taken in
order to separate true molecular binding from the undesired bulk
The unique optical setup of MP-SPR instruments enables
cross-correlation of parameters provided by the MP-SPR method
and allows simple in-line elimination of interfering bulk signal
using PureKinetics™ feature. This feature is available in all
MP-SPR Navi™ instruments.