Doppler Electrophoretic Light Scattering Analyzer

The Coulter Delsa 440 measures distribution of electrophoretic mobility and zeta potentials of particles and colloids (0.02 - 30 mm diameter) in liquid suspension using laser Doppler velocimetry. The system comprises an optical bench with a helium-neon laser, a sample chamber, a frequency shifter, a 24fold magnification microscope and four photodiode detectors. The beam is spilt into main beam and four reference beams that detect scattered light at four angles. The main beam's frequency is changed by a controlled amount in a frequency shifter, allowing for detection of particle mobility and (surface) properties. This set-up can be used for analysis of nano-particles carrying (multiple) biological surface layers, such as receptors or DNA, which may allow usage of these particles for detection or diagnostics. See below a picture of the setup:



Contact Person at LCVU: Dirk Bald, email: dirk.bald@falw.vu.nl