Application of surface acoustic waves for optimisation of biocompatibility of carboxymethylated dextran surfaces

The non-specific binding of a protein to carboxymethylated-dextran (CMD) surfaces was investigated using Reflectometric Interference Spectroscopy (RIfS). Subsequently, these surfaces were optimised for use and optical biosensors regarding biocompatibility. The influence of immobilisation time, concentration of the polymer solution, the amount of carboxylic groups and mixing the solution while preparation of the surfaces were examined. Three different concentrations of the polymer solution were compared using two different immobilisation times for two CMD polymers. For the first time, surface acoustic waves (SAW) were applied for the preparation of CMD surfaces to accelerate immobilisation of the polymer without loss of quality. With mixing the solution while silanisation and immobilisation of the polymer respectively the time for preparation of the sensors could be successfully reduced without increase in non-specific adsorption. The relative amount of reactive binding sites was examined via RIfS using the system Biotin/Streptavidin.