Abstract: “In biomedical application, it is essential to perform the detection in human serum in most of cases. However, the main difficulty of using serum is high non-specific binding between the sensor surface and serum proteins. The modifications of sensor surfaces were studied in this work. The self assemble monolayer (SAMs) and hydrophilic polymer dextran were coated on gold substrate with chemisorption method and was tested in the property of a repelling the non-specific binding of human serum by monitoring via Surface Plasmon resonance technique (SPR) gtecnique. SPR is an optical technique, which is highly sensitive on the change of the optical properties of the biomolecules in nanoscale. The results were shown that there was effect of serum dilutions on both of the sensors. It was shown the effect of increasing the human serum concentration on the SPR signal increasing. The efficiency of repelling human serum in both SAMs and dextran was shown different. Dextran gave a lower non-specific”

Keywords: Surface Plasmon resonance, thin film, nonspecific binding