FLUORESCENT AND PHOSPHORESCENT STUDY OF LANGMUIR-BLODGETT ANTIBODY FILMS FOR APPLICATION TO IMMUNOSENSORS

Methods of quartz support surface modification by various silanisation agents in the gas phase for covalent immobilisation of LB antibody films on their surface were studied. Glycidoxypropyltrimethoxysilane quartz surface modification in the gas phase ensures 2 pmol/cm2 density of the immobilised LB film of monoclonal antibodies at the surface pressure of the formed layer equal to 40 mN/m. By using fluorescent europium labelled antibodies for LB film formation, the value of the surface pressure was found that promotes the most densest packing of antibodies at the liquid-gas phase interface. With the help of fluorescent measurement, various methods of transferring IgG LB films onto supports have been evaluated. When IgG films were transferred onto glycidoxypropyltrimethoxysilane-activated quartz surfaces by the horizontal lift method, about 85% of the deposited antibodies were covalently bound to the support. The immunological activity of the LB film of monoclonal antibodies covalently-bound with the support surfaces, determined on the basis of antibody binding to low-molecular phosphorescent antigen, was 46% of the total amount of the antigen binding centres.