Coating of polystyrene thin film on glass for protein immobilization in optical biosensor applications

摘要

Immobilizing protein on glass surfaces is typically more difficult and less efficient than on plastic surfaces. Proteins are readily adsorbed on plastic surfaces in a single step. To simplify protein immobilization efficiency on glass surfaces and enhance its efficiency, styrylsilane and polystyrene were coated on glass to serve as protein binding substrates. The efficiency of protein immobilization on plain glass, styrylsilane coated glass, polystyrene thin film coated glass and polystyrene microtiter well were compared. It was found that styrylsilane and polystyrene thin film coated glasses have similar protein immobilization efficiency and kinetics as polystyrene microtiter wells commonly used in immunoassays. Both types of coated glass have a protein binding capacity of approximately 244 picograms/cm~2, polystyrene wells at about 222 picograms/cm~2 and plain glass, 89 picograms/cm~2. Protein immobilization on glass was improved by coating the glass with styrylsilane or polystyrene thin films. This can be done easily and at low cost when compared to traditional methods, making this method very suitable for producing disposable optical fiber and waveguide biosensors. A model biosensor system utilizing recombinant Epstein-Barr viral proteins as antigen targets immobilized on a buried waveguide in the detection of nose and throat cancer is discussed.