| abstract |
Optical biosensor comprises (1) a solid carrier; (2) a Langmuir-Blodgett (LB) film, with one or more layers deposited on the carrier; (3) at least one fluorescent dye (F1) in at least one of the 4 top layers of the LB film; (4) a molecule (receptor; R1) capable of specific interaction bound to, or disposed within, the uppermost layer of the LB film, and (5) a mobile fluorescent dye (F2) the excitation band of which overlaps the emission band of F1 sufficiently for energy transfer to occur. F2 is (a) covalently bonded to a ligand (L) which can bind to R1 or (b) covalently bonded to another receptor (R2) which can bind to a complex of R1 and L; L (or L plus R2) are not initially bound to the LB film. The solid carrier is e.g. of glass; porcelain; semiconductor (e.g. Si or Ge); metal or opt. metallised plastic, and its surface may be modified. The matrix of the LB film is a polymer to which F1 is covalently bonded. |