| abstract |
Optical biosensor based on fluorescence energy transfer comprises (1) a solid carrier; (2) a Langmuir-Blodgett (LB) film, having one or more layers, deposited on the carrier (3) at least one fluorescent dye (F1) in at least one of the upper 4 layers of the LB film; (4) a biologically interactive molecule (receptor; R1) bound to, or disposed in, the uppermost layer of the film; and (5) a mobile fluorescent dye (F2), the excitation band of which overlaps sufficiently with the emission band of F1 for energy transfer to occur. F2 is covalently bonded to a ligand (L) which can bind to R1, or is bonded to another receptor (R2) which can bind to the R1-L complex. L, or L+R2, are initially not bonded to the LB film. The carrier is pref. of glass, quartz glass, porcelain, silicon or an opt. metallised plastic and the matrix of the LB film is a polymer to which F1 is covalently bonded. USE/ADVANTAGE - The method is used to detect molecules labelled with fluorescent dye, e.g. in analysis of dissolved antigens, antibodies, etc.. It is simple, provides highly sensitive detection; is widely applicable and the LB films can be prepd. reproducibly. F1 can be chosen for optimal energy transfer and need not be specific for a particular functional molecule. |