Luminescence biosensors

A novel optical biosensor for homogeneous immunoassay has been developed on the basis of the finding that electrochemical luminescence of pyrene-labelled antigen is extremely inhibited by immunochemical complexation. Electrochemical luminescence homogeneous immunoassay for human serum albumin (HSA), as a model analyte, was performed with a platinum plate electrode which was located in the vicinity of an optical fibre tip. HSA was determined in the concentration range of 3-25 X 10(-6) mol/l. To improve electrochemical luminescence measurement an optical fibre electrode has been developed by fabricating a transparent platinum film on the top of an optical fibre. The minimum detectable limit of luminol was 10(-11) mol/l with the optical fibre electrode. Luminol was applied as a label for homogeneous immunoassay.