| abstract |
The invention concerns biosensors, the method for obtaining them and their uses in particular for detecting, assaying or locating, in direct immunofluorescence, a ligand such as an antigen or a hapten, in a heterogeneous population. Said biosensors consist of (i) at least a protein-type receptor fragment, capable of binding with a suitable ligand via an active site and in which fragment, at least one of its amino acid residues, located in the proximity of said active site is naturally present in the form of a Cys residue or is substituted in Cys residue, and (ii) a fluorophore coupled with said Cys residue(s). |