DEVELOPMENT OF AN ELECTRICALLY WIRED AMPEROMETRIC IMMUNOSENSOR FOR THE DETERMINATION OF BIOTIN BASED ON A NON-DIFFUSIONAL REDOX OSMIUM POLYMER FILM CONTAINING AN ANTIBODY TO THE ENZYME LABEL HORSERADISH-PEROXIDASE
B. Lu et al., DEVELOPMENT OF AN ELECTRICALLY WIRED AMPEROMETRIC IMMUNOSENSOR FOR THE DETERMINATION OF BIOTIN BASED ON A NON-DIFFUSIONAL REDOX OSMIUM POLYMER FILM CONTAINING AN ANTIBODY TO THE ENZYME LABEL HORSERADISH-PEROXIDASE, Analytica chimica acta, 345(1-3), 1997, pp. 59-66
An amperometric immunosensor was developed based on a non-diffusional
redox polymer used for transferring electrons between the electrode su
rface and the antigen (horseradish peroxidase; HRP) bound to the anti-
HRP antibody on the sensing surface. The redox polymer [Os(bpy)(2)(PVP
)(10)Cl]Cl (bpy=bipyridyl, PVP=poly-4-vinylpyridine) was co-immobilise
d with the antibody on the electrode surface by crosslinking the antib
ody with glutaraldehyde to form a combined sensing and electron transf
er system. The resulting sensing film exhibits the classical features
of a kinetically fast redox couple strongly bound to an electrode surf
ace. The properties of the sensor depend on the content of osmium poly
mer, the extent of crosslinking and the loading of the antibody in the
film. The detection limit for HRP of the sensor was found to be 0.01
mu g ml(-1), which is one order of magnitude lower than that for a tra
ditional ELISA experiment. By employing an antibiotin antibody with an
immune-competitive approach, the sensor exhibited excellent performan
ce for the detection of the hapten biotin.