In the field of biological analysis, the need for multiparametric analysis
has prompted the development of supports bearing a series of biomolecules l
inked to a support in a precise location (addressed). To reach a high infor
mation density, miniaturization of this kind of support has to be carried o
ut. We describe in this paper an approach involving the use of electro-cond
ucting polymers such as polypyrrole. This technology is based on an electro
-directed copolymerization of pyrrole and oligodeoxynucleotides (ODN) linke
d to a pyrrole residue. The process allows the grafting of the selected ODN
at the surface of the successively addressed microelectrodes. In this way,
the syntheses are carried out on 50 mu m electrodes on passive chips or on
active (multiplexed) chips bearing 48 or 128 gold microelectrodes, respect
ively. The detection of biological targets recognized by the biochip is car
ried out by using fluorescent tracers. This technology, involving prepurifi
ed materials precisely addressed, allows better reproducibility of the bioc
hip preparation and, then, an easy interpretation of the fluorescence resul
ts. The versatility of this technology is illustrated by ODN or peptide cop
olymerizations leading to DNA chips or peptide chips, respectively. This wo
uld open the field for other biological interaction studies. (C) 1998 Elsev
ier Science B.V. All rights reserved.