In this work, the initial growth process of a polypyrrole/oligonucleotide (PPy/ODN)nanocomposite electrochemically synthesized on an indium tin oxide (ITO)-coated glass surface was investigated by means of chronoamperometric measurements combined with optical microscopy and atomic force microscopy (AFM). It was found that the growth of PPy/ODNonto ITO was a three-stage process including incubation, rapid nucleation and growth, and constant nucleation and growth. The presence of ODN molecules significantly shortened the first stage. Further analysis showed that the nucleation and growth mechanism of PPy/ODN was progressive nucleation and 3D growth, which then changed to instantaneous nucleation and 3D growth before nucleus overlapping. In the third stage, the nucleation and growth
mechanism of PPy/ODN was a combination of progressive nucleation and 3D growth and instantaneous nucleation and 3D growth.