Development of transducer matrices based upon nanostructured conducting polymer for application in biosensors

The nanostructured polyaniline (NSPANI) and its gold nano composite (GNP) with controlled size distribution were developed using structure directing agents (SDA). The nano structure of polyaniline were investigated by UV-Visible spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), fourrier transform spectroscopy (FTIR), X-ray crystallography and scanning electron microscopy(SEM) etc. These characterization techniques reveal the spherical shape of polyaniline nanoparticles and size in the range of 7-50 nm depending on the type of dopant and nature of SDA. In general, these NSCP colloidal solutions are highly stable. UV-Visible spectra show mainly two peaks at 360-430 nm and at 780-870 nm. The bathochromic shift of the UV-Visible bands as compared to bulk polyaniline, reflect high DC conductivity. TEM and DLS results demonstrate the formation of nanostructure with narrow size distribution. Due to remarkable properties of, it is used as an efficient transduction matrice for the development of highly sensitive, reproducible, stable optical cholesterol and H202 biosensors having wide range of linearity and low Km values.