Performance enhancement of polypyrrole based nano-biosensors by different enzyme deposition techniques

This chapter presents a comparison of results from a range of experiments carried out to investigate the performance dependency of polypyrrole based nano-biosensors on fabrication and enzyme immobilization techniques. The methods compared are drop casting, co-entrapment, and electrophoretic enzyme deposition techniques. Templated polypyrrole nanotube array sensors provided high sensitivities and quick response times. The size of the template pore diameter plays a vital role in enzyme immobilizing in terms of loading capacity. Application of a polymer cross linking agent provided enhanced sensitivities. However, the response time of the crosslinked sensor was little longer than that of the physical adsorption type enzyme loading. The templated nanostructures have recorded a glucose measurement sensitivity of 62.5 mAM−1 cm−2 with a response time of 6 s. In contrast to the templated method nano-corrugated polypyrrole structures were fabricated on Indium Tin Oxide planar surface using pulse deposition method. The electrochemically developed nano-corrugated polypyrrole sensors with enzyme loaded under high electric field of 1 kV/m have displayed an extremely high sensitivity of 325 mAM−1 cm−2. The study shows the enzyme immobilizing techniques play a great role in the conducting polymer based nano-biosensor performance. © 2019, Springer Nature Switzerland AG.