Nanocauliflowers: A Nanostructured Polyaniline‐Modified Screen‐Printed Electrode with a Self‐Assembled Polystyrene Template and Its Application in an Amperometric Enzyme Biosensor

Abstract

AbstractA simple method for the nanostructuring of polyaniline (PANI)‐modified screen‐printed electrodes (SPE) was developed. Polystyrene (PS) nanoparticles were self‐assembled onto a PANI‐modified SPE with the help of the negatively charged polyelectrolyte poly(sodium 4‐styrenesulfonate) (PSS) and positively charged poly(diallyldimethylammonium chloride) (PDDA). The self‐assembled PS nanoparticles could then act as a template for the electropolymerization of an additional layer of PANI. It was found that the additional layer of PANI preferred to grow around the PS nanoparticles, and a highly nodular, ‘cauliflower–like’ nanostructure of PANI was thus formed on the electrode surface, which was characterized by scanning electron microscopy. The SPE modified with the nanostructured PANI (nano‐PANI) was further used for the immobilization of horseradish peroxidase (HRP) and developed into a biosensor for hydrogen peroxide. Under optimized conditions, the proposed biosensor exhibited a fast response time of about 5 s, a linear range from 2.5×10−6 to 1.9×10−4 μM with a detection limit of 0.36 μM, and a high sensitivity of 41.0 μA mM−1 due to the benefits of the nanostructured PANI.