Polyaniline/sulfonated cassava starch: A green biocomposite for sensing of pyridoxine

Abstract

Schematic representation of the electrode modification using PANi-SCS biocomposite • The synthesized PANi/SCS composite by simple chemical method towards selective determination of Pyr was evaluated for the very first time in biosensor field. • The fabricated PANi/SCS green biocomposite showed excellent sensitivity towards the oxidation of Pyr with detection limit of 39 nM. • The real sample analysis demonstrated better sensing results proposing it for food diagnostic applications. Interest in natural polymers has increased because of their unique properties, and these polymers have recently found broad applications. However, further exploration of biosensor applications is necessary. Vitamin deficiencies lead to numerous diseases worldwide; consequently, detection of the vitamin pyridoxine (Pyr) is crucial. To that end, we investigated a polyaniline (PANi)-sulfonated cassava starch (SCS)-based nanocomposite for electrochemical sensing of Pyr. Unlike other metal/metal oxide and polymer based composites, this biopolymer was prepared through a simple green synthesis route. The hydrophilic/hydrophobic ends in SCS provide greater surface area to accommodate PANi for composite formation. In addition, the SO 3 groups replace the primary OH groups through sulfonation, thus increasing binding to the OH groups of Pyr. The enhanced redox behavior of the PANi/SCS nanocomposite enabled selective sensing of Pyr over a broad range of 400 nM to 900 µM, with a low detection limit of 39 nM. Finally, Pyr detection was evaluated on banana extract, thereby demonstrating the practical utility of this method. Thus, our composite is a promising platform for food diagnostic applications.