Functional Biosensing Platform for Urea Detection: Copolymer of Fc-Substituted 2,5-di(thienyl)pyrrole and 3,4-ethylenedioxythiophene

Abstract

Biosensing devices for urea detection have become extensively researched as the analysis of urea levels is imperative in biological fluids indicating disorders of renal, hepatic, nervous and blood circulatory systems. The current work describes the development of two biosensing platforms for urea based on electrochemical deposition of ferrocene-substituted 2,5-di(thienyl)pyrrole (SNS-Fc) and copolymerization with 3,4-ethylenedioxythiophene (EDOT) (SNS-Fc-co-EDOT) followed by coupling with multi-wall carbon nanotubes (MWCNTs) and immobilization of Urease (Urs) through cross-linking. Optimum operational parameters (pH, applied potential) and design parameters (enzyme units, cross-linker concentration) were thoroughly investigated. The analytical comparison between P(SNS-Fc)/CNT/Urease and P(SNS-Fc-co-EDOT)/CNT/Urease showed a linear range between 0.01-0.20 and 0.01-0.15 mM, respectively with superior sensitivity (13.49 mAM(-2) cm(-2)) and LOD (1.9 mu M) for the latter. Little to no interference was observed leading to accurate urea detection in real samples.