Novel eco-friendly water-based conductive ink for the preparation of disposable screen-printed electrodes for sensing and biosensing applications

Abstract

This paper presents a novel water-based conductive ink obtained by proper combination of chitosan (C) biopolymer, graphite (G) powder, and glycerol (G), and its subsequent use in the screen-printing of disposable electrodes on polyethylene terephthalate (PET) plastic obtained from recyclable soda bottles (CGG/PET electrodes). The electrode was used in two directions, as a sensor for the quantification of uric acid and as a biosensor for the enzymatic quantification of catechol. The linear sweep voltammetry-detection of uric acid (UA), showed a linear range between 8.0 and 500 μmol L−1 and a limit of detection (LOD) of 0.36 μmol L−1. Additionally, the performance of the resulting electrodes for biosensing purposes was evaluated through the development of a catechol biosensor by the modification of the GCG/PET surface with the tyrosinase (Tyr) enzyme, multiwalled carbon nanotubes (MWCNTs), and dyhexadecyl phosphate (DHP) (Tyr-MWCNT-CGG/PET). Using the chronoamperometry technique a linear relationship from 0.5 to 50 μmol L−1 and LOD of 0.3 μmol L−1 were achivied for catechol. The proposed electrode has demonstrated outstanding analytical characteristics, proving its potential as a disposable, low-cost, and environmentally friendly platform for electrochemical sensing and biosensing purposes.