Ink-jet-printed CuO nanoparticle-enhanced miniaturized paper-based electrochemical platform for hypochlorite sensing.

Herein, a miniaturized, three-electrode paper-based electrochemical sensing platform for selective and sensitive electroanalytical sensing of hypochlorite has been reported. A hybrid method for fabricating the electrochemical device on the paper-based substrate, using ink-jet printing with conductive carbon inks as counter and reference electrode, has been demonstrated. Further, a CuO@Graphite sheet was incorporated separately using adhesive double-sided tape on the paper-based substrate, which served as the working electrode. The prepared device was subjected to hypochlorite solution of 1 mM to explore the electrochemical behavior of chlorine. Cyclic voltammetry (CV) and square-wave voltammetry (SQWV) were leveraged in the potential window of − 0.7 V to 0 V for conducting the experiments, whereby a sharp reduction peak at a peak potential E⁰ = − 0.43 V vs Ag/AgCl was obtained. Further, the consequence of potential scan rate and the effect of concentration and interference from other chemicals were also analyzed. A linear concentration range of 90–10 nM and a detection limit of 13.15 nM (9.78 × 10^–4 ppm) with standard deviation of 1.013 were obtained. The fabricated paper-based electrode system was also tested on real samples such as lake water and tap water and the results are presented. [ABSTRACT FROM AUTHOR]