Highly sensitive and reusable Cu⁺²/polyaniline/reduced graphene oxide nanocomposite ink-based non-enzymatic glucose sensor

Abstract

The present work focuses on the preparation and characterizations of a highly sensitive, reusable, linear, anti-interferent, and low-cost Cu⁺²/polyaniline (PANI)/reduced graphene oxide (rGO) nanocomposite ink-based non-enzymatic glucose (NEG) sensor. The synergistic properties of Cu⁺²/PANI and rGO result in a large number of electrochemically active and stable sites which catalytically favored the glucose oxidation. The crystal structure and morphology of PANI, Cu⁺²/PANI composite, and Cu⁺²/PANI/rGO nanocomposite ink encouraged the usefulness of Cu⁺²/PANI/rGO nanocomposite ink as an electrocatalyst in NEG detection. A NEG sensor was prepared by drop coating Cu⁺²/PANI/rGO nanocomposite ink on a low-cost patterned FR4 electrode. The cyclic voltammetry and chronoamperometry tests were performed to estimate the electrochemical behavior of prepared Cu⁺²/PANI/rGO/FR4 NEG sensor. The electrooxidation of glucose was achieved at an applied potential of 0.66 V. An anti-interferent Cu⁺²/PANI/rGO/FR4 NEG sensor demonstrated a linear response in two different glucose concentration regimes 2.8–22.2 µM and 0–4 mM with current sensitivity of 4168.37 μA mM⁻¹ cm⁻² and 525.4 μA mM⁻¹ cm⁻², respectively. The prepared sensor displayed a limit of detection (LOD) of 4.93 µM with a response time of  < 5 s. The excellent performance parameters of the Cu⁺²/PANI/rGO/FR4 NEG sensor recommend its relevance in human serum samples. These values of operating voltage, current sensitivity, linear range, LOD and anti-interference ability promise its usefulness in practical applications.