A flexible multifunctional electrode based on conducting PANI/Pd composite for non-enzymatic glucose sensor and direct alcohol fuel cell applications

In this work, we fabricated a flexible, multifunctional polyimide (PI)/Au-polyaniline (PAN)/Pd nanocomposite electrode with excellent electrochemical properties. Structural geometry, morphological views, and functional group analyses indicated that the physicochemical and electrochemical performance of the electrode is based on the strong and synergistic metal-polymer interaction between the conducting PAN and Pd, which ensured high conductivity, rapid response, and high electron transfer rate through more electroactive spots available in the nanocomposite. Here, we demonstrated that the fabricated PI/Au-PAN/Pd electrodes can be successfully used for biomedical sensing of glucose, as well as for energy conversion application, using the oxidation of alcohols such as methanol and ethanol in fuel cells. The electrochemical analysis shows that the flexible sensor (PI/Au-PAN/Pd) has ultra-high sensitivity of 2140μA/μM.cm² with a low detection limit of 0.3μM for glucose. Also, the interference analysis, reproducibility, and stability studies reveal its excellent capability for glucose sensing. Furthermore, the electrode also demonstrates prominent electrocatalytic behavior to the electrooxidation of methanol and ethanol in an alkaline medium with a current density of 3mA/cm² and 0.96mA/cm² along with good cyclic stability. Thus, this efficient flexible electrocatalyst with good stability, practicability, and reproducibility claims its potential applications in flexible/wearable healthcare diagnostics systems as well as in alternative energy conversion devices.