Electrochemiluminescent detection of glucose by employing a cobalt-based stainless steel electrode

Electrodes employed in the detection of glucose are commonly fabricated from conductive substances, including platinum, gold, or carbon, often modified with enzymes such as glucose oxidase, and are designed to promote electrochemical interactions that precisely quantify glucose levels in biological specimens. Cobalt-based stainless steel exhibits excellent biocompatibility and corrosion resistance and has been using in various advanced applications, such as medical devices. Herein, we demonstrate the first electroanalytical application of cobalt-based stainless steel electrode through its application for luminol electrochemiluminescence (ECL) detection of hydrogen peroxide and glucose. Luminol‑hydrogen peroxide shows intense ECL at cobalt-based stainless steel electrode, enabling the detection of H₂O₂ in the concentration range of 0.01 μM to 20 μM with a limit of detection of 1.25 nM. Moreover, intense ECL of luminol‑hydrogen peroxide at cobalt-based stainless steel electrode was used to develop an ECL glucose detection method by coupling with the enzymatic conversion of glucose to hydrogen peroxide in the presence of glucose oxidase. The developed ECL glucose detection method shows a wide linear range of 0.005 to 5 mM with a limit of detection of 0.005 mM and a limit of quantification as 0.016 mM, with excellent reproducibility (3.7 % RSD). This method was further validated through its application to real honey samples, and the results were compared by the HPLC method, showcasing its potential for glucose detection. This study implies significant potential of cobalt-based stainless steel electrode across various electroanalytical applications due to its sensitivity, wide detection range, and robustness.