Amperometric biosensor based on hemoglobin immobilized on Cu2S nanorods/nafion nanocomposite film for the determination of polyphenols

A novel biosensor was fabricated based on hemoglobin (Hb) immobilized onto cuprous sulfide (Cu₂S) nanorods/nafion nanocomposite film for the detection of polyphenols in the presence of hydrogen peroxide (H₂O₂). The nanostructured inorganic–organic hybrid material formed by Cu₂S nanorods and nafion provided a biocompatible microenvironment for Hb and increased the sensitivity for polyphenols detection. The modified electrodes were characterized by electrochemical impedance spectroscopy and linear sweep voltammetry. Parameters such as pH, H₂O₂ concentration, and the applied potential were optimized. Under optimum conditions, the biosensor gave linear response ranges of 7.0–110, 0.6–10, and 8–100 μM for catechol, hydroquinone, and resorcin, with the detection limits of 0.5, 0.03, and 0.6 μM (S/N?=?3), respectively. The developed biosensor exhibited a short response time within only 8 s with good stability and reproducibility. Such a novel biosensor showed great promise for rapid, simple analysis of polyphenols contents in real samples.