A novel ternary NiFe2O4/CuO/FeO-chitosan nanocomposite as a cholesterol biosensor

► Preparation of novel ternary NiFe2O4/CuO/FeO-chitosan nanocomposite for cholesterol sensor. ► NiFe2O4/CuO/FeO-chitosan electrode is biocompatible. ► Chitosan is used to obtain enhanced charge transfer. ► The Km (80 mg/L) (0.21 mM) value is low as compared to the reported value in literature. ► The fast response time, shelf life of about 3 months and can be used 11 times. ► The ChOx-NiFe2O4/CuO/FeO-chitosan bioelectrode can be used for estimation of cholesterol in serum samples.