In situ developed NiCo2O4–Ti3C2Tx nanohybrid towards non-enzymatic electrochemical detection of glucose and hydrogen peroxide

Abstract

Owing to the adverse consequences of excess glucose (Glu) and hydrogen peroxide (H₂O₂) on humans, it is imperative to develop an electrochemical sensor for detection of these analytes with good selectivity and sensitivity. Herein, a nanohybrid comprising nickel cobaltite nanoparticles (NiCo₂O₄ NPs) embedded on conductive Ti₃C₂T_x nanosheets (NSs) has been prudently designed and employed for the electrochemical detection of Glu and H₂O₂. The developed nanohybrid has been systematically characterized using morphological and spectral techniques, and then immobilized on a glassy carbon electrode (GCE). Under optimized conditions, the developed NiCo₂O₄–Ti₃C₂T_x/GCE based electrochemical sensor has demonstrated an impressive analytical response towards Glu and H₂O₂ with good sensitivity and selectivity. The non-enzymatic sensor has demonstrated a broad linear range from 30 μM to 1.83 mM for Glu, and two linear ranges of 20–100 μM and 100 μM–2.01 mM for H₂O₂. The sensor has exhibited limits of detection (LOD) of 9 μM and 6 μM with sensitivities of 101.2 μA μM⁻¹ cm⁻² and 107.03 μA μM⁻¹ cm⁻², respectively, for Glu and H₂O₂ detection. The impressive analytical performance of the fabricated sensor in terms of linear range, LOD and sensitivity are ascribed to the (i) enhanced conductivity of Ti₃C₂T_x NSs, (ii) mediated electrocatalytic activity of NiCo₂O₄ NPs and (iii) large number of catalytically active sites on the NiCo₂O₄–Ti₃C₂T_x heterostructure. Notably, the NiCo₂O₄–Ti₃C₂T_x/GCE has demonstrated impressive stability and reproducibility, which is mainly due to the in situ uniform growth of NiCo₂O₄ NPs over Ti₃C₂T_x NSs.