A novel electrochemical sensor based on mixed cubic and spherical Cu₂O composited with MWCNTs-COOH for sensitive...

The use of Cu₂O for construction of efficient electrochemical sensors has become a hot research topic. The morphology and structure of Cu₂O nanoparticles have an important influence on their catalytic performance. Mixed cubic and spherical Cu₂O particles were prepared by a chemical reduction method, which were then composited with carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) through a facile ultrasonic treatment. Cu₂O/MWCNTs-COOH composite was modified onto glassy carbon electrode (GCE) to construct a novel sensor (Cu₂O/MWCNTs-COOH/GCE) for highly sensitive detection of acetaminophen (APAP). Under the optimized experimental conditions, Cu₂O/MWCNTs-COOH/GCE exhibits a wide linear range (1-200 μM), high sensitivity (1.022 μA/μM), low detection limit (LOD, 3σ/k, 0.25 μM), great anti-interference property, reproducibility, repeatability, and stability for APAP detection. The practical applicability of Cu₂O/MWCNTs-COOH/GCE was verified by determining APAP in commercial tablets (recoveries: 96.0 %-104.7 %) and spiked human serum samples (recoveries: 94.0 %-104.0 %).