Peroxidase Sensor Based on Electroactive Ce³⁺-Phytic Acid-Cu²⁺@Cu Composite

Peroxide is a vital oxidant that can quickly kill bacteria, viruses, and fungi in food and ensure food safety. However, excessive intake will stimulate the gastrointestinal tract, cause abdominal pain and vomiting, and its strong oxidation will also destroy the vitamin and protein structure in food. Cerium-based nanomaterials exhibit good biocompatibility and strong chemical stability, and have significant application value in biological detection. Cu nanoparticles were deposited on the surface of a glassy carbon electrode (GCE) by potentiostatic deposition. The Ce³⁺/PA-Cu²⁺@Cu/GCE sensor was constructed by etching and complexing Cu²⁺ with phytic acid (PA) to form a PA-Cu³⁺ coordination film. By X-ray diffraction (XRD) and Fourier Transform Infrared (FT-IR), the structure of composite material on the electrode surface was characterized. Electrochemical test results: Cu time of electrodeposition 700 s, PA embellishment 60 min, Ce³⁺ coordination 60 min, and H₂O₂ Reaction 15 min. The detection linearity range of the sensor for hydrogen peroxide is 0.1-100 μmol/L, detection limit is 0.89 μmol/L, and there was good selectivity, sensitivity and reproducibility (RSD = 1.013%) and stability (retention of 84% response at 28 days).