Electrochemical Determination of Acetaminophen and Amoxicillin Using CuO/Graphitic Carbon Nitride Hybrid Composite Modified Electrode

Acetaminophen (PCM) and amoxicillin (AMX) are commonly used drugs, but their overuse and environmental release pose risks to human health and ecosystems. A simple sensor based on a 2D hybrid composite of copper oxide and graphitic carbon nitride (CuO/GCN) was developed to detect PCM and AMX. The CuO/GCN sensor material was synthesized using hydrothermal and sonochemical methods and characterized by UV–visible spectroscopy, Fourier transform infrared spectroscopy, high-resolution scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction. Electrochemical detection was performed with cyclic voltammetry and amperometric techniques. The sensor showed high sensitivity with detection limits of 6.8 nM for PCM and 12.9 nM for AMX, with broad linear ranges of 0.025–939.15 μM for PCM and 0.025–8.55 μM for AMX in PBS at pH 7.4. It demonstrated excellent repeatability, reproducibility, and selectivity. The sensor was successfully applied to tap water and human urine, showing high recovery rates of 98.8%–102.0% for PCM and 100.7%–104.7% for AMX. This CuO/GCN sensor shows potential for pharmaceutical analysis and environmental monitoring.