Electrochemical quantification of O-phenylphenol in citrus fruits and oilseeds using β-CD-carbon black/CuCo2O4 nanocomposite

The widespread use of toxic pesticides around the globe poses critical risks and hence it is vital to accurately quantify its residues in food samples for safeguarding human health and ensure regulatory compliance. In this work, we proposed a sensitive electrochemical platform for detection of widely used post-harvest fungicide, O-phenylphenol (OPP). To precisely detect OPP in foods, we assessed electrochemical capabilities of a screen-printed carbon electrode modified with novel nanocomposite of β-cyclodextrin/carbon black and copper cobaltite nanoflowers (βCD-CBNPs/CuCo₂O₄/SPE). The proposed electrode established strong linear correlation between peak current and analyte concentration resulting in extremely low detection limit of 0.8 nM and sensitivity of 6.55 μAμM⁻¹cm⁻². The sensor also displayed exceptional selectivity, repeatability, reproducibility, and stability highlighting its potential for use in real-world scenarios. Furthermore, the sensor displayed high OPP recovery values (96.73–100.60 %) when tested with citrus fruits (orange, pomelo, grapefruit) and oilseeds (sunflower seeds, linseed, pumpkin seeds).