Voltammetric nano-molar range quantification of agrochemical pesticide using needle-like strontium pyrophosphate embedded on sulfur doped graphitic carbon nitride electrocatalyst

•The SrPO/SCN nanocomposite has been successfully synthesized via a simple precipitation method.•SrPO/SCN/GCE successfully applied for trace level detection of diphenylamine.•The electrocatalyst achieved low detection limit (0.009 µM) and dynamic linear range (0.05–98 µM)•The electrocatalyst shows good stability, repeatability and reproducibility.•The proposed SrPO/SCN/GCE reveals very good recoveries in food samples. The development of a viable sensor for agrochemical pesticides requires the assessment of trace levels. To achieve this, we developed a diphenylamine (DPA) sensor using needle-like strontium pyrophosphate embedded in sulfur-doped graphitic carbon nitride (SrPO/SCN). We obtained needle-like SrPO/SCN nanocomposite through co-precipitation followed by ultrasonication. The formation of the SrPO/SCN nanocomposite was verified through FT-IR, XRD, XPS, SEM-EDX, and HR-TEM analyses. Additionally, we explored their electrochemical behavior towards DPA using differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The SrPO/SCN nanocomposite-modified electrode exhibited a higher anodic peak current (15.47 µA) than those of the other modified and unmodified electrodes. Under optimal experimental conditions, SrPO/SCN/GCE demonstrated a good limit of detection (0.009 µmol/L), dynamic linear range (0.05–98 µmol/L), and sensitivity (0.36 µAµM-1cm−2). Furthermore, the developed sensor exhibited excellent reproducibility, selectivity, and stability, and successfully detected DPA in real samples, including pear and apple samples, with good recoveries.