Maheshwaran_2026_Environ.Res__124768

Methyl parathion (MPT), an organophosphorus pesticide, is widely used in agriculture for the protection of crops. However, the residual toxicity of MPT causes severe health issues by inhibiting acetylcholinesterase, leading to neurological disorders. Therefore, the development of sensitive and reliable detection methods is essential for food safety. In this work, a novel 3D-2D Type-II Pr(2)S(3)/Bi(2)S(3)@GO heterojunction composite was successfully synthesized using a hydrothermal method, integrating the strong electrocatalytic activity of Pr(2)S(3)/Bi(2)S(3) with the porous structure of graphene oxide (GO). The composite was characterized using XRD, FE-SEM, TEM, and XPS, confirming its crystal phase, morphology, and elemental composition. Electrochemical measurements were performed using Pr(2)S(3)/Bi(2)S(3)@GO-modified GCE in 0.1 M phosphate buffer solution (pH 7). The fabricated sensor demonstrated a wide linear detection range (0.01-1124 microM), high sensitivity (1.423 microA microM(-1) cm(-2)), and an ultralow detection limit of 2.9 nM. The sensor also exhibited excellent selectivity among various interfering species, good repeatability, and long-term stability (RSD < 5 %). The practical performance was verified by the detection of MPT in river water, apple, and cabbage, yielding an excellent recovery value (97.12-99.64 %). Overall, these results highlight the Pr(2)S(3)/Bi(2)S(3)@GO as a promising and cost-effective sensing platform for precise and reliable monitoring of pesticide residue in environmental and food samples.