Selective and sensitive Electrocatalytic behavior of hierarchical SnS decorated on La₂Sn₂O₇ embedded carbon nanofibers for detection of antioxidant diphenylamine in fruits samples

Diphenylamine (DPA) serves as an inhibitor to manage several infections and naturally occurring terpenes on fruits, which can be injurious to animals and humans. In this study, we developed tin sulfide (SnS) decorated on carbon nanofibers (CF) embedded with lanthanum stannate (La₂Sn₂O₇) and modified on glassy carbon electrodes (GCEs). Decorating the CF-LS with a SnS enhances electron transfer and introduces additional adsorption sites, facilitating the adsorption and catalytic dissociation of O₂ molecules, thereby improving target sensitivity and selectivity. The sensor exhibited remarkable electrocatalytic activity, showing cathodic peak intensities at a potential of 0.58 V and an interfacial charge transfer resistance of 19.27 Ω. It displayed broad linear range (0.0125–803.825 μM), low detection limit (0.0044 nM), and high sensitivity (1.265 μA nM⁻¹ cm⁻²). Furthermore, with relative standard deviation (RSD) of less than 2 %, the sensor showcased excellent repeatability, reproducibility, and stability. Real sample analysis of DPA in apples, red grapes, pears, and sweet tomatoes showed recovery rates (97.6–99.9 %), with an RSD below 2.5 %.