Surface engineering of samarium stannate–polyimide via laser-assisted graphenization for enhanced electrochemical detection of fenamiphos

Abstract

The increasing use of pesticides poses significant threats to both the environment and human health. Safety assessments for controlling or monitoring such potential hazards require on-site sensing devices with facile fabrication and ultralow detection limits. In particular, electrochemical assays satisfy some of these requirements; however, to date, their electrodes have not demonstrated satisfactory stability, selectivity, or sensitivity. This paper reports the development of a simple, efficient electrochemical sensor based on a composite of samarium stannate (Sm2Sn2O7) and laser-induced graphene (LIG) for detecting fenamiphos (FNPS) insecticides in environmental and food samples. A laser photothermal reaction was employed to simultaneously carbonize and amorphize the surface of a Sm2Sn2O7–polyimide film. This single-step reaction furnished a three-dimensional porous LIG network with Sm2Sn2O7 clusters. The resulting Sm2Sn2O7–LIG nanocomposite exhibited enhanced physicochemical properties, surpassing those of its individual components, i.e., LIG and Sm2Sn2O7. Moreover, a glassy carbon electrode modified with Sm2Sn2O7–LIG was employed for the detection of FNPS at remarkably low concentrations of 7.69 nM, exhibiting a high sensitivity of 1.5137 µA µM−1cm−2. Real-time monitoring resulted in a recovery rate of more than 96 % from spiked environmental and food samples, confirming its practical applicability for sensitive FNPS detection.