Highly Selective Electrochemical Sensor Based on Gadolinium Sulfide Rod-Embedded RGO for the Sensing of Carbofuran.

Nowadays, a lot of pesticides have been used in the agriculture field due to the global demand for food production. Carbofuran (CF) is the most commonly used carbamate compound that is responsible for the highest toxicity to humans compared to any other pesticide used in agricultural settings. Thus, rapid, portable, and low-cost sensors are needed for the detection of CF in the environment and food samples. Herein, we have successfully developed an electrochemical sensor using a glassy carbon electrode (GCE) modified with gadolinium sulfide (GdS) and reduced graphene oxide (RGO) composite for the detection of carbofuran (CF). A novel GdS/RGO composite was prepared by the facile hydrothermal route and confirmed by morphological and structural analyses such as field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray (EDX), powder X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS), and also the formation mechanism of GdS/RGO composite was discussed. The desired electrical conductivity of GdS was enhanced by the RGO, which was estimated from the electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Electrochemical studies demonstrated that the developed GdS/RGO sensor was highly sensitive and selective to CF. In addition, the GdS/RGO sensor exhibits a low detection limit (LOD) and the linear ranges were 0.0128 and 0.001-1381 μM, respectively, for CF detection under optimized experimental conditions. Moreover, we also investigated the practical applicability of the sensor for CF detection in the environment and food samples.