Synthesis and Characterization of Samarium-Substituted Molybdenum Diselenide and Its Graphene Oxide Nanohybrid for Enhancing the Selective Sensing of Chloramphenicol in a Milk Sample.

The electronic conductivity and electrocatalytic activity of metal chalcogenides are normally enhanced by following the ideal strategies such as substitution/doping of heterogeneous atoms and hybridization of highly conductive carbon supportive materials. Here, a rare earth element (samarium) was substituted with MoSe2 using the simple hydrothermal method. The lattice distortion due to the substitution of Sm3+ with MoSe2 was clearly observed by using high-resolution transmission electron microscopy analysis. As a consequence, the prepared SmMoSe2 nanorod was encapsulated with graphene oxide (GO) sheets by using ultrasonication process. Furthermore, the GO-encapsulated SmMoSe2 nanocomposite modified glassy carbon electrode (GO@SmMoSe2/GCE) was used for the sensing of chloramphenicol. The results showed that the GO@SmMoSe2/GCE revealed the superior electrocatalytic activity with low detection (5 nM) and sensitivity (20.6 μA μM-1 cm-2) to electrochemical detection of proposed analyte. It indicates that the substitution of Sm3+ and encapsulation of GO significantly increased both the electrical conductivity and electrocatalytic activity of MoSe2.