Electroanalysis of metronidazole using exfoliated MoS2 sheets and electrodeposited amorphous MoSx

Molybdenum disulfide, MoS2, sheets were obtained by exfoliation of the bulk powders in an aqueous solution containing 1.0 mM tryptophan and then drop-cast onto a glassy carbon electrode to give GCE/MoS2. For comparative purposes, amorphous MoSx was electrodeposited directly onto the glassy carbon electrode from a 5 mM (NH4)2MoS4 solution. Both electrodes were employed in the electrochemical detection of the antibiotic metronidazole (MTZ). While the MTZ was reduced at both modified surfaces, the GCE/MoS2 was superior and this was attributed to a higher surface area, a lower charge-transfer resistance and to the presence of edges and defects in the sheets that facilitate the electron transfer reaction.