A glassy carbon electrode modified with FeS nanosheets as a highly sensitive amperometric sensor for hydrogen peroxide

Iron sulfides with different atomic ratios were synthesized by a hydrothermal method and used to modify a glassy carbon electrode. The various sulfides were compared to each other for their amperometric response to H 2 O 2 . It is found that FeS is the most adequate material. Operated in 0.1 M NaOH solution at 0.4 V (vs. Ag/AgCl), the sensor based on FeS displays a linear response that extends from 0.50 μM to 20.5 mM of H 2 O 2 , with a sensitivity of 36.4 μA mM −1  cm −2 and a detection limit of 0.15 μM (at an S/N ratio of 3). The sensor is selective, stable and reproducible. Schematic of the synthesis of pomegranate flower-like FeS by a hydrothermal route using ferric chloride and thiourea (SC(NH 2 ) 2 ) as the precursors, and ethanolamine (EA) as the structure-guiding auxiliary agent. A glassy carbon electrode (GCE) modified with this material allows for amperometric sensing of hydrogen peroxide in 0.1 M NaOH solution with a 0.15 μM detection limit.