An electrochemical biosensor based on hemoglobin and FeS@MoS2-C nanocomposite for nitrite, hydrogen peroxide and bromate detection

Petal-shaped FeS@MoS2-C nanocomposite was synthesized using carbon fiber as the basic carrier by hydrothermal method. The uniformly dispersed nanocomposite, hemoglobin (Hb) and Nafion mixture were drip-coated on the newly prepared carbon ionic liquid electrode (CILE) to build a modified electrode named as Nafion/Hb/FeS@MoS2-C/OLE. The morphology and valence state of FeS@MoS2C nanocomposite was investigated by SEM, TEM, XPS etc. and the biological structure of Hb was not changed based on UV-VIS and FT-IR spectroscopic analysis. Electrochemistry of Nafion/Hb/FeS@MoS2-C/OLE was recorded by cyclic voltammetry with voltammetric behaviors investigated. Also, the modified electrode has excellent catalytic performance for nitrite, hydrogen peroxide, bromate with the detection range as 0.105.00 mmol L-1, 0.10-14.00 mmol L-1, 0.05-25.00 mmol L-1, respectively. The pickle juice sample was analyzed by this method satisfactory, further proving the practical application.