Electrochemical H₂O₂ biosensor composed of myoglobin on MoS₂ nanoparticle-graphene oxide hybrid structure

In this research, the electrochemical biosensor composed of myoglobin (Mb) on molybdenum disulfide nanoparticles (MoS₂ NP) encapsulated with graphene oxide (GO) was fabricated for the detection of hydrogen peroxide (H₂O₂). Hybrid structure composed of MoS₂ NP and GO (GO@MoS₂) was fabricated for the first time to enhance the electrochemical signal of the biosensor. As a sensing material, Mb was introduced to fabricate the biosensor for H₂O₂ detection. Formation and immobilization of GO@MoS₂ was confirmed by transmission electron microscopy, ultraviolet-visible spectroscopy, scanning electron microscopy, and scanning tunneling microscopy. Immobilization of Mb, and electrochemical property of biosensor were investigated by cyclic voltammetry and amperometric i-t measurements. Fabricated biosensor showed the electrochemical signal enhanced redox current as -1.86μA at an oxidation potential and 1.95μA at a reduction potential that were enhanced relative to those of electrode prepared without GO@MoS₂. Also, this biosensor showed the reproducibility of electrochemical signal, and retained the property until 9 days from fabrication. Upon addition of H₂O₂, the biosensor showed enhanced amperometric response current with selectivity relative to that of the biosensor prepared without GO@MoS₂. This novel hybrid material-based biosensor can suggest a milestone in the development of a highly sensitive detecting platform for biosensor fabrication with highly sensitive detection of target molecules other than H₂O₂.