Introducing a portable electrochemical biosensor for Mycobacterium avium subsp. paratuberculosis detection using graphene oxide and chitosan

Characterization of graphene oxide nanoparticles (GO)

Initially, the as-prepared graphene oxide nanoparticles were characterized by imaging method using Scanning Electron Microscopy (SEM) (TESCAN-Vega3 Brno, Czech Republic). In this regard, the SEM image of the as-prepared graphene oxide nanoparticles was recorded (Figure s1). The results revealed that the prepared graphene oxide nanoparticles have a size distribution of over 80–215 nm with an average size of 160 nm.

In addition, the crystalline properties of the as-prepared GO were evaluated by patterned X-ray diffraction (XRD) d8…