Antibody functionalized graphene biosensor for label-free electrochemical immunosensing of fibrinogen, an indicator of trauma induced coagulopathy

An antibody, specific to fibrinogen, has been covalently attached to graphene and deposited onto screen printed electrodes using a chitosan hydrogel binder to prepare an inexpensive electrochemical fibrinogen biosensor. Fourier Transform Infrared (FT-IR) spectroscopy has been utilized to confirm the presence of the antibody on the graphene scaffold. Electrochemical Impedance Spectroscopy (EIS) has been utilized to demonstrate that the biosensor responds in a selective manner to fibrinogen in aqueous media even in the presence of plasminogen, a potentially interfering molecule in the coagulopathy cascade. Furthermore, the biosensor was shown to reliably sense fibrinogen in the presence of high background serum albumin levels. Finally, we demonstrated detection of clinically relevant fibrinogen concentrations (938-44,542 μg/dL) from human serum and human whole blood samples using this biosensor. This biosensor can potentially be used in a point-of-care device to detect the onset of coagulopathy and monitor response following therapeutic intervention in trauma patients. Thus this biosensor may improve the clinical management of patients with trauma-induced coagulopathy.