Porous graphene oxide nanostructure as an excellent scaffold for label-free electrochemical biosensor: Detection of cardiac troponin I

• A sensitive method to determine cTnI cardiac biomarker by EIS method was introduced.
• Porous graphene oxide was suggested as an interesting scaffold for anti-cTnI antibody immobilization.
• Good selectivity and specificity were observed for cTnI electrochemical biosensor based on Ag-Ab interaction.
• A wide linear range of response to cTnI protein concentration with an excellent LOD was achieved.

Herein, we report the fabrication of a novel label-free impedimetric biosensor employing porous graphene oxide (PrGO) nanostructures for the specific detection of cardiac troponin-I (cTnI) to establish the myocardial infarction (MI). This nano-immunosensor demonstrates an outstanding selectivity and high sensitivity towards the human-cTnI analyte. An excellent detection limit of 0.07 ng mL− 1 and dynamic linear range of 0.1–10 ng mL− 1 were calculated for anti-cTnI/PrGO/GC. Finally, this biosensor was employed to check the concentration of the MI biomarker in real clinical samples and the results are in good agreement with standard enzyme-linked fluorescence assay (ELFA) method.