Graphene-gated biochip for the detection of cardiac marker Troponin I

•One step lithium ion intercalation mediated exfoliation process for preparing monolithic graphene sheets.•A micro-device in the drain-source configuration using gold electrodes on a silicon chip.•The label free detection of cardiac biomarker, Troponin I.•Detection limit <0.1 pg mL−1 for Troponin I.

We report lithium ion intercalation mediated efficient exfoliation of graphite to form monolithic graphene sheets which have subsequently been investigated for the development of highly sensitive label-free electrochemical detection platform for cardiac biomarker, Troponin I (cTnI). The spectroscopic and morphological analysis demonstrated the formation of defect free graphene sheets which were successfully employed to fabricate an inter-digited microdevice in a drain-source configuration on a silicon biochip. The graphene gated biochip functionalized with anti-cTnI antibodies used in label free detection of cTnI which exhibited an excellent sensitivity in the picogram range (∼1 pg mL−1) for cTnI without the use of any enzymatic amplification that promises its potential applicability for bio-molecular detection in clinical diagnosis.

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