Reduced graphene oxide biosensor platform for the detection of NT-proBNP biomarker in its clinical range.

Reduced graphene oxide (rGO) thin films can be exploited as highly sensitive transducer layers and integrated in interdigital micro-electrode systems for biosensing processes. The distinctive bipolar characterisitics of rGO thin films can be modulated by a very low external electric field due to the electrostatic charges of biomolecules. These charges lead to a fast response in the readout signals of rGO based ion sensitive field-effect transistors (ISFETs). The characterisitc changes of rGO ISFETs enable a fast, accurate and reproducible detection of biomolecules. The biosensing mechanism offers a fast and label-free approach for analyte detection in contrast to the classical ELISA method. In this contribution, we introduce a reproducible fabrication process of rGO based field-effect transistors on wafer level. The sensors are functionalized as biosensors to measure N-terminal pro-brain natriuretic peptide (NT-proBNP) in human serum within its clinical range. Our optimized rGO sensor shows very promising electrical properties and can be considered as a proof of concept study for the detection of various analytes. The easy and cost-effective fabrication as well as the versatile usability make this new technological platform an auspicious tool for different sensing applications in future.