Detection of heart failure-related biomarker in whole blood with graphene field effect transistor biosensor

Since brain natriuretic peptide (BNP) has become internationally recognized biomarkers in the diagnosis and prognosis of heart failure (HF), it is highly desirable to search for a novel sensing tool for detecting the patient's BNP level at the early stage. Here we report a platinum nanoparticles (PtNPs)-decorated reduced graphene oxide (rGO) field effect transistor (FET) biosensor coupled with a microfilter system for label-free and highly sensitive detection of BNP in whole blood. The PtNPs-decorated rGO FET sensor was obtained by drop-casting rGO onto the pre-fabricated FET chip and subsequently assembling PtNPs on the graphene surface. After anti-BNP was bound to the PtNPs surface, BNP was successfully detected by the anti-BNP immobilized FET biosensor. It was found that the developed FET biosensor was able to achieve a low detection limitation of 100 fM. Moreover, BNP was successfully detected in human whole blood sample treated by a custom-made microfilter, suggesting the sensor's capability of working in a complex sample matrix. The developed FET biosensor provides a new sensing platform for protein detection, showing its potential applications in clinic sample.