Monitoring amyloid-β 42 conformational change using a spray-printed graphene electrode

[Display omitted] •Development of highly reproducible spray-printed graphene electrochemical sensors.•Use of spray-printed graphene sensors to monitor amyloid-β 42 aggregation.•This represents a potential complementary technique for studying protein aggregation. Up to now, the reproducibility and stability of graphene-based electrochemical sensors have represented an obstacle to the development of practical biosensing techniques. In this paper we report a cost-effective and highly reproducible graphene-based electrochemical sensing platform to monitor the kinetic conformational change of amyloidogenic proteins. The sensor surface is spray-printed with a graphene oxide layer and then electrochemically reduced to achieve excellent sensitivity to the redox current. The reproducibility of these sensors in terms of redox peak position, intensity and electroactive area has been proved to be high. These sensors are used to monitor the conformational changes of amyloid-β 42 via the change in the oxidation current of tyrosine, which is caused by different electrochemical accessibility during the aggregation process. The aggregation process detected at these graphene electrochemical sensors shows a good correlation with the fluorescence assay. The proposed platform provides a complementary technique to aid understanding of the detailed process of amyloidogenic protein aggregation and the mechanism of neurodegenerative diseases as well as helping to promote the development of disease-prevention strategies.