Real-Time Monitoring of Insulin Using a Graphene Field-Effect Transistor Aptameric Nanosensor

5 years ago

Real-Time Monitoring of Insulin Using a Graphene Field-Effect Transistor Aptameric Nanosensor

Xuejun Wang, Qiao Lin, Scott R. Tyler, Xuezeng Zhao, Pavana G. Rotti, Yibo Zhu, Zhuang Hao, Christopher DiMarco, James Hone, John F. Engelhardt

This paper presents an approach to the real-time, label-free, specific, and sensitive monitoring of insulin using a graphene aptameric nanosensor. The nanosensor is configured as a field-effect transistor, whose graphene-based conducting channel is functionalized with a guanine-rich IGA3 aptamer. The negatively charged aptamer folds into a compact and stable antiparallel or parallel G-quadruplex conformation upon binding with insulin, resulting in a change in the carrier density, and hence the electrical conductance, of the graphene. The change in the electrical conductance is then measured to enable the real-time monitoring of insulin levels. Testing has shown that the nanosensor offers an estimated limit of detection down to 35 pM and is functional in Krebs–Ringer bicarbonate buffer, a standard pancreatic islet perfusion medium. These results demonstrate the potential utility of this approach in label-free monitoring of insulin and in timely prediction of accurate insulin dosage in clinical diagnostics.

Publisher URL: http://dx.doi.org/10.1021/acsami.7b07684

DOI: 10.1021/acsami.7b07684