Cholesterol immobilization on chemical vapor deposition grown graphene nanosheets for biosensors and bioFETs with enhanced electrical performance

The intensive bio-effects on graphene surface is an attention-grabbing field which determine the capability of performing rapid detection of biomolecules with high accuracy. Here, we report the electrical performance of graphene devices with the immobilization of cholesterol molecules. In electrical transport measurements, the Dirac point position is gradually shifted towards negative gate voltage as cholesterol concentration increases which reveals the clear influence of cholesterol molecules on the graphene. This graphene surface modifications induce n-type doping and the charge carrier mobility is increased from similar to 2000 cm(2)V(-1)s(-1) to similar to 3900 cm(2)V(-1)s(-1) by increasing the cholesterol concentration. The detection of cholesterol molecules is further investigated by Raman spectroscopy, FTIR and AFM characterizations. The results indicate significant impact of cholesterol-graphene interaction on the performance of graphene devices. Furthermore, sensing approach can be quantitatively deployed for commercial use of portable graphene-based cholesterol sensing devices for biomedical applications. (C) 2017 Elsevier B.V. All rights reserved.