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

- Intensive effects of cholesterol-graphene interaction on the graphene surface.
- Graphene surface modifications induce n-type doping and boost-up the charge carrier mobility.
- Cholesterol immobilization on graphene surface improves the overall electrical performance of devices.
- Graphene-based sensors show linear response to determine the cholesterol concentration in a rapid and efficient mode with high accuracy.

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 ∼2000 cm2 V−1 s−1 to ∼3900 cm2 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.

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