This title appears in the Scientific Report : 2017 

Biosensing near the neutrality point of graphene
Fu, Wangyang (Corresponding author)
Feng, Lingyan / Panaitov, Gregory / Kireev, Dmitry / Mayer, Dirk / Offenhäusser, Andreas / Krause, Hans-Joachim
Bioelektronik; ICS-8
Science advances, 3 (2017) 10, S. e1701247 -
Washington, DC [u.a.] Assoc. 2017
Journal Article
Controlling Configuration-Based Phenomena
Physical Basis of Diseases
Engineering Cell Function
Please use the identifier: in citations.
Please use the identifier: in citations.
Over the past decade, the richness of electronic properties of graphene has attracted enormous interest for electrically detecting chemical and biological species using this two-dimensional material. However, the creation of practical graphene electronic sensors greatly depends on our ability to understand and maintain a low level of electronic noise, the fundamental reason limiting the sensor resolution. Conventionally, to reach the largest sensing response, graphene transistors are operated at the point of maximum transconductance, where 1/f noise is found to be unfavorably high and poses a major limitation in any attempt to further improve the device sensitivity. We show that operating a graphene transistor in an ambipolar mode near its neutrality point can markedly reduce the 1/f noise in graphene. Remarkably, our data reveal that this reduction in the electronic noise is achieved with uncompromised sensing response of the graphene chips and thus significantly improving the signal-to-noise ratio—compared to that of a conventionally operated graphene transistor for conductance measurement. As a proof-of-concept demonstration of the usage of the aforementioned new sensing scheme to a broader range of biochemical sensing applications, we selected an HIV-related DNA hybridization as the test bed and achieved detections at picomolar concentrations.