GrapheneTransistors with Multifunctional PolymerBrushes for Biosensing Applications

Abstract

Exhibiting\na combination of exceptional structural and electronic\nproperties, graphene has a great potential for the development of\nhighly sensitive sensors. To date, many challenging chemical, biochemical,\nand biologic sensing tasks have been realized based on graphene. However,\nmany of these sensors are rather unspecific. To overcome this problem,\nfor instance, the sensor surface can be modified with analyte-specific\ntransducers such as enzymes. One problem associated with the covalent\nattachment of such biomolecular systems is the introduction of crystal\ndefects that have a deleterious impact on the electronic properties\nof the sensor. In this work, we present a versatile platform for biosensing\napplications based on polymer-modified CVD-grown graphene transistors.\nThe functionalization method of graphene presented here allows one\nto integrate several functional groups within surface-bound polymer\nbrushes without the introduction of additional defects. To demonstrate\nthe potential of this polymer brush functionalization scaffold, we\nmodified solution-gated graphene field-effect transistors with the\nenzyme acetylcholinesterase and a transducing group, allowing the\ndetection of the neurotransmitter acetylcholine. Taking advantage\nof the transducing capability of graphene transistors and the versatility\nof polymer chemistry and enzyme biochemistry, this study presents\na novel route for the fabrication of highly sensitive, multipurpose\ntransistor sensors that can find application for a multitude of biologically\nrelevant analytes.