Defect-Mediated Molecular Interaction and Charge Transfer in Graphene Mesh-Glucose Sensors

Sun Sang Kwon, Jae Hyeok Shin, Jonghyun Choi, Sungwoo Nam, Won Il Park

Research output: Contribution to journalArticlepeer-review

Abstract

We report the role of defects in enzymatic graphene field-effect transistor sensors by introducing engineered defects in graphene channels. Compared with conventional graphene sensors (Gr sensors), graphene mesh sensors (GM sensors), with an array of circular holes, initially exhibited a higher irreversible response to glucose, involving strong chemisorption to edge defects. However, after immobilization of glucose oxidase, the irreversibility of the responses was substantially diminished, without any reduction in the sensitivity of the GM sensors (i.e., -0.53 mV/mM for the GM sensor vs -0.37 mV/mM for Gr sensor). Furthermore, multiple cycle operation led to rapid sensing and improved the reversibility of GM sensors. In addition, control tests with sensors containing a linker showed that sensitivity was increased in Gr sensors but decreased in GM sensors. Our findings indicate that edge defects can be used to replace linkers for immobilization of glucose oxidase and improve charge transfer across glucose oxidase-graphene interfaces.

Original languageEnglish (US)
Pages (from-to)14216-14221
Number of pages6
JournalACS Applied Materials and Interfaces
Volume9
Issue number16
DOIs
StatePublished - Apr 26 2017

Keywords

  • edge functionalization
  • enzymatic sensor
  • graphene
  • graphene mesh
  • multiple cycle operation

ASJC Scopus subject areas

  • Materials Science(all)

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