• 文献标题:   Dielectric-Modulated Biosensing with Ultrahigh-Frequency-Operated Graphene Field-Effect Transistors
  • 文献类型:   Article
  • 作  者:   ZHANG XY, LIU TX, BOYLE A, BAHREMAN A, BAO L, JING QS, XUE HL, KIELTYKA R, KROS A, SCHNEIDER GF, FU WY
  • 作者关键词:   dielectric modulation, field effect, graphene biosensor, ionic screening, ultrahigh frequency
  • 出版物名称:   ADVANCED MATERIALS
  • ISSN:   0935-9648 EI 1521-4095
  • 通讯作者地址:  
  • 被引频次:   9
  • DOI:   10.1002/adma.202106666 EA JAN 2022
  • 出版年:   2022

▎ 摘  要

Owing to their excellent electrical properties and chemical stability, graphene field-effect transistors (Gr-FET) are extensively studied for biosensing applications. However, hinging on surface interactions of charged biomolecules, the sensitivity of Gr-FET is hampered by ionic screening under physiological conditions with high salt concentrations up to frequencies as high as MHz. Here, an electrolyte-gated Gr-FET in reflectometry mode at ultrahigh frequencies (UHF, around 2 GHz), where the ionic screening is fully cancelled and the dielectric sensitivity of the device allows the Gr-FET to directly function in high-salt solutions, is configured. Strikingly, by simultaneous characterization using electrolyte gating and UHF reflectometry, the developed graphene biosensors offer unprecedented capability for real-time monitoring of dielectric-specified biomolecular/cell interactions/activities, with superior limit of detection compared to that of previously reported nanoscale high-frequency sensors. These achievements highlight the unique potential of ultrahigh-frequency operation for unblocking the true potential of graphene biosensors for point-of-care diagnostic.