Single-walled carbon nanotubes (SWCNTs) hold vast potential for future electronic devices due to their outstanding properties, however covalent functionalization often destroys the intrinsic properties of SWCNTs, thus limiting their full potential. Here, we demonstrate the fabrication of a functionalized graphene/semiconducting SWCNT (T@fG) heterostructured thin film transistor as a chemical sensor. In this structural configuration, graphene acts as an atom-thick, impermeable layer that can be covalently functionalized via facile diazonium chemistry to afford a high density of surface functional groups while protecting the underlying SWCNT network from chemical modification, even during a covalent chemical reaction. As a result, the highly functionalized carbon-based hybrid structure exhibits excellent transistor properties with a carrier mobility and ON/OFF ratio as high as 64 cm2/Vs and 5400, respectively. To demonstrate its use in potential applications, T@fG thin films were fabricated as aqueous ammonium sensors exhibiting a detection limit of 0.25 μM in a millimolar ionic strength solution, which is comparable with state-of-the-art aqueous ammonium nanosensors.

中文翻译：

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石墨烯作为半导体碳纳米管晶体管传感器的功能层

单壁碳纳米管 (SWCNT) 由于其出色的特性而在未来的电子设备中具有巨大的潜力，但是共价功能化通常会破坏 SWCNT 的固有特性，从而限制了它们的全部潜力。在这里，我们展示了功能化石墨烯/半导体 SWCNT (T@fG) 异质结构薄膜晶体管作为化学传感器的制造。在这种结构配置中，石墨烯充当一个原子厚的不渗透层，可以通过简单的重氮化学共价功能化，以提供高密度的表面官能团，同时保护底层 SWCNT 网络免受化学改性，即使在共价化学反应期间也是如此。因此，高度功能化的碳基混合结构表现出优异的晶体管特性，载流子迁移率和开/关比分别高达 64 cm2/Vs 和 5400。为了证明其在潜在应用中的应用，T@fG 薄膜被制造为水性铵传感器，在毫摩尔离子强度溶液中的检测限为 0.25 μM，可与最先进的水性铵纳米传感器相媲美。