Oxide-on-graphene field effect bio-ready sensors

作     者：Bei Wang Kristi L. Liddell Junjie Wang Brandon Koger Christine D. Keating Jun Zhu 

作者机构：Department of Physics The Pennsylvania State University University Park Pennsylvania 16802 USA Department of Chemistry The Pennsylvania State University University Park Pennsylvania 16802 USA Materials Research Institute The Pennsylvania State University University Park Pennsylvania 16802 USA 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2014年第7卷第9期

页      面：1263-1270页

核心收录：

学科分类：080503[工学-材料加工工程] 0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080202[工学-机械电子工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 0702[理学-物理学] 

基　　金：supported by the US National Science Foundation Nanoscale Interdisciplinary Research Team (NSF NIRT) Materials Research Science and Engineering Centers (MRSEC) CAREER grant 

主　　题：graphene biosensor pH sensor ISFET APTMS label-free 

摘      要：Electrical detection schemes using nanoscale devices offer fast and label-free alternatives to biosensing techniques based on chemical and optical interactions. Here we report on the design, fabrication, and operation of oxide-on-graphene ion-sensitive field effect sensor arrays using large-area graphene sheets synthesized by chemical vapor deposition. In this scheme, HfO2 and SiO2 thin films are deposited atop the graphene sheet and play the dual role of the sensing interface, as well as the passivation layer protecting the channel and electrodes underneath from direct contact with the electrolyte. We further demonstrate the functionalization of the SiO2 surface with 3-aminopropyltrimethoxysilane （APTMS）. The oxide-on-graphene sensors operate in solution with high stability and a high average mobility of 5,000 cm2/（V＇s）. As a proof of principle, we demonstrate pH sensing using the bare or the APTMS-functionalized SiO2 as the sensing surface. The measured sensitivities, 46 mV/pH and 43 mV/pH, respectively, agree well with existing studies. We further show that by applying the solution gate voltage in pulse, the hysteresis in the transfer curve of the graphene transducer can be eliminated, greatly improving the ionic potential resolution of the sensor. These experiments demonstrate the potential of oxide-on-graphene ion-sensitive field effect sensors in on-chip, label-free and real-time biosensing applications.