Fully integrated graphene electronic biosensor for label-free detection of lead (II) ion based on G-quadruplex structure-switching.
This work presents a fully integrated graphene field-effect transistor (GFET) biosensor for the label-free detection of lead ions (Pb2+) in aqueous-media, which first implements the G-quadruplex structure-switching biosensing principle in graphene nanoelectronics. We experimentally illustrate the biomolecular interplay that G-rich DNA single-strands with one-end confined on graphene surface can specifically interact with Pb2+ions and switch into G-quadruplex structures. Since the structure-switching of electrically charged DNA strands can disrupt the charge distribution in the vicinity of graphene surface, the carrier equilibrium in graphene sheet might be altered, and manifested by the conductivity variation of GFET. The experimental data and theoretical analysis show that our devices are capable of the label-free and specific quantification of Pb2+with a detection limit down to 163.7ng/L. These results first verify the signaling principle competency of G-quadruplex structure-switching in graphene electronic biosensors. Combining with the advantages of the compact device structure and convenient electrical signal, a label-free GFET biosensor for Pb2+monitoring is enabled with promising application potential.
Center for Sensor Technology of Environment and Health, Tsinghua University, Beijing 100084, China; State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Yijun
Y
Li
Center for Sensor Technology of Environment and Health, Tsinghua University, Beijing 100084, China; State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: cwang@tsinghua.edu.cn.
Cheng
C
Wang
Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA.
Yibo
Y
Zhu
Center for Sensor Technology of Environment and Health, Tsinghua University, Beijing 100084, China; State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Xiaohong
X
Zhou
Department of Chemistry, Tsinghua University, Beijing 100084, China.
Yu
Y
Xiang
Center for Sensor Technology of Environment and Health, Tsinghua University, Beijing 100084, China; State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Miao
M
He
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: szeng@tsinghua.edu.cn.
Siyu
S
Zeng
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002413:Cations, Divalent / Q000032:analysis; D004247:DNA / Q000737:chemistry*; D004867:Equipment Design; D054856:G-Quadruplexes; D006108:Graphite / Q000737:chemistry*; D007854:Lead / Q000032:analysis*; D057230:Limit of Detection; D014173:Transistors, Electronic; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
D002413:Cations, Divalent; D014874:Water Pollutants, Chemical; D014867:Water; D007854:Lead; D006108:Graphite; D004247:DNA
Fully integrated biosensor; G-quadruplex; Graphene field-effect transistor; Lead (II) ion; Structure-switching signaling