An aptameric graphene nanosensor for label-free detection of small-molecule biomarkers.
This paper presents an aptameric graphene nanosensor for detection of small-molecule biomarkers. To address difficulties in direct detection of small molecules associated with their low molecular weight and electrical charge, we incorporate an aptamer-based competitive affinity assay in a graphene field effect transistor (FET), and demonstrate the utility of the nanosensor with dehydroepiandrosterone sulfate (DHEA-S), a small-molecule steroid hormone, as the target analyte. In the competitive affinity assay, DHEA-S specifically binds to aptamer molecules pre-hybridized to their complementary DNA anchor molecules immobilized on the graphene surface. This results in the competitive release of the strongly charged aptamer from the DNA anchor and hence a change in electrical properties of the graphene, which can be measured to achieve the detection of DHEA-S. We present experimental data on the label-free, specific and quantitative detection of DHEA-S at clinically appropriate concentrations with an estimated detection limit of 44.7 nM, and analyze the trend observed in the experiments using molecular binding kinetics theory. These results demonstrate the potential of our nanosensor in the detection of DHEA-S and other small molecules in biomedical applications.
Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA; Department of Microelectronic Engineering, Nankai University, Tianjin 300071, China.
Cheng
C
Wang
Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA.
Jinho
J
Kim
Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA.
Yibo
Y
Zhu
Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA.
Jaeyoung
J
Yang
Department of Materials Science and Engineering, Yonsei University, Seoul 120749, Republic of Korea.
Gwan-Hyoung
GH
Lee
Department of Electrical Engineering, Columbia University, New York, NY 10027, USA.
Sunwoo
S
Lee
Department of Chemistry, Columbia University, New York, NY 10027, USA.
Jaeeun
J
Yu
Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu 215123, China.
Renjun
R
Pei
Department of Microelectronic Engineering, Nankai University, Tianjin 300071, China.
Guohua
G
Liu
Department of Chemistry, Columbia University, New York, NY 10027, USA.
Colin
C
Nuckolls
Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA.
James
J
Hone
Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA. Electronic address: qlin@columbia.edu.
Qiao
Q
Lin
D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001483:Base Sequence; D015374:Biosensing Techniques / Q000295:instrumentation*; D019314:Dehydroepiandrosterone Sulfate / Q000032:analysis*; D004867:Equipment Design; D006108:Graphite / Q000737:chemistry*; D056656:Lab-On-A-Chip Devices; D057230:Limit of Detection
D052157:Aptamers, Nucleotide; D019314:Dehydroepiandrosterone Sulfate; D006108:Graphite
Aptamer; Competitive assay; Dehydroepiandrosterone sulfate (DHEA-S); Graphene; Nanobiosensor; Small molecule