An aptameric graphene nanosensor for label-free detection of small-molecule biomarkers

Cheng Wang, Jinho Kim, Yibo Zhu, Jaeyoung Yang, Gwan Hyoung Lee, Sunwoo Lee, Jaeeun Yu, Renjun Pei, Guohua Liu, Colin Nuckolls, James Hone, Qiao Lin

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)222-229
Number of pages8
JournalBiosensors and Bioelectronics
Volume71
DOIs
Publication statusPublished - 2015 Sep 5

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry

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