Sapphire-Supported Nanopores for Low-Noise DNA Sensing

Pengkun Xia, Jiawei Zuo, Shinhyuk Choi, Xiahui Chen, Jing Bai, Chao Wang

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Solid-state nanopore sensors have broad applications from single-molecule biosensing to diagnostics and sequencing. Prevalent nanopore sensors are fabricated on silicon (Si) substrates through micromachining, however, the high capacitive noise resulting from Si conductivity has seriously limited both their sensing accuracy and recording speed. A new approach is proposed here for forming nanopore membranes on insulating sapphire wafers by anisotropic wet etching of sapphire through micro-patterned triangular masks. Reproducible formation of small membranes with an average dimension of 10 μm are demonstrated. For validation, a sapphire-supported (SaS) nanopore chip, with a 100 times larger membrane area than silicon-supported (SiS) nanopore, showed 130 times smaller capacitance (10 pF) and 2.5 times smaller rootmean-square (RMS) noise current (20 pA over 100 kHz bandwidth). Tested with 1k bp double-stranded DNA, the SaS nanopore enabled sensing at microsecond speed with a signal-to-noise ratio of 21, compared to 11 from a SiS nanopore. This SaS nanopore presents a manufacturable platform feasible for biosensing as well as a wide variety of MEMS applications.

Original languageEnglish (US)
Title of host publication34th IEEE International Conference on Micro Electro Mechanical Systems, MEMS 2021
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages4
ISBN (Electronic)9781665419123
StatePublished - Jan 25 2021
Externally publishedYes
Event34th IEEE International Conference on Micro Electro Mechanical Systems, MEMS 2021 - Virtual, Gainesville, United States
Duration: Jan 25 2021Jan 29 2021

Publication series

NameProceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)
ISSN (Print)1084-6999


Conference34th IEEE International Conference on Micro Electro Mechanical Systems, MEMS 2021
Country/TerritoryUnited States
CityVirtual, Gainesville


  • MEMS
  • insulating sapphire substrates
  • low capacitance
  • low noise
  • signal-to-noise ratio
  • solid-state nanopores

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Mechanical Engineering
  • Electrical and Electronic Engineering


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