Impedance sensing of DNA immobilization and hybridization by microfabricated alumina nanopore membranes

Songmei Wu, Weiwei Ye, Mo Yang, Mojtaba Taghipoor, Robert Meissner, Juergen Brugger, Philippe Renaud

Research output: Journal article publicationJournal articleAcademic researchpeer-review

17 Citations (Scopus)


In this work we demonstrate microfabricated thin alumina nanopore membranes as a platform for impedance sensing of DNA immobilization and hybridization. We develop a wafer-scale fabrication of free-standing alumina nanopore membranes with well controlled thickness, pore diameter and overall pore density. One 1 cm × 1 cm single chip contains an array of 69 membranes. Each membrane is 100 μm × 100 μm large and 2 μm thick, with pore diameter of 120 nm. With low pore density of ∼6 pores/μm2, nanopore resistance and membrane capacitance can be recognized clearly in the electrochemical impedance spectrum from 100 to 1 MHz. The total surface area can be further increased by the coating of silica nanoparticles with ∼20 nm in diameter. During the immobilization of probe ssDNA to (3-glycidoxypropyl) trimethoxysilane functionalized surface, the nanopore resistance drops significantly by 80%, whereas the membrane capacitance increases less than 2%. After hybridization with complementary DNA, the nanopore resistance increases up to 10%. Non-complementary ssDNA has no obvious effect. The detection limit is 12.5 nM in phosphate-buffered saline (PBS) solution.
Original languageEnglish
Pages (from-to)105-112
Number of pages8
JournalSensors and Actuators, B: Chemical
Publication statusPublished - 1 Sep 2015


  • Alumina nanopore membrane
  • DNA sensor
  • Electrical impedance spectroscopy
  • Microfabrication

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry

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