High-speed detection of DNA translocation in nanopipettes

Research output: Contribution to journalArticle


  • Raquel L. Fraccari
  • Pietro Ciccarella
  • Azadeh Bahrami
  • Marco Carminati
  • Giorgio Ferrari

Colleges, School and Institutes

External organisations

  • Imperial College London
  • 3 Politecnico di Milano Milano, Italy.
  • Informazione e Bioingegneria
  • Dipartimento di Ingegneria Dell'Informazione, Elettronica e Telecomunicazioni, University of Rome la Sapienza
  • Politecnico di Milano


We present a high-speed electrical detection scheme based on a custom-designed CMOS amplifier which allows the analysis of DNA translocation in glass nanopipettes on a microsecond timescale. Translocation of different DNA lengths in KCl electrolyte provides a scaling factor of the DNA translocation time equal to p = 1.22, which is different from values observed previously with nanopipettes in LiCl electrolyte or with nanopores. Based on a theoretical model involving electrophoresis, hydrodynamics and surface friction, we show that the experimentally observed range of p-values may be the result of, or at least be affected by DNA adsorption and friction between the DNA and the substrate surface.


Original languageEnglish
Pages (from-to)7604-7611
Issue number14
Publication statusPublished - 11 Mar 2016