A microfluidic-based electrochemical biochip for label-free diffusion-restricted DNA hybridization analysis

Hadar Ben-Yoav, Peter H. Dykstra, William E. Bentley, Reza Ghodssi

Research output: Contribution to journalArticlepeer-review

43 Scopus citations

Abstract

DNA hybridization detection in microfluidic devices can reduce sample volumes, processing times, and can be integrated with other measurements. However, as device footprints decrease and their complexity increase, the signal-to-noise ratio in these systems also decreases and the sensitivity is thereby compromised. Device miniaturization produces distinct properties and phenomena with greater influence at the micro-scale than at the macro-scale. Here, a diffusion-restriction model was applied to a miniaturized biochip nanovolume reactor to accurately characterize DNA hybridization events that contribute to shifts in both charge transfer resistance and diffusional resistance. These effects are shown to play a significant role in electrochemical impedance spectroscopy (EIS) analyses at these length scales. Our highly functional microfluidic biosensor enables the detection of ssDNA targets selectively, with a calculated detection limit of 3.8. nM, and cross-reactivity of 13% following 20. min incubation with the target. This new biosensing approach can be further modeled and tested elucidating diffusion behavior in miniaturized devices and improving the performance of biosensors.

Original languageEnglish
Pages (from-to)114-120
Number of pages7
JournalBiosensors and Bioelectronics
Volume38
Issue number1
DOIs
StatePublished - 1 Oct 2012
Externally publishedYes

Keywords

  • Biochip
  • DNA hybridization biosensor
  • Electrochemical impedance spectroscopy
  • Label-free detection
  • Microfluidics
  • Restricted diffusion

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry

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