Ultrasensitive and label-free detection of pathogenic avian influenza DNA by using CMOS impedimetric sensors

Wei An Lai, Chih Heng Lin, Yuh-Shyong Yang, Michael S.C. Lu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

38 Scopus citations


This work presents miniaturized CMOS (complementary metal oxide semiconductor) sensors for non-faradic impedimetric detection of AIV (avian influenza virus) oligonucleotides. The signal-to-noise ratio is significantly improved by monolithic sensor integration to reduce the effect of parasitic capacitances. The use of sub-μm interdigitated microelectrodes is also beneficial for promoting the signal coupling efficiency. Capacitance changes associated with surface modification, functionalization, and DNA hybridization were extracted from the measured frequency responses based on an equivalent-circuit model. Hybridization of the AIV H5 capture and target DNA probes produced a capacitance reduction of -13.2 ± 2.1% for target DNA concentrations from 1. fM to 10. fM, while a capacitance increase was observed when H5 target DNA was replaced with non-complementary H7 target DNA. With the demonstrated superior sensing capabilities, this miniaturized CMOS sensing platform shows great potential for label-free point-of-care biosensing applications.

Original languageEnglish
Pages (from-to)456-460
Number of pages5
JournalBiosensors and Bioelectronics
Issue number1
StatePublished - 15 May 2012


  • Avian influenza virus
  • CMOS
  • Integrated circuit
  • Interdigitated microelectrode

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