Novel electrical detection of label-free disease marker proteins using piezoresistive self-sensing micro-cantilevers

Kyung Wook Wee, Ghi Yuun Kang, Jaebum Park, Ji Yoon Kang, Dae Sung Yoon, Jung Ho Park, Tae Song Kim

Research output: Contribution to journalArticle

221 Citations (Scopus)

Abstract

We report an electro-mechanical biosensor for electrical detection of proteins with disease markers using self-sensing piezoresistive micro-cantilevers. Electrical detection, via surface stress changes, of antigen-antibody (Ag-Ab) specific binding was accomplished through a direct nano-mechanical response of micro-fabricated self-sensing micro-cantilevers. A piezoresistive sensor measures the film resistance variation with respect to surface stress caused by biomolecules specific binding. When specific binding occurred on a functionalized Au surface, surface stress was induced throughout the cantilever, resulting in cantilever bending and resistance change of the piezoresistive layer. The cantilever biosensors were used for the detection of prostate specific antigen (PSA) and C-reactive proteins (CRP), which are a specific marker of prostate cancer and cardiac disease. From the above experiment, it was revealed that the sensor output voltage was proportional to the injected antigen concentration (without antigen, 10 ng/ml, 100 ng/ml, 1 μg/ml). PSA and CRP antibodies were found to be very specific for their antigens, respectively. This indicated that the self-sensing micro-cantilever approach is beneficial for detecting disease markers, and our piezoresistive micro-cantilever sensor system is applicable to miniaturized biosensor systems.

Original languageEnglish
Pages (from-to)1932-1938
Number of pages7
JournalBiosensors and Bioelectronics
Volume20
Issue number10 SPEC. ISS.
DOIs
Publication statusPublished - 2005 Apr 15

Keywords

  • Antibody
  • Antigen
  • Micro-cantilever
  • Nano-mechanics
  • Piezoresistivity

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry

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