Rapid and simple immunosensing system for simultaneous detection of tumor markers based on negative-dielectrophoretic manipulation of microparticles

Hyun Jung Lee, Sang Hyun Lee, Tomoyuki Yasukawa, Javier Ramon A., Fumio Mizutani, Kosuke Ino, Hitoshi Shiku, Tomokazu Matsue

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

We report here a rapid, simple, and simultaneous immunosensing method for two tumor markers, alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA), by applying the negative-dielectrophoretic (n-DEP) manipulation of microparticles. Microparticles modified with different antibodies rapidly accumulated to designated areas of poly(dimethylsiloxane) (PDMS) fluidic channels modified with different antibodies within 1 min by n-DEP upon the application of AC voltage. The presence of specific antigens, AFP or CEA, permitted the irreversible capture of microparticles via the formation of immuno-complexes between the PDMS surface and the microparticles. Uncaptured microparticles redispersed after switching off the AC voltage. The fluorescent intensity from the irreversibly captured microparticles allowed us to determine the concentration of AFP and CEA in the sample. Neither the unreacted analytes nor the microparticles required separation steps, since we detected the fluorescent signals only from the microparticles captured on the PDMS surface. The detectable concentration range shifted to lower values when the amount of the antibody on the PDMS surface increased. The range for both AFP and CEA assays was 0.1-100 ng/mL, which was sufficient to cover the concentration required for the medical diagnoses. We simultaneously detected the concentrations of AFP and CEA by using a device, with two channels modified for different antibodies. Since n-DEP was used for the rapid manipulation of the microparticles toward the PDMS surface, the time required for the assay was substantially short; 1 min for forcing and 5 min for redispersion of the microparticles and sensing.

Original languageEnglish
Pages (from-to)657-663
Number of pages7
JournalTalanta
Volume81
Issue number1-2
DOIs
Publication statusPublished - 2010 Apr 15

Keywords

  • Microparticles
  • Multianalyte
  • Negative-dielectrophoresis
  • One-step immunosensing
  • Redispersion

ASJC Scopus subject areas

  • Analytical Chemistry

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