Sensitivity enhancement of a dynamic mode microcantilever by stress inducer and mass inducer to detect PSA at low picogram levels

Sang Myung Lee, Kyo Seon Hwang, Hyo Jin Yoon, Dae Sung Yoon, Sang Kyung Kim, Yoon Sik Lee, Tae Song Kim

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

We report two types of signal enhancement strategy derived from the origin of mechanical response, surface stress and mass, of the dynamic mode microcantilever for the detection of PSA at low picogram scales (low femtomolar concentration). The PSA detection at extremely low concentration levels is crucial to the early detection of relapses of prostate cancer after the radical prostatectomy and the detection of breast cancer in patient's serum. There is a clear need for the ultrasensitive detection of PSA via simple and rapid diagnostic tools. From the motives, to increase the sensitivity of the microcantilever, PSA polyclonal antibody (PSA pAb) as an additional surface stress inducer and PSA polyclonal antibody-conjugated silica nanoparticles (pAb-SiNPs) as a mass inducer have been applied to the PSA-captured microcantilevers. From two types of sandwich assay, we could confirm the sensitivity enhancement effects (2∼4 times enhanced at the same concentrations) enough to detect PSA at low picogram levels (LOD of 1 pg/mL or below). Moreover, surface stress due to steric interactions between epitope-specific monoclonal antibodies was assessed to support a signal amplification strategy by stress inducer, and the reduction of signal enhancement due to stiffness increase by the mass inducer was studied to clarify the sensitivity enhancement of the microcantilever by mass inducer.

Original languageEnglish
Pages (from-to)2683-2690
Number of pages8
JournalLab on a Chip
Volume9
Issue number18
DOIs
Publication statusPublished - 2009
Externally publishedYes

ASJC Scopus subject areas

  • Bioengineering
  • Biochemistry
  • Chemistry(all)
  • Biomedical Engineering

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