Label-free detection of DNA-binding proteins based on microfluidic solid-state molecular beacon sensor

Jun Wang, Daisuke Onoshima, Michihiko Aki, Yukihiro Okamoto, Noritada Kaji, Manabu Tokeshi, Yoshinobu Baba

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

A solid-state molecular beacon using a gold support as a fluorescence quencher is combined with a polydimethylsiloxane (PDMS) microfluidic channel to construct an optical sensor for detecting single-stranded DNA binding protein (SSBP) and histone protein. The single-stranded DNA-Cy3 probe or double-stranded DNA-Cy3 probe immobilized on the gold surface is prepared for the detection of SSBP or histone, respectively. Due to the different quenching ability of gold to the immobilized single-stranded DNA-Cy3 probe and the immobilized double-stranded DNA-Cy3 probe, low fluorescence intensity of the attached single-stranded DNA-Cy3 is obtained in SSBP detection, whereas high fluorescence intensity of the attached double-stranded DNA-Cy3 is obtained in histone detection. The amounts of SSBP in sample solutions are determined from the degree of fluorescence recovery of the immobilized single-stranded DNA-Cy3 probe, whereas that of histone in sample solutions is determined from the degree of fluorescence quenching of the immobilized double-stranded DNA-Cy3 probe. Using this approach, label-free detection of target proteins at nanomolar concentrations is achieved in a convenient, general, continuous flow format. Our approach has high potential for the highly sensitive label-free detection of various proteins based on binding-induced conformation changes of immobilized DNA probes.

Original languageEnglish
Pages (from-to)3528-3532
Number of pages5
JournalAnalytical chemistry
Volume83
Issue number9
DOIs
Publication statusPublished - May 1 2011
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry

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