Label-Free Detection of DNA-Binding Proteins Based on Microfluidic Solid-State Molecular Beacon Sensor

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• 作者：Jun Wang ; Daisuke Onoshima ; Michihiko Aki ; Yukihiro Okamoto ; Noritada Kaji ; Manabu Tokeshi ; Yoshinobu Baba
• 刊名：Analytical Chemistry
• 出版年：2011
• 出版时间：May 1, 2011
• 年：2011
• 卷：83
• 期：9
• 页码：3528-3532
• 全文大小：756K
• 年卷期：v.83,no.9(May 1, 2011)
• ISSN：1520-6882

文摘

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.