title: Robust silica-coated quantum dot-molecular beacon for highly sensitive DNA detection.
abstract: We synthesized and characterized small yet highly robust silica-coated quantum dots (QDs) and then used them to develop highly sensitive molecular beacon (MB) for DNA detection. As compared to the previously reported methods, our silica coating approach enabled simple and rapid synthesis of silica-coated QDs in large quantities and high concentrations with a well-controlled silica layer. The QDs such made were stable and had a high quantum yield in a wide range of pH values (1-14) and high salt concentrations (up to 2 M). They were less than 10 nm in diameter, much smaller than current silica-coated QDs, thus allowing for efficient energy transfer. The MB sensor based on these silica-coated QDs was capable of rapidly detecting the target DNA at 0.1 nM concentration within 15 min. It could also differentiate the target DNA from the single base mismatched DNA. The QD-MB developed in this work can be used for highly sensitive and selective detection of DNA and other biomolecules in homogeneous solution and inside a cell, as well as in harsh environment.
authors: Biomedical Engineering Department, University of Michigan 1101 Beal Avenue Ann Arbor, MI 48109 USA; Department of Biological Engineering, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.
authors: Chung-Shieh
authors: CS
authors: Wu
authors: Biomedical Engineering Department, University of Michigan 1101 Beal Avenue Ann Arbor, MI 48109 USA.
authors: Maung Kyaw Khaing
authors: MK
authors: Oo
authors: Department of Biological Engineering, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.
authors: Jay M
authors: JM
authors: Cupps
authors: Biomedical Engineering Department, University of Michigan 1101 Beal Avenue Ann Arbor, MI 48109 USA.
authors: Xudong
authors: X
authors: Fan
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification*; D045663:Quantum Dots / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D012822:Silicon Dioxide; D004247:DNA