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Updated: Mar 14, 2026
Synthesis of Wavelength-shifting DNA Hybridization Probes by Using Photostable Cyanine Dyes
Published on: July 6, 2016
Synthesis and characterization of DNA-quantum dot conjugates for the fluorescence ratiometric detection of unlabelled
Leah Elizabeth Page1, Xi Zhang, Christina Marie Tyrakowski
1Department of Chemistry, the University of Illinois at Chicago, 845 W. Taylor St., Chicago, Il 60607-2405, USA. sneep@uic.edu.
Abstract:
A quantum dot-based ratiometrically responsive fluorescent sensor for unlabeled single-stranded DNA (ssDNA) is reported. Several technical issues concerning the development of high yield ssDNA-QD conjugation chemistry were addressed. The DNA sensor was synthesized by conjugating methacrylic phosphoramidite-functional oligonucleotides to water-soluble cadmium zinc sulfide core/zinc sulfide shell quantum dots (CdZnS/ZnS QDs). Duplex DNA was formed when the QD-bound ssDNA was incubated with its complement. Next, titration with PicoGreen resulted in FRET energy transfer from the dot to the dsDNA intercalating dye. The resulting ratio of the dye to QD integrated emissions is a calibratable metric for label-free DNA detection with a LOD of 3.8 nmol.
