Quantum dot FRET biosensors that respond to pH, to proteolytic or nucleolytic cleavage, to DNA synthesis, or to a multiplexing combination

J Am Chem Soc. 2008 Apr 30;130(17):5720-5. doi: 10.1021/ja710870e. Epub 2008 Apr 5.


Fluorescent acceptors have been immobilized on nanoparticulate quantum dots (QDs), which serve in turn as their FRET donors. The broad excitation and narrow emission bands of QDs mark them as having excellent potential as donors for FRET and, in principle, differently colored QDs could be excited simultaneously. The present work describes the preparation and operation of FRET-based QD bioprobes individually able to detect the actions of protease, deoxyribonuclease, DNA polymerase, or changes in pH. In addition, two such QD-mounted biosensors were excited at a single wavelength, and shown to operate simultaneously and independently of each other in the same sample solution, allowing multiplex detection of the action of a protease, trypsin, in the presence of deoxyribonuclease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosensing Techniques / methods*
  • DNA* / analysis
  • DNA* / biosynthesis
  • DNA-Directed DNA Polymerase / analysis
  • DNA-Directed DNA Polymerase / metabolism
  • Deoxyribonucleases / analysis
  • Deoxyribonucleases / metabolism
  • Fluorescence Resonance Energy Transfer / methods*
  • Hydrogen-Ion Concentration
  • Peptide Hydrolases* / analysis
  • Peptide Hydrolases* / metabolism
  • Quantum Dots*
  • Solutions / chemistry
  • Trypsin / analysis
  • Trypsin / metabolism


  • Solutions
  • DNA
  • DNA-Directed DNA Polymerase
  • Deoxyribonucleases
  • Peptide Hydrolases
  • Trypsin