Redox heme-proteins mediated fluorescence of CdSe/ZnS quantum dots

J Photochem Photobiol B. 2014 Apr 5:133:65-72. doi: 10.1016/j.jphotobiol.2014.02.017. Epub 2014 Mar 19.

Abstract

The redox properties of cytochrome c (Cyt c), hemoglobin (Hb) and myoglobin (Mb) were studied based on electrostatic interactions between Thioglycolic acid (TGA) capped CdSe/ZnS quantum dots (QDs) and proteins. Results indicated that only Cyt c quenched the fluorescence of the QDs at pH>8.0. Under the optimized conditions, a significant fluorescence recovery of the QDs' system was observed when the reduced form of Cyt c incubated with TGA capped QDs, however, the reduced state of Hb and Mb resulted in a more fluorescence quenching on the same size of QDs. Interestingly, the fluorescence changes of QDs-proteins could be switched by modulating the redox potentials of proteins-attached QDs. Moreover, only the oxidized Cyt c form was reduced by the generated O2(-) that significantly enhanced the fluorescence of the QDs' system, which was also demonstrated by fluorescence imaging in HeLa cells.

Keywords: Electrostatic interactions; Fluorescence imaging; Quantum dots; Redox proteins; Spectroelectrochemistry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cadmium Compounds / chemistry
  • Cytochromes c / chemistry*
  • Cytochromes c / metabolism
  • HeLa Cells
  • Hemoglobins / chemistry*
  • Hemoglobins / metabolism
  • Humans
  • Microscopy, Confocal
  • Myoglobin / chemistry*
  • Myoglobin / metabolism
  • Oxidation-Reduction
  • Quantum Dots / chemistry*
  • Selenium Compounds / chemistry
  • Spectrometry, Fluorescence
  • Sulfides / chemistry
  • Thioglycolates / chemistry
  • Zinc Compounds / chemistry

Substances

  • Cadmium Compounds
  • Hemoglobins
  • Myoglobin
  • Selenium Compounds
  • Sulfides
  • Thioglycolates
  • Zinc Compounds
  • 2-mercaptoacetate
  • Cytochromes c
  • cadmium selenide
  • zinc sulfide