Photon induced quantum yield regeneration of cap-exchanged CdSe/CdS quantum rods for ratiometric biosensing and cellular imaging

Nanoscale. 2020 Apr 28;12(16):8647-8655. doi: 10.1039/c9nr08060k. Epub 2020 Mar 9.

Abstract

Full water-dispersion of commercial hydrophobic CdSe/CdS core/shell quantum rods (QRs) was achieved by cap-exchange using a dihydrolipoic acid zwitterion ligand at a low ligand:QR molar ratio (LQMR) of 1000. However, this process almost completely quenched the QR fluorescence, greatly limiting its potential in downstream fluorescence based applications. Fortunately, we found that the QR fluorescence could be recovered by exposure to near ultra-violet to blue light radiation (e.g. 300-450 nm). These "reborn" QRs were found to be compact, bright, and stable, and were resistant to non-specific adsorption, which make them powerful fluorescent probes in broad biomedical applications. We demonstrated their potential in two model applications: first, the QRs were conjugated with His8-tagged small antibody mimetic proteins (also known as Affimers) for the sensitive detection of target proteins via a Förster resonance energy transfer (FRET) readout strategy and second, the QR surface was functionalized with biotins for targeted imaging of cancer cells.

MeSH terms

  • Biosensing Techniques / methods*
  • Biotin / chemistry
  • Cadmium Compounds / chemistry*
  • Cell Line, Tumor
  • Fluorescence Resonance Energy Transfer
  • Humans
  • Ligands
  • Light
  • Microscopy, Fluorescence / methods*
  • Photons
  • Quantum Dots / chemistry*
  • Selenium Compounds / chemistry*
  • Small Ubiquitin-Related Modifier Proteins / chemistry
  • Sulfides / chemistry*
  • Thioctic Acid / analogs & derivatives
  • Thioctic Acid / chemistry
  • Ultraviolet Rays

Substances

  • Cadmium Compounds
  • Ligands
  • Selenium Compounds
  • Small Ubiquitin-Related Modifier Proteins
  • Sulfides
  • cadmium sulfide
  • Biotin
  • Thioctic Acid
  • dihydrolipoic acid
  • cadmium selenide