Solubilization of quantum dots with a recombinant peptide from escherichia coli

The passivation of quantum dots (QD) surface with recombinant peptide produced in Escherichia coli were studied. Optical absorptions spectroscopy was used to determine the number of peptides bound to the QD at the end of the exchange reaction. Aqueous size-exclusion high-pressure liquid chromatography (SE-HPLC) and scanning tunneling electron microscopy (STEM) were adopted for the separation and characterization of different sized of CdSe-protein conjugates. Hydrodynamic radii were determined from the measured diffusion constants and by comparing the FCS decay curves with that of 26-nm fluorescent beads. Molecular evolution strategies to randomize peptides could be adopted to select high-affinity binders to the QD surface. here was also a possibility of creating multi-functional QDs by mixing peptide sequences in certain molar ratios in a single step for in vitro and in-vivo studies.