The modification of quantum dot probes used for the targeted imaging of his-tagged fusion proteins.

In molecular biology and protein detection the immobilized metal ion clusters using a NTA-chelator is a powerful technique in identification and isolation of histidine-tagged fusion proteins. The Oligo-histidine tag should serve as a high affinity binding sequence for the purification of any fusion protein via metal chelating adsorbents. We described the preparation and characterization of bioinorganic conjugates made with highly luminescent semiconductor CdTe-CdS core-shell quantum dots (QDs) for biological labeling. A biocompatible surface-functionalized nanoparticle was designed to sense histidine-tagged fusion proteins. This study demonstrates the synthesis of Ni-NTA conjugated QD nanoparticles and the successful application of these nanoparticles to the detection of histidine-tagged fusion proteins. It is believed that this approach will provide a more convenient methodology for the intracellular localization of histidine-tagged protein, as compared with current methods. These Ni-NTA-QD clusters were shown to target the 6x histidine region of tagged proteins specially.