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.