Aqueous CdTe colloidal Quantum Dots for Bio-imaging of Artemia

Abstract Aqueous Cadmium Telluride (CdTe) colloidal quantum dots was synthesized using 3-mercaptoproponic acid (3-MPA) as a capping agent. CdTe QDs with band gap of 2.26 eV exhibit absorption edge and florescence emission at 502 nm and 569 nm respectively. The shoulder peak appearance in florescence emission owing to state filling effect. The cubic zinc-blend crystal structure of CdTe QDs are confirmed from XRD pattern with crystallite size ∼ 2.12 nm. The morphological analysis carried out through HRTEM show spherical shaped particles with the average particles size of 3-MPA capped CdTe QDs is 3.3 nm. The elemental compositional and capping effect of the 3-MPA caped CdTe QDs are characterized via EDS, FTIR spectrum and Raman analysis. The bioimaging of Artemia using CdTe QDs is accomplished by way of dipping the Artemia animal into greenish-yellow colored (λemission 569) CdTe QDs aqueous solution. The fluorescent images showed clear morphology features of dead juvenile Artemia without affecting their internal and external structure. The linking of CdTe QDs to calcium localized in different cytoplasmic compartments of juvenile Artemia spp through MPA ligand lead to obtain the bright images. This study confirm that water soluble colloidal CdTe QDs well suitable for external morphological observation in a lower invertebrate like Artemia, Daphnia and jellyfishes.