The Synthesis And Biological Applications Of CNHs/CS/CdTe Nanocomposites

Due to their excellent photophysical properties, quantum dots (QDs) became the hotspot of fluorescent probes, and were increasely applied in biological labeling and imaging. Carbon nanohorns (CNHs) gained increasing attention too. Compared with carbon nanotube, CNHs show many advantages, such as high purity, high reactivity and more space for drug storage, allowing it to be a perfect carrier for targeted medicine. Therefore, the preparation of a new compositional nanomaterial, CNHs/QDs is of important significance for fluorescence labeling and targeted drug delivery. Based on our knowledge, by now, there is no report on the synthesis and application of CNHs/QDs nanocomposites published. In this study, the CNHs/QDs nanocomposites were synthesized successfully via the use of chitosan (CS) as bridge, and applied for the labeling of HeLa cells and in vivo imaging by using C.elegans as animal mode. The main contents are as follows:TGA stabilized CdTe QDs emiting different fluorescence colors were synthesized by a hydrothermal method, with good fluorescence performance.Chitosan was capped on the surface of nanohorns by glutaraldehyde with surface-deposition and cross-linking to form the nanohorns-chitosan (CNHs/CS) composites, achieving plenty of amino groups on the nanohorns surface. Meanwhile, the aggregation degree of CNHs was weaken and the water-solubility was improved due to the surface charge effect of chitosan.In the presence of activator (EDC and NHS), the CdTe QDs were conjugated with aforementioned CNHs-CS nanocomposite to form CNHs/CS/QDs nanocomposites. The optimized reaction conditions were as follows:the mixture with the volume ratio of2:3(CNHs/CS:CdTe), the pH value adjusted to7, stirred for90min under50℃. FT-IR, XRD, TEM, EDS and fluorescent spectra were used to characterize the multifunctional nanocomposites, and the results were satisfied.The CNHs/CS/QDs nanocomposites were successfully applied for the in vivo imaging of Caenorhabditis elegans. The effects of incubation time, particle concentration and fluorescent color were studied, respectively.The CNHs/CS/QDs nanocomposites were coupled with transferrin to form a probe, which was used as markers to label and image live HeLa cell. The cytotoxicity of CHNs/CS/QDs was investigated by MTT method. Experimental results indicated that the prepared nanocomposites showed low toxicity and commendable applicational prospects for targeted drug delivery.