Chitosan capped CuInS2 and CuInS2/ZnS by wet stirred media milling: in vitro verification of their potential bio-imaging applications

Abstract

In this work, the mechanochemically synthesized CuInS2 and CuInS2/ZnS samples were capped with chitosan by wet stirred media milling to obtain nanosuspensions suitable for testing of their bio-imaging properties. The stability of the prepared nanosuspensions was studied using a particle size-distribution and zeta potential measurements and the results were compared. The nanosuspension of CuInS2/ZnS was stable only for 1 week, on the other hand, CuInS2 was stable for 37 weeks. Fourier-transform infrared spectroscopy was used for the determination of possible interaction between the chitosan and the inorganic entities. The optical properties were also studied using UV–Vis and PL spectroscopies. The dissolution of copper and zinc ions in a physiological solution from CuInS2 and CuInS2/ZnS samples was also investigated. The potential bio-imaging applications were verified in vitro on four cancer cell lines with no toxicity risk in a case of CuInS2 sample. The cells were more visible in comparison with non-treated ones under the fluorescence microscope. They stayed in the cytoplasm and surrounded the nucleus. Granularity and metabolic activity of the cells were strongly influenced. On the other hand, CuInS2/ZnS nanocrystals affected cell metabolism and survival and they seem not suitable for bio-imaging applications particularly in high concentrations.