Preparation of organic dye-modified calcium-aluminum layered double hydroxide powders and their cytotoxicity

Abstract

Incorporation of anions of indigo carmine dye and dodecyl sulphate to CaAl-layered double hydroxides (LDHs) has been carried out by the coprecipitation method. The effect of Ca2+/Al3+ ions ratio on the color and photostability of the composites was studied. The FE-SEM images suggested that the CaAl/Indigo and CaAl/SDS/Indigo composites formed plate-like structure with loose stacking. XRD results showed that the CaAl-LDH were mainly composed of CaAl-hydrotalcites structure. The FT-IR spectra revealed the interaction between the sulfate groups and the LDH surface, and the functional groups of each counterpart were present. The UV-Vis absorption spectra of the CaAl/Indigo and CaAl/SDS/Indigo composites exhibited intense blue color. Furthermore, the CaAl/Indigo and CaAl/SDS/Indigo composites exhibited high photo-stability under UV irradiation. Cytotoxicity was then assessed using the methyl tetrazolium test (MTT) and the cell survival rate was determined. Cytotoxicity tests showed that most CaAl/Indigo and CaAl/SDS/Indigo composites are biocompatible to the GF cells except the SDS modified CaAl-hydrotalcites structure.