Novel quantum dots comprise type-N, type-A, type-O and SiO2. Type-N is composed of 20nm SiO2 and fluorescein dissolved in ethanol. Type-A is composed of 20nm SiO2 and fluorescein dissolved in ethanol, after 12h adding 3-aminopropyltriethoxysilane to produce group -NH2 surrounding outer surface of SiO2. Type-O is composed of tetraethyl orthosilicate (TEOS), fluorescein and ethanol under sol-gel reaction for 12h therefore producing nanoparticle of SiO2 encapsulated fluorescein. In order to apply these novel quantum dots as tracers for the application in the field of biomedical engineering, we interested in the toxicity of these nano particles. In this study, we investigated that type-N had the highest tocixity for A10 (smooth muscle cells) and subsequently SiO2 coated with gold was the least cytotoxic one. In any case, the cytotoxicity strength is type-N > type-A > SiO2 > type-O >nano gold> SiO2 coated with gold. In conclusion, we suggested gold coated on the surface of SiO2 could diminish the cytotoxic of smooth muscle cells, moreover, among the preparation of sol-gel reaction about type-O, acceding tetraethyl orthosilicate (TEOS) may encapsulate fluorescein completely.
