The Synthesis Of QDs Cadmium Sulfide Water Soluble And The Acute Toxicity Of QDs Zinc Sulfide Powder In Healthy Adult Mice

Quantum Dots (Quantum dots, QDs) is nano-materials of quasi-zero-dimension, which three-dimension's size is below 100nm,and its physical acts (such as optical, electrical properties) similar as the Atomic, also known as "artificial atoms". It is the minimal number of atoms or molecules composed of atoms or clusters. The QDs have the surface effect, the quantum size effect, the dielectric confinement effect , the macro-quantum tunnel and the other special light and electrical effects, which have extremely broad prospects for application in the nonlinear optical, catalytic, magnetic media, medicine and functional materials, has a profound impact in biological, medical development and related areas of basic research.Using quantum dots to the biological area is very active in the forefront of topics, quantum dots applied in biological and medical fields are in four main areas:1 .The living cells fluorescent optical imaging and the organizations;2.The tracer of tumor cells and its diagnostic imaging;3.The live animal imaging;4.The imaging of Hormones and other biological factors.The most promising applications of fluorescent quantum dot is use as a fluorescent marker in the biological system, so understanding its toxicity to meet the biological safety standards is very essential. This paper to fluorescent quantum dots (QDs) as our study, to Kunming mice as experimental animals, using of oral acute toxicity test, the indicators includes clinical observation of Kunming mice before and after gavage, weight gain, blood testing, liver Index, pathological changes in liver and other ,which uses to the study of mice liver and spleen's toxicity by QDs ,and provides a scientific basis to the comprehensive evaluation of the ecological mammals toxicological effects by QDs. The results show below that: 1. According the standards of compounds' acute oral toxicity, we adopted in the scope of low toxicity to the KM mice's oral acute toxicity test. the ZnS quantum dots' animal acute toxicity is determined;2. The mice's observation showed that in the initial exposured time, the digestive system of the animals had injuried seriously by ZnS quantum dots ,it also could lead to loss of appetite, dispirited and move slowly .If the toxin can not be excreted to vitro in a short period of time, the tested mice will be dead. According to the blood testing and liver slices results, confirmed that in the early exposured time, liver damage occured more serious, and as the dose increases, the degree of liver damage animals will also increase.3. Control of toxic compounds grading standards, we can know that the ZnS quantum dots' toxicity is low-toxicity, with the highest dose of 5000 mg / kg body weight as an example, one death occurred only after the poisoning,which far belows half to death. For the dose usually used as biological markers of the quantum dots do not need high dose, the Zn and S are important chemical elements for the body, and the special nature of the semiconductor elements, ZnS is still a more promised and relatively safe choice in the synthesised quantum dots.4. Solution of the quantum dots visible shows yellow liquid under visible, the synthesized CdS was detected its fluorescent intensity with fluorescence spectrophotometer, and in 395 nm it had a strong emission peak, so its fluorescence intensity at the most, and was similar with records in the anastomosis.The conclusions of this study are below:1. Synthesis of water-soluble quantum dots CdS is feasible.2. The biological toxicity of ZnS quantum dots is low-toxicity, so ZnS as a biological marker is relatively safe.