The gold nanoclusters (Au-NCs) have emerged for delivery of various payloads such as small molecular drug and big molecular proteins due to their low immunogenicity, quick clearance and good biocompatibility. Even though they have shown great prospective in biomedical area, there are also some security problems which should be investigated further more. BRCAA1 mAb Au-NCs is a probe for gastric cancer diagnosis prepared by conjugating BRCAA1 monoclonal antibody with fluorescent Au-NCs. In this research, the renal excretion and effect on glomerulus filtration of BRCAA1 mAb AuNCs in rats were investigated. The result indicated that BRCAA1 mAb Au-NCs could be eliminated through the glomerulus filtration as early as 2 hr after the administration following the excretion of other proteins in the plasma such as immunoglobulin. Electron microscope image and pathological analysis of kidney showed that BRCAA1 mAb Au-NCs induced some structural injury such as capillaries endotheliocyte damage, pycnosis, karyorrhexis and hyalomitome acidophilia enhancement. Biochemical indexes including ALT, AST, BUN, TBIL, CK and CREA are abnormal in the period of 2 to 48 hr after the administration. The results of Western blotting and immunohistochemisty show the downregulation of three key proteins (ZO-1, Nephrin and Podocin) indicating the influence of BRCAA1 mAb Au-NCs on the foot processes of glomerular epithelial cells and shallow intercellular junctions or slit diaphragms.

Ricin has been considered as a potential agent of biological warfare or terrorist attack. This work is aimed to develop and evaluate a rapid test strip for the assay of ricin in environmental and biological samples. Two specific antibodies were used respectively as the capture antibody (Mab 4C13) coated on a nitrocellulose membrane and the tracing antibody (MAb 3D74) labeled with colloidal gold. The immunochromatography strips were tested to detect ricin in porridge, salted vegetable, water and other drinks. The detection could be finished within fifteen minutes and its sensitivity was at 10 ng/ml of ricin in water. When no ricin control samples were tested in parallel, some kind of drinks, such as Sprite and Coca cola showed false positive bands even without toxin pollution, indicating the negative control is essential to avoid possible false positive results. The strips could give positive signals after loading human serum sample mixed with 25 ng ml^-1 of ricin in vitro. When rats were intramuscularly treated with 100 ug kg^-1 of ricin, the residual ricin in the serum samples could be successfully detected by the strips even at 24 h after intoxication. The immunochromatography test strip is a useful tool to check the possible pollution of ricin in enviromental samples such as drink and food, and even to detect the residual toxin in human serum before victim developing intoxication symptoms.