|
Quantum dots (also known as semiconductor nanocrystals) is an emerging nano-materials, due to having a size adjustable fluorescent emission, narrow and symmetric emission spectrum, a broad and continuous absorption spectra, an excellent light stability and other advantages and in wide range of applications in the biomedical field . With the quantum dots in biological applications in the field of expanding and deepening , people are increasingly concerned about the biological safety of this material . This article from the particle size and concentration of CdTe quantum dots , stabilizer type , exposure time , and quantum dots surface modification , the systematic investigation of its toxicity . The main work is as follows : First, we take advantage of the traditional water - phase synthesis method different emission wavelength of CdTe quantum dots , using the WST-1 reagent method to study the toxicity of CdTe quantum dots on human cervical cancer cells (SiHa) . The study found : several common mercapto stabilizers , glutathione (GSH) contribute to the reduction in the toxicity of quantum dots ; quantum dot toxicity obvious size effect , time and dose effects ; particle size of the quantum dots Vietnam is small , the exposure time is longer , the greater the concentration , the greater the toxic to cells . We speculate that the surface state of the quantum dot toxicity . Try to be modified in order to improve the surface state of quantum dots , the study found that: a biological macromolecule , bovine serum albumin ( BSA ) , denatured bovine serum albumin ( DBSA ) QDs , there was no difference of the quantum dots of its toxicity and the bare ; via mercapto- polyethylene glycol modified (Thiol-PEG) , the toxicity of quantum dots is slightly reduced; CdS and ZnS shell coated the surface of the CdTe quantum dots , quantum dots toxicity is significantly reduced , the CdTe / CdS / ZnS and SiHa cells were co-cultured 48h, cell viability was still as high as 89.3% , a total of 24 hours of incubation of the cells has almost no effect . This may be due The ZnS shell passivates the surface of the CdTe quantum dots , changing the surface state of the CdTe quantum dots , thereby reducing the cytotoxicity .
|