Zwitterion Modified ZnO Quantum Dots And GO: Fabrication And Properties In Bio-medium

Zinc oxide quantum dots have a great application prospect as biological fluorescence labeling because of their prominent fluorescent properties and non-toxicity.The drug-loading and release behavior of graphene oxide have also attracted attention in recent years.But a common requirement for them is that they must be dimensionally stable in biological medium.Zwitterionic modification is an important way to improve the stability of the nanoparticlesIn this paper,zwitterion modified ZnO quantum dots(ZnO-ZWS)were prepared by the reaction of zwitterion based silicane with zinc oxide.The particle size was about 3-4 nm,the hydration particle size was about 8 nm,and there was no obvious growth in size when exposed to serum solution.Results showed that the zwitterion coated Zn O QDs can be stable both under harsh salt condition and in serum for at least 30 days while maintaining part of its fluorescence intensity.Similarly,GO was modified by zwitterion.Compared with the bare GO,the stability of GO-SB in serum was significantly improved.After loading of DOX,the differences between stability of DOX@GO-SB and stability of DOX@GO were extremely obvious in water or bio-media.In addition,the cytotoxicity and endocytosis was assessed,it was found that GO-SB itself did not show significant cytotoxicity.Furthermore,the influence of GO-SB on the growth of living body and its metabolism in vivo were investigated using zebrafish as a model.The results showed that zebrafish exposed to GO-SB had a survival rate of 85.4% and a teratogenic rate of 0%,comparable to the control group.The green fluorescence was appeared over time,and it was disappeared after it was incubated with water.It was confirmed that there's no significant effect to animals' growth and development as well as that GO-SB can be excreted via metabolic effects.The study provides a useful reference for the preparation of nanomaterials with good stability in biological medium.