Biomolecule-assisted synthesis of 3D structure gold nanocrystals in the presence of cystamine dihydrochloride or cysteamine

A facile cystamine-assisted route was designed for the selectively controlled synthesis of 1D and novel, interesting 3D gold litchi-like nanostructures. By controlling reaction conditions such as the molar ratio between HAuCl(4) and cystamine dihydrochloride and the reaction time, the synthesis of various 3D architectural structures and 1D structure in large quantities can be controlled. The formation mechanism for the gold litchi-like assemblies with well-arranged nanorods was also discussed. In addition, as the control test, featheriness gold structures were obtained through using cysteamine as the assisted agent. On the basis of the results from SEM studies and our analysis, we speculate that the different morphologies obtained by cystamine dihydrochloride and cysteamine due to the Au-S interaction. These differences in hydrogen storage capacity are likely due to the size and density of space/pores as well as the morphology of different nanostructures. This facile, environmentally benign, and - solution-phase biomolecule-assisted method can be potentially extended to the preparation of other metal nanostructures

Quantum dots-amplified electrochemical cytochrome P450 phenotype sensor for tamoxifen, a breast cancer drug

Philosophiae Doctor - PhDBreast cancer is regarded as the most common cancer in South Africa and its rate of occurrence is increasing. About one in every 31 South African women are at the risk of developing breast cancer and early diagnosis and treatment guarantee 90% survival rate. Tamoxifen is the drugs of choice for the treatment of all stages of breast cancer. The drug binds with estrogen receptor (ER) to minimize the transcription of estrogen dependent genes. However, nearly 50% of ER-positive breast cancer patients either become resistant or fail to respond to tamoxifen resulting in a serious clinical challenge in breast cancer management. The Grand Health Challenges of South Africa includes the development of cost effective diagnostic systems suitable for early detection of diseases and drug resistivity for timely invention and better patient management