Studying on Synthesis of Highly Luminescent Quantum Dots Based on Zinc and Their Application for Escherichia coli O157: H7 and Methicillin- Resistant Staphylococcus aureus Detection

The synthesis of highly luminescent quantum dots ZnSe/ZnS:Mn(5%)/ZnS và ZnSe:Ag(1%) in aqueous phase was studied. This synthetic method is for green chemistry. Silver and manganese are used as a dopant to increase photoluminescence quantum yields of obtained products. Mercaptopropionic acid (MPA) is used as a capping agent which is a sufficient bridge to combine the quantum dots and antibody, bacteria via protein or EDC (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride). Escherichia coli O157: H7 and methicillin-resistant Staphylococcus aureus (E. coli O157: H7 and MRSA) are leading causes of food poisoning and they are also detected via luminescent signals. The results showed that the quantum dot complex was capable of detecting bacteria at 101 CFU / ml for 15 – 30 minutes. The specificity of the reaction is 100%. Optimal antibody concentration for detection of bacteria from 10 mg to 30 mg. Rapid detection of MRSA and E. coli O157: H7 on food and clinical samples are going on further test.