Investigation of the detection of bacteria in water and food samples using bioconjugated fluorescent nanoparticles
Summary
In Sri Lanka, communicable diseases due to bacterial and viral infections are a common cause of death. However, the Weekly Epidemiological Report published by the Ministry of Health, Nutrition and Indigenous Medicine, in 2017 (Vol. 44; No:40), reports that an estimated 2.2 million people annually die due to food and water borne diarrhoea. This is mostly due to unsafe handling of food. Water sources are often contaminated with human and animal feces due to improper disposal, lack of sanitary requirements, and most of the times due to the lack of education, concern and responsibility of the public. Not only the consumers, but the food handlers, distributors and dealers should follow proper food safety protocols. If this is failed, at least there should be a proper mechanism to effectively identify such contamination in food and water sources.
This research project is focused on developing a new biosensor(s) which will respond to selected microorganisms commonly detected in contaminated food and water. A device or a protocol will be developed which is easy to be handled by the testing personnel in quality assurance laboratories, and the staff at the point of production and/or sales and distribution.
Objectives
1. To optimize the synthesis of fluorescent silica nanoparticles using various synthetic methods and various dyes. The size of the nanoparticles will be tuned to particle sizes that best suit biological applications studied in this project. The synthesized nanoparticles will be characterized to determine their particle size, shape and morphology. Also, their colloidal stability and dispersity will be investigated in solution. In addition to this, the ability to store the synthesized nanoparticles for prolonged periods will be analyzed.
2. To determine the dye-leakage and photostability of the fluorescent silica nanoparticles. Their stability under bright light is an essential parameter to be tested. The idea is to make the dyes more photostable in the silica matrix, compared to free dyes in solution.
3. To functionalize the fluorescent silica nanoparticles with various functionalities such as amine and carboxylic groups. This will enable the particles to conjugate with biological molecules.
4. To investigate the possibility of using the bioconjugated, functionalized, fluorescent silica nanoparticles in bioimaging applications to identify cancer cells.