What we were focusing on for the last months was factorising the process of our prototype, to be able to precisely understand which part does not work, instead of looking at the whole process not working and wondering why!
Let us analyse the light :
We know that we are exciting the sample with a know and controlled quantity of light IE. We then measure a total quantity of light I, that comes from fluorescence (IF) and scattering (IS).
With the red LED that we added underneath our vial, we can shine our sample with a know quantity of light, the light measured is only due to scattering. By subtracting IS to I, we should then obtain IF.
For the continuation of the project, this is the hypothesis we are working on, and the next experiments we are going to do are related to analysing the process of our fluorimeter. We want to analyse each component of the light and will therefore proceed to test more simple molecules in our prototype.
- FITC (a green fluorescent molecule) : Fluorescence but no scattering
- Cream : Scattering but no fluorescence
- Cream + Dextran : Fluorescence and scattering, but we know exactly how each of them behaves separately.
- E.Coli : Scattering from a biological medium
- eGFP : E.Coli constantly producing eGFP, scattering from a biological medium and fluorescence.
- And finally, our biosensor!
These series of tests will help us understand our prototype much better and to know exactly where is our problem for detecting the low levels of fluorescence that are present when our biosensor is in presence of arsenic!