Team:Linkoping Sweden/Detector

The detector

To detect the FRET effect we will need an apparatus that can excite FITC and at the same time detect when FRET occurs between FITC and RFP. Our aim is to build a very small fixed wavelength spectrophotometer with good performance to a relatively low cost. The excitation energy will come from a LED source and only wavelengths between 480-500 nm will pass a short band pass optical filter with a peak maximum at 488 nm. This overlaps very precisely with the excitation peak for FITC. This light hits the sample cuvette and makes FRET occur between the complexes. The now red-shifted photons emitted from RFP will pass one of two filters, one which only allows red light through, and one which allows red and green light through. The photons then hit one of two calibrated Si-photodiode sensors depending on which filter the photons went through. This will give outputs that can be read by a microcontroller, in our case an Arduino. If ara h 1 protein is available, the antibodies will bind the protein instead of the RFP-complex.

The protein complex shift leads to the sensor that detects both red and green light will have a bigger output than the one that only detects red light. The Arduino will then process the outputs and if the sample contains peanut protein a red LED lamp on the top of the detector will shine. If the sample does not contain any peanut protein a green LED will indicate this instead.