Detection
We used Arduino UNO with a light frequency converter to detect the light intensity of GFP, and a color detector to distinguish the color of the test paper.
Fluorescence detection
First, we set the light frequency converter(TSL235R) to measure the light intensity of GFP emitted from our CSP and Lactic acid detectors.
Secondly, we created a standard curve by using a measuring instrument in our laboratory to detect the light intensity emitted from known concentrations of CSP and Lactic acid precisely.
Finally, we compared the light intensity detected by our device with the standard curve to determine the concentration of CSP or Lactic acid in the sample.
Optical system
For the detection of the fluorescence emitted by the bacteria after it combines with the targets, a monochromatic light(485nm) was set to excite the fluorescent protein. An optical sensor(TSL235R), two lens and a longpass filter(510nm) were placed to filter the unwanted light and focus the rest onto the optical sensor to detect its fluorescence intensity.
The monochromatic light
The GFP we were using was GFPmut3. Picture A shows the excitation maxima of GFPmut3 is 501nm, and picture B shows the emission maxima is 511nm.
