2015/report/debugging/prototype

To determine if blue light scattering affects green fluorescence detection which would distort arsenic concentration, we analysed the light spectrum of different samples using spectruino.

We wanted to test our sample with the first prototype. For that, we removed the detector, drilled a small hole and placed the spectruino to test the blue light and the green fluorescence. We took care of the spectruino angle and spectruino height with regard the prototype.

But Spectruino didn’t detect any light spectrum!!! To solve it we tried:

Nothing happened with spectruino!!!

First, we placed the blue light at 4 cm from spectruino  and the light placed in front of spectruino (not as in the prototype, where the light is under the vial and it is deviated)

We can see one blue peak with an intensity about 180[]. That’s what we expected

We inserted free GFP sample between the blue led and the spectruino  at 4cm.

We can see two peaks, one blue peak  with an intensity about 80[] and a green peak with an intensity about 80[].

The intensity decreases when the light goes through a liquid

Secondly, we placed the blue light at 10 cm from spectruino  and the light placed in front of spectruino (not as in the prototype, where the light is under the vial and it is deviated)

We can see one blue peak  with an intensity about 90[]

That’s what we expected: The intensity decreases with the distance.

With Free GFP: We inserted free GFP sample between the blue led and the spectruino  at 10cm.

We observed only one little  blue peak with an intensity about 30[]

The green peak disappeared

  

Thirdly, we placed the blue light at 15cm from spectruino  and the light placed in front of spectruino (not as in the prototype, where the light is under the vial and it is deviated)

We placed the blue light in front of spectruino at 4cm and increased the distance until 15cm (to be sure that the problem doesn’t come from the angle).

We observe that the spectrum disappears step by step .

 

CONCLUSION:

The prototype has a length about 23 cm and the light is not in front of the spectruino but it deviates. So the spectruino is not sensitive enough to detect the blue light and the green fluorescence. We thought to use the second prototype, but its length is 12 cm, still too far away, and the light is deviated so same conclusion : spectruino cannot detect the spectrum. So we decided to create a box to test our sample

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