I just got my sensor working! This is the key element of the LAMP diagnostic device, and something I don't think has ever been done before. Digital multi-channel fluorescence spectroscopy with a sub $2 chip, The other half of the device, the precision temperature regulation system, is something I already have working in my PCR Machine. So, the main components of the diagnostic device are past the proof-of-principal phase!

A big thanks goes to Christoph on the Hacker Channel, who helped get my I2C device working!

I'm using the VEML6040 RGBW color sensor, and a 405NM UV led to excite fluorescein, which had the same excitation and emission profile as Calcein, the dye I plan to use for the detector device.

The SMD part is a tiny 4-pin device, which I have soldered onto copper wire, and then onto header pins.

The illumination is set at a 90 degree offset to the sample.

I use the UV to excite sample of water and 50 micromolar Fluorescein.

The fluorescein solution generates a bright green fluorescence, and the water none. Then if was time to record data, over the serial port from the Arduino:

UV led H2O:
red channel	8291
green channel	11501
blue channel	46281
white channel	65535

UV led 50um Fluorescein:
red channel	11543
green channel	17613
blue channel	44271
white channel	65535

Theres a good increase in the Green channel, over 50%. Whats great, is that by using a RGB led, we can do positive and negative controls!

UV led 50um Fluorescein, lid open
red channel	43481
green channel	41390
blue channel	35962
white channel	65535

UV led 50um Fluorescein, LED off
red channel	311
green channel	271
blue channel	111
white channel	1208

If the UV led breaks, the blue channel drop by 99%, and if the lid is opened, the red channel goes up 500%. What that means is we can detect if there is a problem with the UV led, or if someone opens the device while the reaction is going on, both of which are vital for a diagnostic device!

Thing are going really well! I think with this key step done, I'll have the device completed in time for the 2015 competition!