OK, I have a new design in mind. I will use Calcein as a DNA detection dye, and use a UV led and green photosensor to detect is the reaction has occured.

The parts I plan on ordering from Mouser are:

Intersil ISL29035IROZ-T7

Light to Digital Converters Integrated Digital Light Sensor

and

Vishay Semiconductors VLMU3100-GS08

405nm SMD UV LED

I was planning on using a temp sensor from Microchip, the:

Microchip Technology MCP9805T-BE/MC

Board Mount Temperature Sensors Ser output temp sensor

But Mouser doesn't have them in stock :( So now I have to find another.