DIY Spectrophotometer

thingiverse

The parts listed below can be used to build a basic spectrophotometer, which shines an LED on a sample in a cuvette and then measures how much light passes through the sample with a photoresistor (on the opposite side of the cuvette). The Arduino measures the voltage across the photoresistor. In short, as the absorbance of the sample increases, the voltage across the photoresistor will decrease. Several parts are listed below, including: 1) An enclosure that will hold an Arduino and the rest of the LED/photoresistor circuit. 2) A simple cuvette holder that grips the cuvette and holds the LED/photoresistor in place on either side of it. 3) A more advanced cuvette holder with multiple pieces (LED holder, cuvette/photoresistor holder, and a cuvette removal tool), which fully conceals the cuvette from ambient light.