Fluorescence spectrophotometry is a technique that analyze the state of sample (normally a biological system) by studying its interactions with fluorescent probe molecules. This interaction is monitored by measuring the changes in the fluorescent probe optical properties. The measurement of fluorescence signals provides a sensitive method of monitoring the biochemical environment of a fluorophore. Fluorophores are polyatomic fluorescent molecules. Instruments have been designed to measure fluorescence intensity, spectrum, lifetime and polarization. The apparatus is equipped with several advanced facilities that can be used for the measurement of a large range of samples. This can also be used measure to understand complex biological processes and enzyme inhibition mechanism. Dyes, LEDs, tracers, solar cells, and organic electroluminescent materials can be analyzed using this technique.