Abstract
We describe an optical system that detects the presence of E.
coli bacteria, making use of the bacteria’s natural
fluorescence properties. The system provides an excitation signal at
365 nm and detects the emission signal, from the bacteria, at
approximately 445 nm. The system also allows the intensity of
the emitted signal to be compared with a user-programmable threshold.
This allows rapid testing of many samples in a laboratory setting.
Complete setup and performance details are provided, enabling the
experimentalist to tailor the system parameters to other species of
microorganisms, which may have fluorescence properties at other
wavelengths.