A highly sensitive and portable fluorescence detector for small volumes of biosamples

We present a stand-alone portable and real-time optical detector which can be used as a biosensor for fluorescently tagged bio-samples. To measure the fluorescence intensity of the target sample, an optical detection structure that excites the sample by an LED and senses the light emitted from the sample was fabricated using a CAD tool and a 3D printer. The microcontroller circuit was designed to control the LED, amplify the detected light signal with low noise, and display the measurement data on a LCD display. The circuit is integrated with a battery so that it operates independently without help of a computer or other peripheral devices. The developed device was used to successfully measure concentration of Shiga toxin causing food poisoning.