This project arose from the need to filter the sampled data and eliminate non-useful information in Serial Crystallography in Microfluidic Device (MFD)by using a portable optical detector placed around the channel. By testing sixteen different configurations, always using an LED as a source and a photodiode as a light sensor, changes in the channel due to the passage of air bubbles were detected. These changes corresponded to a 13,25% in relation to the changes due to light switching, with a gain factor of 10,11V/V. However, it was not sensitive enough to detect when a microcrystal passed through it, although it can detect bubbles and opens the door to design such sensors for these applications in the future.