Fluorescence is a commonly used signal in biology. Therefore, we successfully designed a machine for the efficient measurement of fluorescence. Handling our machine is so simple that it can be used by family doctors.
Fluorolion is a box which allows a detection of fluorescence with the help of a cell phone. The special feature: By means of three pumps, which transfer the required lysates one after the other into the Petri dish inside the box at the push of a button, the effort could be minimized. This also makes the use of Fluorolion very simple and easy to understand for everyone. The few steps, the simple understanding of the application as well as the small format make our box perfect for the doctor's office.
To use Fluorlion, a Petri dish containing the sample to be examined is first placed in the drawer and then pushed into the box. By pressing the button, the lysates of the three components of our system are pumped into the Petri dish inside the box. Now a photo can be taken after 30 seconds with the help of the flash light function. Now, the result can be seen in the picture. Yellow = No antigen present. Cyan = Antigen present.
Picture shows the first version of the Fluorolion box without automatic filling function. More details about the engineering process can be found here: Engineering
The "Autodesk Inventor" program was used to design the 3D model. Simple geometries such as squares and circles are combined in such a way that they represent a complete 3D model of the device. In order to print the model, it must be exported via Inventor as an ".stl" file. This is uploaded to the "PrusaSlicer" program. This program calculates the optimal path for printing. In addition, properties regarding the print can be set. For example, an infill value of 5% was chosen to save as much plastic as possible, to minimize the printing time as well as to save costs. The quality and stability were still adequate. The box was printed with a Prusa 3D printer. The material used is polylactide (PLA), which is one of the most common filaments in 3D printing.
For the addition of the three components into the petri dish with the sample the pumps need to be controlled by a microcontroller. All this electrical compounds need electrical energy. The circuit as well as the source code is descriped in the figure below. The 9 V battery could be replaced by a AC/DC converter, to power the pumps via a socket. The same could be done for the arduino microcontroller.
Finally, we would like to thank Martin Johann, who enjoys 3D design in his spare time and was able to provide us with the necessary knowledge through his mechanical engineering studies. Through his time-consuming help we were able to construct the box.