/International audienceNowadays, STIs constitute a major public health issue. Indeed, treatments are often started too late because of belated diagnosis resulting in health problems, such as sterility. If prevention is probably the most effective action one can take to prevent the spread of STIs, early detection could help limit their deleterious effects. In this work, a new diagnosis approach based on aptamers is presented. Bound to paper, they allow the detection of HIV and Hepatitis B biomarkers from a blood sample. The associated device is composed of an anchor, the streptavidin protein, allowing the fixation of the aptamer to the paper via biotin (see graphical abstract). With this system, the HIV-1 Reverse Transcriptase (BBa_K1934060 and BBa_K1934061: protein subunits p51 and p66) and HBsAg (surface antigen of Hepatitis B) are specifically targeted. Then, the biomarker/aptamer complex is detected by two methods. The first one is based on fluorescence. As a proof of concept, a paired ATP/aptamer was used and enabled to successfully detect ATP up to 10 µmol.L-1. However, the signal was not detectable with naked eyes or with a cell phone equipped with blue and green filters either. Therefore, a lateral flow assay with nano-sized latex black beads was tested. This second technique showed that a protein biomarker, such as thrombin, could be complexed with latex beads coated with aptamers, in liquid. Finally, the ultimate step, migration of the latex beads inside paper, needs further optimization. Moreover, to easily handle several STI-tests on a single paper strip, an innovative bio-sourced PLA casing was designed and 3D printed to offer an additional intuitive user-interface