Abstract: The invention relates to a sampling device adapted to be inserted into a hollow tubular endpiece of the needle or catheter type, and to emerge from the endpiece with a view to contact with a bodily fluid containing biological samples to be sampled, to a sampling system incorporating this endpiece and this device, which is mounted so as to slide in the latter, and to a method for manufacturing this device. This sampling device comprises a framework (5) microstructured by openings (5b), and a biocompatible and porous crosslinked polymer layer which comprises capture supports adapted to capture the said targets and which is adapted to retain these supports from the fluid and to let through only fluid particles including these targets with a size of less than a cutoff size, the said polymer layer filling all or some of the said openings, so as to be retained by the said framework.