To avoid using labor- and instrumental-intensive methods to detect residues of antibiotics in liquid samples, a competitive lateral flow device was developed using a commercially purchased polyclonal antibody raised against ampicillin-BSA. -lactam-protein conjugates, employing bovine serum albumin, ovalbumin, and keyhole limpet hemocyanin as carrier proteins, and tetracycline-BSA conjugates intended for use as test line capture reagent were synthesized. Those were characterized by LDS-PAGE and the 2,4,6-trinitrobenzene sulfonic acid assay in this research. Haptens were coupled to carrier proteins via the N-hydroxysuccinimide active ester method, the carbamate linkage method, or the diazonium conjugation method. Penicillin G-BSA conjugates with a coupling ratio of 1:50 were used to set up the competitive antibody-based lateral flow device. Initial experiments resulted in a detection limit of 0.3 ppb and a limit of quantification of 0.6 ppb using penicillinG as analyte. Thus, the polyclonal antibody against ampicillin-BSA could be the basis for further investigations. As detector reagent, 40nm gold nanoparticles with an UV/Vis absorption spectroscopy maximum of 529 nm were used. Gold solution titration experiments figured out that coupling of 8 g anti-ampicillin-BSA antibody/mL colloidal gold resulted in stable gold conjugates. By contrast, the commercially obtained protein A purified anti-tetracycline antibody was not able to stabilize colloidal gold particles. Moreover, a soluble derivative of the penicillin binding protein 2x from Streptococcus pneumonia was expressed as a recombinant glutathione S-transferase fusionprotein in Escherichia coli BL21(DE3) in order to design a receptor-based strip test. Nevertheless, it was figured out that the unstable fusionprotein did not lead to PBP2x* or PBP2x*-GST labeled gold nanoparticles, since only the GST-tag moiety of the fusionprotein preferably bound to gold nanoparticles.