Conjugates of nanoparticles and antibodies are efficient bioanalytical reagents that facilitate the formation and separation of analyte-containing complexes, as well as the generation of detectable signals. In this regard, it is important that the conjugates maintain the functionality of their components and enable the detection of analytes at low concentrations. This report focuses on immunochromatographic test systems (ICTSs), which are widely used for rapid on-site testing. The study considers the parameters of nanolabel-antibody conjugates and the conditions of assays implementation providing the desired detection limits and working ranges of ICTSs in accordance with regulatory requirements for controlled analytes. The target antigens in the ICTSs investigation are veterinary drugs of different classes. Different approaches for varying ICTSs sensitivity are explored, including using new labels, label complexes, and additional chemical reactions, are characterized. Features of spherical and branched gold nanoparticles, magnetite particles, and semiconductor quantum dots as carriers for antibody immobilization are considered. The specific requirements for nanocarriers/nanolabels in ICTSs are outlined. The sensitivity changes of competitive immunoassays with varying sizes of nanoparticles or degrees of their coating by antibodies are discussed. Additionally, alternative ways to modulate the detection limit, such as pre-incubation of reagents, transferring heterogeneous reactions into moving liquids, displacing binding zones, adjusting flow velocity and geometry, and altering the sequence of reagents introduction to reaction mixtures and test strips. Finally, the developed ICTSs for detecting antibiotics of different classes, based on the use of the selected nanoparticles-antibodies conjugates, are presented. Their efficiency for control of raw and processed meat in combination with rapid samples preparation was demonstrated.