The unmodified and modified by polyaniline and nanoparticles planar potentiometric sensors on the basis of tetradecylammonium associates with a complex silver (I) – cefazolin are created. Optimum ratios of components in carbon-containing ink are established: 30–32% carbon powder, 16–18% polyvinylchloride, 48–50% dibutylphthalate and 1–3% of electrode active compound (EAC). Planar sensors of two types are examined: electrode active compounds, electrode active compound and modifiers were added into in carbon-сontaining ink.
