Effect of Magnetic Nanoparticles and Cetylpyridinium Chloride on Electroanalytical Properties of Planar Sensors for Cefuroxime and Cefotaxime

Abstract

We have developed planar potentiometric sensors for cephalosporin antibiotics: cefuroxime and cefotaxime. Tetradecylammonium associates with silver(I)–cefuroxime (cefotaxime) complexes were used as electrode-active components. The linear range of the electrode function of the unmodified sensors is 10^–5 (10^–4) to 10^–2 mol/L, its slope is 46 ± 6 mV/pC, and the response time of the sensors is 40 s. Fe₃O₄ magnetic nanoparticles and cetylpyridinium chloride (CPCh) have been shown to improve electroanalytical properties of the sensors in cefuroxime and cefotaxime solutions. We have optimized the ratio of the modifiers in carbon-containing ink (Fe₃O₄ : CPCh = 1 : 2.5) and evaluated the principal electroanalytical characteristics of the modified sensors. The addition of a binary mixture of magnetic nanoparticles and cetylpyridinium chloride to carbon-containing ink lowers the detection limit for cefuroxime and cefotaxime to 10^–6 mol/L (10^–7 mol/L), increases the slope (55 ± 3 mV/pC) and linear range (10^–6 to 10^–2 mol/L) of the electrode function, and reduces the response time of the sensors to 26–30 s. Interfacial surfactant adsorption ensures stability of nanoparticle suspensions and enables preconcentration of analyte molecules. Electrostatic and hydrophobic interactions with surfactants increase solubility of organic compounds. We have demonstrated that modified screen-printed sensors can be used for determination of cefuroxime and cefotaxime in medications and model aqueous solutions containing additions of antibiotics.