Modified planar sensors for the separate detection of certain cephalosporin antibiotics

Modified screen-printed potentiometric sensors sensitive to cephalosporin antibiotics – cefuroxime (Cefur), cefotaxime (Ceftx), cefazolin (Cef) have been developed. Tetradecylammonium associates with complex compounds silver (I) – cefuroxime (cefotaxime) have been used as electroactive components. The role of magnetic nanoparticles Fe3O4 and cetylpyridinium chloride in improving the electroanalytical properties of sensors in solutions of the studied antibiotics is shown. Optimal ratios of modifiers in carbon-containing inks (Fe3O4 : CPCh = 1 : 2.5) have been found. The main electroanalytical characteristics of the modified sensors are determined. The introduction of a binary mixture of magnetic nanoparticles and cetylpyridinium chloride into carbon-containing inks leads to an improvement in the electroanalytical properties of planar sensors sensitive to cefuroxime, cefotaxime, cefazolin: at the same time, the detection limit of 1 · 10-6 (1 · 10-7 M) decreases, angular coefficients (55 ± 3 mV/pC) and linearity intervals of electrode functions (1 · 10-6 – 1 · 10-2 M), the response time is reduced – 26–30 seconds. The adsorption of surfactants at the interface ensures the stability of the suspension of nanoparticles and allows the concentration of analyte molecules. The possibility of separate determination of cephalosporin antibiotics in two- and three-component mixtures by projection methods of multidimensional data processing PLS-1 and PLS-2 is shown. The standard errors of calibration and prediction are estimated, on the basis of which the optimal number of latent variables for these methods is selected. It is established that all the studied models give high values of correlation coefficients and tangents of the slope of the “measured-predicted” dependencies close to one, which makes it possible to recommend these methods for practical use.