PIEZOELECTRIC SENSOR COATING BASED ON MAGNETIC CARBON NANOCOMPOSITES Russian patent published in 2022 - IPC H01L41/00 B82B3/00 

FIELD: analytical chemistry.

SUBSTANCE: invention relates to the field of analytical chemistry and can be recommended for the selective determination of ciprofloxacin in foodstuffs and biological fluids using a piezoelectric immunosensor. The determination of the antibiotic is carried out in a competitive immunoassay format using a piezoelectric sensor, the receptor coating of which is formed through the use of a magnetic carbon nanocomposite. Carboxyl groups on the surface of a magnetic carbon nanocomposite were activated with a mixture of N-ethyl-N'-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysuccinimide in 1% Triton X-100 solution by keeping for 20 min. Then the protein conjugate of ciprofloxacin was immobilized on the surface of the nanocomposite, after which the piezoelectric sensor was modified. To do this, 2 mcl of nanocomposite was applied to the surface of a quartz resonator, the material was fixed due to an external magnetic field created by a neodymium magnet. The coated sensor was kept at room temperature for 90 minutes. Before the determination of fluoroquinolone, a fixed amount of antibodies was injected into the sample, the resulting mixture was kept for 20 minutes, after which it was applied to a sensor with a pre-formed receptor coating on the surface of its electrodes. The analytical signal is inversely proportional to the concentration of the detected fluoroquinolone in the analyzed sample, the concentration was determined according to the calibration schedule, the regeneration of the receptor coating was carried out by applying a 0.003 M solution of potassium rhodanide to the surface.

EFFECT: simplification of the procedure for forming the piezoelectric sensor coating, reduction of preparation time for analysis, extension of the service life of the piezoelectric sensor, measurements with the possibility of regeneration of the recognition layer.

1 cl, 6 ex