Using Carbon Quantum Dots for the Determination of Aminoglycoside Antibiotics by Fluorescence Polarization Immunoassay

Conditions are studied for the synthesis of carbon quantum dots (CQD) exhibiting green fluorescence by the ultrasonic treatment of multilayered carbon nanotubes in a mixture HNO3 with H2SO4 (CQD-1) and by the microwave decomposition of 9,10-dinitroanthracene in ethanol (CQD-2). The sizes of COD are estimated by atomic force microscopy, and their optical properties, by spectrophotometry and fluorescence spectrometry. Infrared spectrometry was used to identify active functional groups on the CQD surface, participating in the formation of stable bonds in the synthesis of tracers. A possibility of using CQD as labels in fluorescence polarization immunoassay (FPIA) is shown. Procedures are developed for determining aminoglycoside antibiotics gentamycin, streptomycin, and amikacin by FPIA using a TDx-analyzer (Abbott Diagnostics, United States); their performance characteristics are presented. The limit of detection is (ng/mL) 20, 10, and 3, and the analytical range (mu g/mL) is 0.05-3.00, 0.02-6.00, and 0.01-3.00 for gentamycin, streptomycin, and amikacin respectively. The procedures are tested in the determination of gentamycin, streptomycin, and amikacin in dairy products.