Recognition and Determination of Sulfonamides by Near-IR Fluorimetry Using Their Effect on the Rate of the Catalytic Oxidation of a Carbocyanine Dye by Hydrogen Peroxide
I. A. Stepanova, A. N. Lebedeva, Anna V. Shik, Evgenii V. Skorobogatov, Михаил К. Беклемишев
Abstract
Abstract The work aims at developing fluorimetric methods used for bioassay to expand the range of the determined low-molecular-weight organic analytes and cut down sample preparation operations using available fluorophores, reagents, and identical fluorimetric systems for qualitative and quantitative analysis. We proposed using the reaction of carbocyanine fluorophore oxidation by hydrogen peroxide, catalyzed by copper(II), changing fluorescence intensity in the near-IR region (700 nm). Several organic compounds of different nature accelerate or slow down the indicator reaction, to varying degrees, and at different times of the process. The model analytes were eight sulfonamides, which can be distinguished qualitatively using the kinetic factor in data processing by principal component analysis. We demonstrated on an example of phthalylsulfathiazole that the signal could be obtained not only in an aqueous solution but also in the presence of a turkey muscle homogenate at a level of 0.08–0.5 mM (RSD = 9%) without separation. The prospects for the development of such fluorescence platforms are discussed.