Class-specific SERS-based determination of sulfanilamide antibiotics in body fluids
Natalia E. Markina, Alexey V. Markin; Saratov State University, Saratov, Russia
Abstract
SERS-based analysis of real objects often uses new SERS substrates and/or complex analysis procedures (e.g. sample pretreatment), and they are optimized for the determination of only one analyte. Moreover, simplicity and selectivity of analysis are often overshadowed by maximum (sometimes unjustified) sensitivity. As a result, this tendency limits the versatility of SERS analysis and complicates its practical implementation.
Therefore, this work reports (i) the results of SERS study of five representatives of sulfanilamide antibiotics (SAAs) and (ii) the universal, but simple SERS assay capable for determination of SAAs in different body fluids (urine and saliva). Here acidification promotes the formation of SERS spectra with maximum intensity and similarity that is connected with enhancement of the protonated sulfanilamide fragment (a structurally similar part of the SAAs) due to its strong electrostatic interaction with the SERS-active surface. Also, improvement in assay sensitivity and selectivity by simple addition of cationic polyelectrolyte (polydiallyldimethylammonium chloride) has been demonstrated and theoretically explained. Meanwhile, standard silver nanoparticles reduced and stabilized with hydroxylamine were used in the work to simplify the analysis protocol and its verification. Therefore, the assay allows for precise and accurate class-specific determination of SAAs in urine and saliva in the therapeutically relevant ranges.
The work was supported by the Russian Science Foundation (project 23-23-00236).
Speaker
Natalia E. Markina
Saratov State University
Russia
Discussion
Ask question
