Determination of streptomycin sulfate and neomycin sulfate in liquid media using an amperometric sensor modified with a molecularly imprinted polymer

Molecularly imprinted polymers (MIPs), known for their high specificity and durability, have emerged as promising materials for the development of eco-friendly sensor platforms capable of detecting pharmaceutical compounds in complex matrices. In this work, amperometric sensors based on MIP were obtained for determination of streptomycin sulfate (Strep) and neomycin sulfate (Neo) antibiotics. Both sensors, MIP-Strep and MIP-Neo, demonstrated a linear dependence of the current difference on concentration in the range of 1.0.10–1–1.0.10–5 g/dm3. The detection limits of the analytes by the sensors were 5.8.10–6 g/dm3 (MIP-Strep) and 7.2.10–6 g/dm3 (MIP-Neo), which are below the maximum permissible concentrations. MIP-Strep and MIP-Neo sensors demonstrated high selectivity for their target molecules. The ability of the sensors to selectively recognize target molecules was estimated using the imprinting factor. For MIP-Strep the imprinting factor (IF) was 4.3, and for MIP-Neo – 6.3. Low sensitivity of the sensors to other antibiotics (sodium ceftriaxones, sodium cefazolins) was established. The sensors demonstrated high selectivity: MIP-Strep – to streptomycin, and MIP-Neo – to neomycin, even in binary solutions. The “introduced – found” method established high accuracy of MIP-Strep and MIP-Neo amperometric sensors in determining antibiotics with a relative standard deviation (Sr) ≤ 5%. HPLC was used as a reference method to check the correctness of Strep and Neo determination by amperometric sensors with MIP. It was found that there were no statistically significant differences between the results of the two methods for determining antibiotics. This opens up prospects for using MIP-based sensors for food quality control, especially for detecting target antibiotics in milk and dairy products. Thus, when analyzing milk samples using HPLC and MIP sensors, Strep and Neo were not detected.