Nanocomposites and nanomaterials

Molecularly imprinted polymers as elements of nanosensor colorimetric test system for selective recognition of sulfamethoxazole
Gorbach L.А.1, Purikova O.H.1, Sergeyeva T.A.2, Brovko О.O.1 
1 1Institute of Macromolecular Chemistryof the National Academy of Sciences of Ukraine. Kharkivs’ke shose, 48, Kyiv-02160, Ukraine.
E-mail: gorbachla@ukr.net
2 Institute of Molecular Biology and Genetics of the National Academy of Sciences of Ukraine. Zabolotnogo str., 150, Kyiv-03680, Ukraine.

A colorimetric test system that functions as a "litmus paper" for determining the sulfamethoxazole content in aqueous solutions was proposed. The idea of colorimetric determination was based on the ability of nanostructured molecularly imprinted polymers (MIP) to absorb the analyte molecule with high selectivity and give a colour response to a qualitative reaction between the analyte and the corresponding reagent. Nanostructured sulfamethoxazole-imprinted MIPs from acrylate-urethane polymers were synthesized and successfully used to obtain the colorimetric test systems. The choice of functional monomers for MIP synthesis was performed using computer simulation. Itaconic acid as a functional monomer provided the best absorption capacity of sulfamethoxazole alongside with the highest intensity and stability of MIP staining. The amount of sulfamethoxazole adsorbed from the aqueous solution was controlled by a qualitative reaction with sodium nitroprusside. It is shown that the colour intensity of the polymer film depends on the sulfamethoxazole concentration and varies from red-brown to slightly yellow and persists throughout the year. The stained test systems were compared with control membranes without matrix molecules and nanostructured binding sites of sulfamethoxazole. It was found that the most effective detection limit and the concentration range were 2 mM and (2-15) mM respectively. These parameters were applied for the developed colorimetric test system.