NEW APPROACHES FOR THE DEVELOPMENT OF MOLECULARLY IMPRINTED POLYMERS FOR PROTEINS EXTRACTION AND OPTICAL SENSOR DEVELOPMENT

Molecularly imprinted polymers (MIPs) are synthetic antibody mimics that selectively recognize molecular targets. Over the past decade, MIPs have raised increasing attention towards replacing biomolecules as selective recognition elements in sensors and other applications, such as analytical separations. MIPs are highly robust, showing excellent operational stability under a wide variety of conditions. They can be used in organic or in aqueous media and their cost is lower and their preparation is easier than that of antibodies, avoiding the use of laboratory animals or the difficulties associated to the production of antibodies for toxic compounds [1].

Herein we describe the development of MIPs for the selective extraction of peptide-tags that enable easy purification of expressed proteins. The selective recognition polymers were prepared by a non-covalent imprinting approach in the form of spherical microparticles using sacrificial silica beads (40 - 75 μm) to improve the packing efficiency in solid phase extraction (SPE) cartridges. A molecularly imprinted SPE solid phase extraction (MISPE) method has been optimized for the selective extraction of fluorescent recombinant proteins tagged with the selected peptides from cell cultures.

Alternatively, we have explored new sensing mechanisms for the application of MIPs to the development of optical sensors [2]. In the first approach, we have developed a cost-effective optical sensor based on a MIP film integrated on a planar plastic waveguide. The waveguide is made of a conventional Scotch tape, whose sticky side is used to attach the MIP layer.To proof the concept, Rhodamine 6G has been employed as a model analyte/template. Analyte – MIP interaction leads to intensity changes in guided light (sensor response). Selectivity and specificity of the MIP optical sensor have been also studied. The second sensing scheme is based on the synthesis of MIPs doped with a Eu(III) complex and aqua-labile ligands, that upon coordination to tenuazonic acic (TeA), an Alternaria mycotoxin, will yield an increase in Eu(III) typical luminescence at 615 nm. The fact that has a maximum absorption at 276 nm (at 284 nm when complexed to Eu(III)), led us to consider the possibility of using TeA as an antenna ligand for Eu(III) luminescence sensitization. This luminescence increase has been applied to the detection of target mycotoxin in organic solvent.

Acknowledgments

This work was supported by the Spanish Ministry of Economy and Competitiveness (grant CTQ2015-69278-C2-R/AIE), and the European Funds for Regional Development (FEDER).

[1] Molecular imprinting, ed. K. Haupt, Springer, Berlin, 2012.

[2] Moreno-Bondi, M.C., Benito-Peña, E., Carraco, S., Urraca, J.L. Molecularly imprinted polymer based optical chemosensors for selective chemical determinations. In Molecularly Imprinted Polymers for Analytical Chemistry Applications, RSC Polymer Chemistry Series Vol. 28, Kutner, W.; Sharma, P.S., Eds.; Royal Society of Chemistry; Croydon, UK, 2018, pp. 227–281, ISBN 978-1-78262-647-3.