Biotin is a vitamin that can be coupled to different types of biomolecules being still recognized by strept(avidin), due to the high affinity constant between them (Ka = 10^15 M^-1). This strong streptavidin-biotin interaction is extremely useful to attach biotinylated biomolecules onto solid support or inorganic materials (including magnetic and metallic nanoparticles, transducing materials, and platforms). Biotinylation provides a versatile tool for tagging biomolecules in order to achieve optical, fluorescence or electrochemical readout with enhanced sensitivity. This interaction has been used for years in many bioanalytical methods, including DNA-based methods and immunoassays. In this way, immunoassays were developed for analyses of different type of analytes - food and water contaminants, bacteria, specific protein of some diseases, etc. Immunoassays are based on antigen-antibody recognizing interaction, usually using the antigen as analyte and antibody as recognizer; and these assays can be of different types. Two immunoassays system that can be cited due to their high importance: Enzyme-Linked Immunosorbent Assay (ELISA), it has been widely used through the decades; and Lateral Flow Assays (LFA), more recently employed. The use of biological materials such as antibodies, proteins, or enzymes in bioanalysis is costly and often unstable in adverse conditions. An interesting and feasible idea is the synthesis of materials that can mimic the biological interactions of recognition; what has been done successfully by molecularly imprinted polymers (MIP). The high stability of theses polymer allows them to be used in extreme conditions of analysis (conditions that biomolecules commonly do not support) and modified with different materials; as magnetic nanoparticles, increasing the recognition performance of the MIP. Furthermore, it is also possible to functionalize the surface of polymer with functional groups or molecules, so that it carries out exclusion of high molecular weight molecules such as proteins; becoming a restricted access material (Restricted Access Molecularly Imprinted Polymer - RAMIP). Thus, this project aims to develop selective analysis systems of LFA and ELISA with molecularly imprinted polymers replacing antibodies, which are commonly used in these tests. For this, the polymers synthesized previously will be immobilized on the LF strip by different routes (occlusion or covalent methods); and to ELISA, analysis parameters will be optimized and the MIP recognize performance will be compared in relation with antibodies.The developed devices, after properly characterized and with optimized parameters (selectivity, interaction time, etc.) will be applied in identification and quantitation of biotin and biotinylated DNA of E. coli in different types of samples.This internship will be very important in the academic formation of MSc. student, due to allow the learning of techniques used in bioanalysis, which is the research area of Prof. Isabel Pividori.
News published in Agência FAPESP Newsletter about the scholarship: