TY - CONF A1 - Kislenko, Evgeniia A1 - Wagner, Sabine A1 - Biyikal, Mustafa A1 - Rurack, Knut T1 - Molecularly Imprinted Polymers for Fluorescence Sensing of the Herbecide 2,4-D N2 - Application of pesticides is ubiquitous to better manage agricultural production. However, most of these compounds are harmful or toxic for humans and highly persistent in the environment, even in the crops themselves. Therefore, the rapid and reliable monitoring of pesticide residues is a very important area of environmental analysis. If conducted directly in the field, the use of fluorescence sensing methods is particularly attractive, because they allow for sensitive and rapid analyses while being very versatile. Recently, molecularly imprinted polymers (MIPs) have emerged as promising candidates for the primary sensing phase. Their robustness, low price and tunability render them an attractive alternative to more conventional biosensors based on antibodies. At present, a number of MIP formats are available besides the initial bulk polymer monoliths. Core/shell micro- and nanoparticles are especially suitable for sensor applications. A thin shell provides many advantages compared to a bulk polymer, such as fast diffusion of analyte, homogeneity of binding cavities and a higher number of binding sites closer to the surface. A strategy for sensory MIP synthesis is to introduce the fluorophore covalently into the polymer layer. The fluorescent probe monomer may thus consist of a fluorophore unit, a polymerizable unit and a recognition unit. One of the issues in targeting acidic pesticides such as 2,4-D is the fact that usually their deprotonated form is used for imprinting in organic solvents, commonly as the tetraalkylammonium salt. This approach harbours drawbacks when it comes to analytical rebinding, because real samples seldom contain such counterions. In our group, we have thus developed a new fluorescent probe monomer containing the 2-aminopyridine moiety, which forms strong enough intermolecular hydrogen bonds with the carboxylic acid group of neat 2,4-D. During a titration of the probe monomer with the analyte, hydrogen bond formation is indicated by spectral shifts and fluorescence enhancement. Crystallography studies verified complex formation. The higher fluorometric response of the core-shell MIP compared to a non-imprinted control polymer proved successful imprinting. Here, we will discuss the pros and cons of neutral molecule vs. salt imprinting, potentially expanding the possibilities of fluorescent sensory MIPs. T2 - MIP2018 CY - Hebrew University, Jerusalem, Israel DA - 24.06.2018 KW - Molecularly imprinted polymers KW - 2,4-D KW - Fluorescence KW - Sensing PY - 2018 AN - OPUS4-45598 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -