Synthesis of molecularly imprinted polythiophene

Abstract

Williamson etherifications of diethyl 3,4-dialkoxythiophene-2,5-dicarboxylate (DDTD) yielded the desired thiophene dicarboxylate derivatives (3) in up to 87% yield. Hydrolysis of these diethylesters afforded the diacids (4) in up to 96% yield. One pot synthesis by combining decarboxylation and bromination steps was carried out giving the dibromo product (7b) in 77% yield, higher than that was obtained from the corresponding separated steps. Molecularly Imprinted polymers (MIPs) based on PEDOT were prepared from monomer (7b) by solid state Polymerization (SSP) in the presence of templates molecules: 2,4,6-trinitrophenol (TNP) or 2,4,6-trinitrotoluene (TNT). The resulting conjugated MIPs exhibited the recognition of its template Molecules compared to non-imprinted polymers (NIPs) in the binding experiments monitored By UV-Vis spectroscopy. The result was found that the specific adsorption (ΔQ) of TNP and TNT molecules bound to the MIPs were 128.41 and 103.63 µmol/g, respectively. The rebinding capacities of the TNP MIPs were 38.64% for TNP-MIPs and 28.63% for TNT-MIPs. Cross binding experiments confirmed the selectivity of the MIPs only towards their template molecules. These result showed that PEDOT could be imprinted and developed to be sensors for specific detection of detected of selected template compounds.