Molecularly imprinted polymers for optochemical sensors

Abstract

ADVANCED MATERIALSCommunications tage. EL originates from the compensated region where the built-in electric field is a maximum. Note, however, that when the external bias is applied under steady state conditions, the external field is opposite to the built-in field so that near threshold, the net internal field is small during operation. The observed decrease in the PL within the junction is particularly interesting since external quantum efficiencies of LECs are comparable with those of polymer LEDs fabricated from the same semiconducting polymer.[lA1 This suggests that the quantum efficiency of the EL is a larger fraction of the PL than in conventional polymer light-emitting diodes.We emphasize once again that the results presented here were obtained with the LEC in the surface cell configuration with relatively widely spaced electrodes. For sandwich cells, the width of the junction must be less than the sub-micron thickness of the polymer layer, implying that the boundary conditions play a more critical role. ExperimentalSurface cell LECs were prepared with pairs of gold strips (5 mm long, 2 mm wide) as the contact electrodes, separated by a (approximately) 20 pm gap. Five pairs were fabricated onto an 1.5 x 1.5 cm2 glass substrate by vapor deposition through a shadow mask. A layer of chromium was

Molecular imprinting science and technology: a survey of the literature for the years up to and including 2003

“…660 The formation of imprinted polyurethanes by the condensation of di-or tri-isocyanates with polyhydroxy-compounds has been relatively successful; in particular the cross-linking of supramolecular complexes of cyclodextrins has been employed in the imprinting of cholesterol, peptides and other templates. 43,[661][662][663][664][665][666] Polyurethane formation has also been widely employed by the group of Dickert to prepare imprinted sensor elements for diverse analytes including solvent vapours, 667 aromatic hydrocarbons, 668,669 halogenated compounds, 670 engine oil 671,672 and yeast cells. 673 Cross-linking of poly(allylamine) with diacylchlorides in an interfacial polycondensation at the surface of an aqueousdispersed organic droplet had earlier been used as the first step in the imprinting of bacteria.…”

Sugar acrylate-based polymers as chiral molecularly imprintable hydrogels

“…Both polymers were characterized by solid state 13 C-NMR and FTIR [ Fig. 1(A,B)] and the results were consistent with their chemical structures.…”

“…Solvent molecules may also function as templates and produce imprinted cavities in MIPs. 13 Because of incorporation of solvent molecules in the imprint cavity during MIP formation, optimal imprinting should occur in the presence of those same solvent molecules and, therefore, in the solvent in which imprinting was performed. Hence, in the present case, the greatest resolution would be expected in DMF.…”

Biomimetic Molecular Recognition Elements for Chemical Sensing

“…One important caveat is that different vinyl groups may be incorporated at different rates in the polymeric system depending on the functionality. An alternative, yet still successful, approach of step-growth polymerization has been used by Dickert et al to make polyurethane-based MIPs with biomimetic recognition capabilities toward sensing a variety of templates including vapor targets [66], oils [67], and even whole cells [68,69]. Among the polymerization systems, one parameter that seems most pertinent is the ratios of monomer, cross-linker, and template, which is typically 8 : 40 : 1 respectively [64].…”