Supramolecular Complexation of Biogenic Amines by Functional Electroactive Monomers of Thiophene Derivatives for Formation of Molecularly Imprinted Polymer (MIP) Films for Biosensor Development
Altro
Data di Pubblicazione:
2010
Citazione:
Supramolecular Complexation of Biogenic Amines by Functional Electroactive Monomers of Thiophene Derivatives for Formation of Molecularly Imprinted Polymer (MIP) Films for Biosensor Development / A. Pietrzyk, W. Kutner, S. Suriyanarayanan, R. Chitta, E. Maligaspe, M.E. Zandler, F. D’Souza, F. Sannicolò, P.R. Mussini. ((Intervento presentato al 43. convegno Heyrovský Discussion Electrochemistry of Organic Molecules and nCoordination Compounds tenutosi a Trest (Czech Republic) nel 2010.
Abstract:
We synthesized electronically conducting polymers for devising selective chemical
sensors. Toward that, electroactive functional monomers were derivatized to bear
recognition sites capable of formation of complexes in solution with target analytes.
These monomers included derivatives of bis(2,2'-bithienyl)methane substituted with
either the 18-crown-6, 3,4-dihydroxyphenyl, or dioxaborinane moiety. The analytes
were selected from biogenic amines. These included adenine, dopamine, histamine, and
melamine. By DFT quantum chemistry calculations at the B3LYP/3-21G(*) level, we
modeled geometries of these complexes. Initially, the analytes played a role of
templates. Then, the complexes were electropolymerized in the presence of suitably
selected cross-linking monomers and porogenic solvents. A derivative of 3,3-
bithianaphthene and an ionic liquid suited that purpose very well. Next, the resulting
molecularly imprinted polymer (MIP) films were washed with abundance of a base
solution to extract the templates. That way, molecularly imprinted cavities were left in
the MIP film. Size and shape of these cavities were compatible to those of the analyte
molecules. In this form, the film was suitable for use as a recognition material in a
chemosensor. A 10-MHz thickness-shear-mode bulk-acoustic-wave resonator of a
quartz crystal microbalance was used as the piezoelectric transducer of the detection
signal into the mass change signal. The MIP-template interactions of the covalent bond,
hydrogen bond, and inclusion complex nature appeared to be reversible allowing for
extensive and reversible accumulation of the analyte in the film and its subsequent
removal for the analytical reuse. Due to this accumulation, detection limits reached the
nanomole concentration level. Imprinting of the adenine, dopamine, and histamine
electroactive analytes required preliminary coating of the electrode with a barrier
underlayer film. This film served to prevent electrode processes of the analytes on the
one hand and to afford efficient charge exchange with the MIP film deposited by
electrochemical polymerization on top of the barrier film on the other. The electrode
processes of the analytes were highly undesired because adsorption of products of these
processes would be imprinted instead of the analytes themselves. Moreover, products of
these processes would adsorb on the electrode surface blocking it and obstructing
adhesion of the MIP film. Selectivity of the imprinting was tested by using typical
interfering compounds structurally or functionally analogous to the analytes. This
selectivity was high being mainly governed by complementarity of the stereo geometry
of the analytes and imprinted molecular cavities of MIPs as well as affinity of the MIP
binding sites located in these cavities to the binding sites of the analytes.
Tipologia IRIS:
14 - Intervento a convegno non pubblicato
Elenco autori:
A. Pietrzyk, W. Kutner, S. Suriyanarayanan, R. Chitta, E. Maligaspe, M.E. Zandler, F. D’Souza, F. Sannicolò, P.R. Mussini
Link alla scheda completa: