Investigation of the binding of dioxin selective pentapeptides to a polyaniline matrix

Polyaniline in form of emeraldine salt and emeraldine base was used as a matrix to attach several labeled and non-labeled dioxin selective pentapeptides both directly to the polymer and using glutaraldehyde as a linker. The peptides have been selected as a model to study the binding process due to their smaller size, lower sensitivity to the environment and potential application as solid state extraction reagents for chlorinated toxins. The composition and the properties of the compounds were investigated by means of elemental analysis, XPS, FTIR, UV/vis, and fluorescence spectroscopy. The results have shown that 3.30–7.76% peptides were attached to the emeraldine base both with and without a linker. Glutaraldehyde and the peptides were connected to the matrix via chemical bond resulting in formation of compounds whit similar composition and stability in a broad pH range. The influence of the linker and the peptides on the electronic properties and composition of the polymer have been investigated by principal component analysis.

► Small peptides form stable bond with PANI matrix with or without GA as a linker.
► Sensors are stable in a broad pH range.
► GA does not contribute to the overall stability of the compounds.
► Attachment to the matrix does not affect the emission properties of the ligands.
► Peptide binding forms new species with different electronic properties.