Polydopamine-based molecularly imprinted thin films for electro-chemical sensing of nitro-explosives in aqueous solutions

Nadja Leibl (1) , Luminita Duma (2, 1) , Carlo Gonzato (1) , Karsten Haupt (1)

1 GEC - Génie Enzymatique et Cellulaire
2 CNRS - Centre National de la Recherche Scientifique

A sensitive electrochemical sensor was developed for the detection of nitro-explosives in aqueous solutions based on thin molecularly imprinted polydopamine films. Dopamine was identified in silico, based on DFT (density functional theory) calculations with the ωB97X-D/6-31G* basis set, as the best functional monomer and electropolymerized via cyclic voltammetry (CV) in the presence of carboxylic acid-based structural analogues ('dummy' templates) for two model nitro-explosives: TNT (2,4,6-trinitrotoluene) and RDX (Research Department eXplosive, 1,3,5-trinitroperhydro-1,3,5-triazine). This approach afforded a homogenous coverage of gold electrodes with imprinted films of tunable thickness. The electropolymerized molecularly imprinted polydopamine films allowed for a 10 5-fold sensitivity improvement over a bare gold electrode based on tracking the redox peaks of the targets by CV. This improved sensitivity is ascribed to the ability of the MIP to concentrate its target in proximity to the transduction element. The MIP films showed reproducible binding in phosphate buffer (10 mM, pH 7.4), with a dynamic range from 0.1 nM to 10 nM for both TNT and RDX and an increased selectivity over closely related structural analogues.

Mots clés: Nitro-explosives; 2,4,6-trinitrotoluene; RDX; polydopamine; thin films; chemosensor; electropolymerization; molecularly imprinted polymers; cyclic voltammetry

Domaines: Polymères

Nadja Leibl, Luminita Duma, Carlo Gonzato, Karsten Haupt. Polydopamine-based molecularly imprinted thin films for electro-chemical sensing of nitro-explosives in aqueous solutions. Bioelectrochemistry, 2020, 135, pp.107541. ⟨10.1016/j.bioelechem.2020.107541⟩. ⟨hal-02881036⟩