Towards electrochemical surface plasmon resonance sensor based on the molecularly imprinted polypyrrole for glyphosate sensing

• Published in: Talanta (Oxford) 2022-05, Vol.241, p.123252-123252, Article 123252
• Main Authors: Balciunas, Domas, Plausinaitis, Deivis, Ratautaite, Vilma, Ramanaviciene, Almira, Ramanavicius, Arunas
• Format: Article
• Language: English
• Subjects: Electrochemical Techniques - methods; Electrodes; Glycine - analogs & derivatives; Glyphosate; Herbicide; Molecular Imprinting - methods; Molecularly imprinted polymer (MIP); Polymers - chemistry; Polypyrrole (Ppy); Pyrroles - chemistry; Self-assembled monolayer (SAM); Surface Plasmon Resonance; Surface plasmon resonance (SPR)
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2022.123252

In this research the molecular imprinting technology was applied for the formation of glyphosate-sensitive layer. The glyphosate imprinted conducting polymer polypyrrole (MIPpy) was deposited on a gold chip/electrode and used as an electrochemical surface plasmon resonance (ESPR) sensor. The results described in this study disclose some restrictions and challenges, which arise during the development of glyphosate ESPR sensor based on the molecularly imprinted polymer development stage. It was demonstrated, that glyphosate could significantly affect the electrochemical deposition process of molecularly imprinted polymer on the electrode. The results of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and surface plasmon resonance (SPR) have demonstrated that glyphosate molecules tend to interact with bare gold electrode and thus hinder the polypyrrole deposition. As a possible solution, the formation of a self-assembled monolayer (SAM) of 11-(1H-Pyrrol-1-yl)undecane-1-thiol (PUT) before electrochemical deposition of MIPpy and NIPpy was applied. Dissociation constant (KD) and free energy of Gibbs (ΔG0) values of glyphosate on MIPpy and Ppy without glyphosate imprints (NIPpy) were calculated. For the interaction of glyphosate with MIPpy the KD was determined as 38.18 ± 2.33⋅10−5 and ΔG0 as −19.51 ± 0.15 kJ/mol. [Display omitted] •Molecularly imprinted polypyrrole (MIPpy) based ESPR sensor was designed.•Electrochemical surface plasmon resonance (ESPR) was applied for analytical signal generation.•The polypyrrole layers were deposited using chronoamperometry.•Glyphosate was imprinted within polypyrrole layers in order to design the ESPR sensor.•Two different strategies (structures with and without SAM) were applied for the formation of these MIP-based.