Details

Autor(en) / Beteiligte

• Moro, Giulia
• Bottari, Fabio
• Sleegers, Nick
• Florea, Anca
• Cowen, Todd
• Moretto, Ligia Maria
• Piletsky, Sergey
• De Wael, Karolien

Titel

Conductive imprinted polymers for the direct electrochemical detection of β-lactam antibiotics: The case of cefquinome

Ist Teil von

• Sensors and actuators. B, Chemical, 2019-10, Vol.297, p.126786, Article 126786

Ort / Verlag

Lausanne: Elsevier B.V

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] •Cefquinome electrochemical fingerprint allows its identification in the nanomolar range.•Conductive imprinted polymers are obtained by electropolymerization of 4-amino benzoic acid.•The synergistic contribution of MWCNTs and MIP is crucial to achieve higher sensitivity.•Under optimum conditions, the lower detectable CFQ concentration on the sensor is 50 nM. A biomimetic sensor for cefquinome (CFQ) was designed at multi-walled carbon nanotubes modified graphite screen-printed electrodes (MWCNTs-G-SPEs) as a proof-of-concept for the creation of a sensors array for β-lactam antibiotics detection in milk. The sensitive and selective detection of antibiotic residues in food and environment is a fundamental step in the elaboration of prevention strategies to fight the insurgence of antimicrobial resistance (AMR) as recommended by authorities around the world (EU, WHO, FDA). The detection strategy is based on the characteristic electrochemical fingerprint of the target antibiotic cefquinome. A conductive electropolymerized molecularly imprinted polymer (MIP) coupled with MWCNTs was found to be the optimal electrode modifier, able to provide an increased selectivity and sensitivity for CFQ detection. The design of CFQ-MIP was facilitated by the rational selection of the monomer, 4-aminobenzoic acid (4-ABA). The electropolymerization process of 4-ABA have not been fully elucidated yet; for this reason a thorough study and optimization of electropolymerization conditions was performed to obtain a conductive and stable poly(4-ABA) film. The modified electrodes were characterized by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and cyclic voltammetry (CV). CFQ-MIP were synthesized at MWCNT-G-SPEs by electropolymerization in pH≈1 (0.1 M sulphuric acid) with a monomer:template ratio of 5:1. Two different analytical protocols were tested (single and double step detection) to minimize unspecific adsorptions and improve the sensitivity. Under optimal conditions, the lowest CFQ concentration detectable by square wave voltammetry (SWV) at the modified sensor was 50 nM in 0.1 M phosphate buffer pH 2.