Combination of Screen-Printed Carbon Electrode and Molecularly Imprinted Polymers for the Selective Determination of Phenolic Compounds in Wine

Abstract

Caffeic acid (CA) is an efficient antioxidant found in wine and in plants and can be extracted from the by-products of the food industry. A molecularly imprinted polymer specific to caffeic acid (CA-MIP) was prepared by radical polymerization using N-phenylacrylamide as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, and azobisisobutyronitrile as the initiator, in the presence of CA as the template molecule. The rebinding activities between the polymers and CA were promoted by an indirect method and characterized by cyclic voltammetry (CV) using a screen-printed carbon electrode (SPCE). It is a fast method, which only requires simple and portable instrumentation. The polymer showed a high selectivity toward CA and a good repeatability. CA-MIP was then applied in wine samples spiked with CA, and the results were compared to those obtained by a chromatographic method. With a limit of detection of 0.06 mM in wine, the recovery values confirmed that the method is suitable for further applications.

Optimization of a Molecularly Imprinted Polymer Synthesis for a Rapid Detection of Caffeic Acid in Wine

“…Two functional monomers were chosen for the synthesis. N-acrylamide was already used in a previous study (CA-MIP1/NIP1) [ 15 ]. Its chemical structure, having an aromatic ring and hydroxyl groups, allows it to form π–π stacking and hydrogen bonds with the template.…”

“…Water used in all experiments was deionized and obtained from an Elga Ionic system PURELAB Option, Vivendi Water, Antony, France. [ 15 ].…”

“…Brunauer–Emmett–Teller (BET) method was used for surface area analysis and was performed by nitrogen adsorption-desorption at a temperature of 77 K using an ASAP 2020 instrument (Micromeritics, Merignac, France). Prior to analysis, 50 mg of the sample was outgassed for 14 h at room temperature [ 15 ].…”

“…The chromatographic separation was achieved with a gradient of two solvents: (solvent A 0.1% v / v acetic acid in water, solvent B 0.1% v / v acetic acid in acetonitrile) 7.5% of B from 0 to 8 min, 95% from 8 to 10 min, and 7.5% from 10 to 12 min. The flow rate was 1.0 mL.min −1 , and detection of CA was performed at 325 nm [ 15 ].…”

“…A rapid method has been presented by Elhachem et al [ 15 ] for the electrochemical detection of caffeic acid using molecularly imprinted polymers (MIP) and screen-printed electrodes and has been applied in wine. This simple and rapid method showed interesting results in terms of selectivity and was validated by a reference method, the HPLC-UV.…”