Electrochemical sensing of sodium dehydroacetate in preserved strawberries based onin situ pyrrole electropolymerization at modified carbon paste electrodes.

Sodium dehydroacetate (SDA) is one of the most common additives and preservatives in food, especially for strawberries, due to its fungicidal and antibacterial effects. Therefore, an innovative electrochemical sensor, depending on carbon paste electrode (CPE) modulated with multi-walled carbon nanotubes and molecularly imprinted polymers, was constructed for in situ detection of SDA. Based on density functional theory calculations, the polymer film was imprinted on the modified CPE surface via electrochemical polymerization of pyrrole in the presence of SDA. The morphology and electrochemical behavior of the synthesized sensors were characterized using different techniques. Under optimal conditions,a wide linear range (4.1 × 10 -1.2 mM)with a detection limit of 0.13 nM was obtained using differential pulse voltammetry and electrochemical impedance spectroscopy. The proposed sensor displayed superb selectivity for SDA, good precision (RSD = 2.7%), and high stability (˃4 weeks). Thus, it was successfully applied to determine SDA in strawberry samples with excellent recoveries (96.7%-100%).