Polyethylenimine-Based Electrochemical Sensor for the Determination of Caffeic Acid in Aromatic Herbs

An electrochemical sensor based on carbon paste modified with polyethyleneimine was developed and employed for the determination of caffeic acid in aromatic herbs. The prepared by mixing polyethylenimine (1.5% v/v), graphite powder, mineral oil. polyethylenimine-based electrode showed an enhancement charge transfer at electrode–solution interface a higher current intensity reaction acid, comparison to unmodified electrode. calibration plot constructed 0.1 mol L?1 acetate buffer (pH 5.0) square wave voltammetry linear range 1.25 19.9 ?mol limit detection 0.13 L?1, respectively. Finally, proposed monitor accuracy dried Thymus vulgaris Salvia officinalis samples, recovery results from 93 105%.