Sensitive Detection of 8‐Hydroxyquinoline in Cosmetics by Using a Poly(tannic acid)‐Modified Glassy Carbon Electrode

Abstract

AbstractTannic acid (TA) as a natural plant polyphenol bearing multiple phenolic hydroxyl groups could cause considerable interactions with organic compounds. This work aims at detecting 8‐hydroxyquinoline (8‐HQ) based on poly (tannic acid) (PTA) by electropolymerization of TA on glassy carbon electrode (GCE). Owing to enhanced modified electrode surface area and interactions of PTA with 8‐HQ via hydrogen bonding and π‐π stacking, PTA/GCE exhibits electrocatalytic activity to 8‐HQ. Using Differential pulse voltammetry, PTA/GCE shows two linear plots with 8‐HQ concentrations from 0.5 to 5 μmol L−1 and 5 to 50 μmol L−1, the detection limit is 0.036 μmol L−1. The PTA modified electrode also shows great reproducibility and stability. The application of the sensor for real hair conditioner samples is demonstrated with satisfactory result.