Determination of catechol in tea based on the inhibition of CS@Cd composites electrochemiluminescence

Abstract

To address growing concerns about food safety, sensors for catechol (CA) have been urgently needed. In this work, cadmium-coated carbon spheres (CS@Cd) composites are prepared via hydrothermal synthesis and further used to fabricate a CS@Cd modified glassy carbon electrode (CS@Cd/GCE). Importantly, CS@Cd has good sensitization effect on the electrochemiluminescence (ECL) of luminol-H2O2 system. Besides, CA is able to inhibit the ECL of CS@Cd/GCE owing to the consumption of H2O2 induced by CA, and thus a novel strategy for ECL detection of CA is formulated. At optimum conditions, CS@Cd/GCE exhibits good linear relationship in the range of 1.0 × 10-11 ∼ 1.0 × 10-4 mol·L-1 with a low limit of detection of 2.5 × 10-12 mol·L-1 (S/N = 3). Finally, this method achieves a satisfactory outcome for the detection of CA in tea samples.