A novel molecularly imprinted electrode modified with carbon nanohorn and polydopamine for highly sensitive determination of erythrocin in food

In order to achieve a simple and rapid analytical method for determination of erythromycin (Ery) residues in food, an erythromycin molecularly imprinted membrane modified electrode (Ery-MIM/pDA/CNHs/GCE) was developed by sequentially modifying glassy carbon electrode (GCE) with carbon nanohorns (CNHs), polydopamine (pDA) and erythromycin molecularly imprinted membrane (Ery-MIM) via dropcoating of CNHs, electropolymerization of dopamine, and electropolymerization of 2-aminopyridine in the presence of Ery , respectively. In this work, CNHs was used as electrical signal amplification element due to its large surface area and excellent conductivity, and pDA was used as adhesive because of its high adsorption capacities. As expected, the resulting Ery-MIM/pDA/CNHs/GCE exhibits high sensitivity, good selectivity, excellent repeatability and stability. A linear response for the determination of Ery by Ery-MIM/pDA/CNHs/GCE was obtained in the concentration range of 1.0 × 10 -5  ∼ 1.0 × 10 -8 mol L -1 ( r 2  = 0.9810) with the detection limit of 2.7 × 10 -9 mol L -1 (S/N = 3). The electrode was used to detect Ery in food samples with satisfied recoveries of 95.4%∼103.0% and RSD below 6.0%.