Highly sensitive electrochemical sensor for toxic ractopamine based on the enhancement effect of acetylene black nanoparticles

Abstract

A highly sensitive electrochemical sensor for toxic ractopamine (RAC) was developed using an acetylene black (AB) nanoparticle-modified glassy carbon electrode (AB/GCE). Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Raman tests suggested that AB had a large active surface area, high electron transfer capacity and abundant surface defects. Scanning electron microscopy (SEM) characterization indicated that the AB was composed of a highly porous structure. The fabricated AB/GCE exhibited a remarkable signal enhancement effect toward the oxidation of ractopamine compared to the bare GCE and the graphite modified GCE (graphite/GCE). The oxidation current of ractopamine was recorded using differential pulse voltammetry (DPV) and the optimum experimental conditions were also investigated. Based on the strong signal enhancement effect of AB, a simple, sensitive and rapid electrochemical method was developed for the detection of toxic RAC. The linear range was from 1 μg L⁻¹ to 2 mg L⁻¹ and the detection limit (S/N = 3) was as low as 0.5 μg L⁻¹ (1.6 nM). Finally, the method was successfully applied in the detection of ractopamine in pork samples, and the recovery was in the range from 93.0–106.3%.