A high sensitivity electrochemical sensor based on a dual-template molecularly imprinted polymer for simultaneous determination of clenbuterol hydrochloride and ractopamine

Abstract

A nitrogen-doped Fe-MOF shows a high specific surface area and excellent electrical conductivity after high temperature carbonization. A novel electrochemical sensor based on a N@Fe-MOF@C loaded dual-template molecularly imprinted polymer (DTMIP) modified glassy carbon electrode (GCE) was proposed for the rapid and ultra-sensitive simultaneous detection of clenbuterol hydrochloride (CLB) and ractopamine (RAC). N@Fe-MOF@C combined with a MIP significantly enhanced the electrical signal. Cyclic voltammetry (CV) was used to detect CLB and RAC. The electrochemical polymerization was conducted with O-phenylenediamine as the functional monomer and CLB and RAC as template molecules. The factors affecting the sensor response were optimized. Under the optimal experimental conditions, the CV current response showed a linear range of 10⁻¹²–8 × 10⁻⁹ M for both CLB and RAC, and the detection limit (LOD) for both CLB and RAC was 3.03 × 10⁻¹³ M (S/N = 3). This electrochemical sensing system has high sensitivity, selectivity, excellent reproducibility, repeatability and stability. The recoveries of the actual samples (97.4%–101.2%) and reasonable relative standard deviations (RSDs) (1.06%–3.17%) indicate the practicability of the sensor system. The system has high application value in the rapid detection of CLB and RAC in clenbuterol hydrochloride tablets, human urine and raw pork.