An ultrasensitive sensor based on polyoxometalate and zirconium dioxide nanocomposites hybrids material for simultaneous detection of toxic clenbuterol and ractopamine

A new electrochemical sensor based on isopolyacid anions (NH 4 ) 5 PV 8 Mo 4 O 40 (NPVMo) and transition metal zirconium dioxide (ZrO 2 ) nanocomposites was prepared in double signal amplification for the simultaneous detection of clenbuterol (CLB) and ractopamine (RAC). This is the first time that ZrO 2 was used as POM carrier to prepare electrochemical sensor. Scanning electron microscopic (SEM), nitrogen adsorption/desorption isotherms and X-ray diffraction (XRD) test showed that the synthesized ZrO 2 nanoparticles have a needlelike nanostructure and a larger surface area. The electrochemical measurements such as cyclic voltammetry (CV), amperometric and differential pulse voltammetry (DPV) indicated that the NPVMo/ZrO 2 /GCE exhibited much high stability, fast response, good conductivity and electrocatalytic actives, which enhanced peak current and negatively shifted the oxidation potentials of CLB and RAC. Due to the synergistic action between NPVMo and ZrO 2 nanoparticles, DPV results showed that the oxidation of CLB and RAC on NPVMo/ZrO 2 /GCE could be detected selectively and sensitively with low limits of detection, 5.03 × 10 −9 mol L −1 for CLB and 9.3 × 10 −7 mol L −1 for RAC, and a wide range for calibration curves of CLB and RAC from 0.1 to 1000 μM and 3.0 to 50 μM, respectively. In addition, the proposed sensor was applied to detect content of CLB and RAC in pork sample, and the recovery was over the range from 94.4 to 102.3%.