A sensitive solid-state electrochemiluminescence sensor for clenbuterol relying on a PtNPs/RuSiNPs/Nafion composite modified glassy carbon electrode

Abstract

In this work, a highly sensitive electrochemiluminescence (ECL) sensor for the detection of clenbuterol (CBT) in pork is reported. The fabrication of the sensor was carried out by modification of a glassy carbon electrode (GCE) with platinum nanoparticles (PtNPs)/silica nanoparticles doped with [Ru(bpy)3]2+ (RuSiNPs)/Nafion composite. The morphology, composition and electrochemical behavior of the PtNPs/RuSiNPs were characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy and electrochemical impedance spectroscopy, respectively. It was found that all the PtNPs are formed on the surface of RuSiNPs and the electron transfer resistance was obviously reduced on the PtNPs/RuSiNPs GCE. Taking the advantage of the Si-O-Si grid of RuSiNPs, the [Ru(bpy)3]2+ luminophore leaching from the modified electrode could largely be prevented, benefiting the ECL signal stability. Moreover, due to the enhanced electron transfer rate and electrocatalytical property of the PtNPs, the sensitivity of the PtNPs/RuSiNPs-based sensor was greatly improved. Under optimized conditions, the ECL peak intensity was linear with the concentration of CBT in the range of 5–100ngmL−1, with a detection limit as low as 0.8ngmL−1. The recoveries of the CBT obtained from spiked pork samples at PtNPs/RuSiNPs/Nafion GCE were between 89.5% and 106.3% and the RSDs were lower than 6.21%. The proposed ECL sensor based on PtNPs/RuSiNPs composite presented good characteristics for CBT determination in terms of rapid, high sensitivity and good stability, promising the applicability of this sensor in real samples.