Highly Sensitive Assay Of β2Agonists Using Gold Nanoparticles

In recent years, food safety problems caused by p2agonists have drawn a lot of attentions. Hence, many methods have been developed to selectively detect P2agonists. Unfortunately, all these approaches rely on expensive apparatus, time-consuming pre-concentration and purification process. In this paper,β2agonists were selectively detected based on the surface plasma resonance of AuNPs and electrochemical method, which possess advantages including time-saving, low-cost, high sensitivity and application in practical detection. The work was proposed as follows:(1)The ractopamine and melamine were first used to form the chemical stabilized nanochain structure of gold nanoparticles (AuNPs) with a convenient and environmental method. A new longitudinal surface plasma resonance, which could be adjusted from visible to near infrared range, was observed in absorption spectra due to the aggregation of AuNPs. This could be well explained by Finite Different Time Domain algorithm theoretically.(2)As confirmed by Fourier Transform Infrared Spectroscopy, the complex formed by hydrogen-bonding interaction between melamine and ractopamine (or clenbuterol) could effectively promote the aggregation of AuNPs that was useful to develop the sensitivity and selectivity for the detection of Rac and Clb. More importantly, the Rac and Clb could be qualitatively detected by the change of solution’s color. This time-saving and highly selective method will be promising in rapid and selective detection of β2agonists for practical application.(3)The gold nanoparticles were used as an enhanced material for selective detection of ractopamine (Rac) and metaproterenol (Meta) with electrochemical methods. The AuNPs modified glassy carbon electrode (GCE) shows higher electron transfer rate and surface area than the bare one. Meanwhile, the electrochemical behaviors and mechanism of ractopamine and metaproterenol were well explained by PM3calculated method and cyclic voltammetry. Furthermore, this simple and time-saving sensing platform may be extended to the determination of other bio-compounds with electroactive groups.