Studies On The Nanomaterials Amplified Molecular Imprinted Sensors For Analysis Of β-agonists

β-agonists could be utilized for promoting growth and decreasing fat deposition in animals. However, they could also affect human health negatively associated with the residues of them in animal products. At present, for β-agonists administrations, the officials have always screening the samples with fast analysis technologies, followed by confirming the suspicious samples with LC-MS/MS or other technologies. The mentioned technologies could result in false positive or negative for fast analysis and may cost a lot of time for LC-MS/MS separately. It will be of great essence to develop fast, accurate and sensitive technologies for analysis of β-agonists.Molecular imprinted sensor could combine the advantages of specific affinity of molecular imprinted polymers(MIP) and the fast analysis of sensors. However, it also has the shortcoming of low sensitivity for small-molecule as β-agonists, because the small molecules could hardly have high signal response in sensors. The nanomaterials could have the effect of amplification on sensors for their high specific surface area and surface reactivity. Based on the above mentioned, the sensors have been prepared on the combination of MIP and nomaterials with different fabricated methods. The conclusions and results of the paper are as followed:(1) The MIP electrochemical sensor was prepared by electro-deposition method with RAC as template, o-phenylendiamine(OPD) as monomer on the reduced graphene oxide(rGO)/Au nanoparticles(AuNPs) fabricated on the glass carbon electrode. When rGO fabricated by drop-coating method and AuNPs by electro-deposition, HAc-NaAc(pH 5.3) as the solvent, the electropolymerization conducted with 10 CV cycles in the potential range 0 to +2.0 V with the ratio of monomer and template as 1:3, the electroelution solvent as PBS(pH=7.0) the prepared sensor could get satisfied results. Based on the optimized conditions, the LOD was 0.0244ng/mL with the recovery higher than 80% in urine samples. This work provides a promising method for enhancing the performance of MIP electrochemical sensors, which was owned to the nanomaterials.(2) The prepared MIP SPR sensor was prepared by directly “grafting to “method with combination the MIP and nanomaterials of rGO and Gold nanopatricles(GNPs). The MIP was sythesized according to precious reports with some changes of cross-linkers and porogen. The results indicated that the nanomaterials of rGO/GNPs and MIPs was dispersed homogeneously with suitable thickness. The MIP SPR sensor could only cost 780 s for analysis of a sample when the running buffer was selected as PBS(pH=7.0), sample solvent as PBS/ acetonitrile(9:1,v/v). The prepared sensor showed high selectivity and sensitivity for β-agonists with LOD of 5ng/mL. Compared with other MIP SPR sensors(LOD 20-50ng/mL), the prepared sensor demonstrated high sensitivity when rGO/GNPs was utilized. We regard this study as a preliminary step for further exploration and application for other compounds.In this study, the prepared sensors have high sensitivity and selectivity for β-agonists were made of nanomaterials and MIP on the bare SPR sensor chip and glass carbon electrode, and also could conduct accurate analysis. The results could be as a reference to other analytes for analysis by utilizing the MIP sensors.