An aptamer based assay for the beta-adrenergic agonist ractopamine based on aggregation of gold nanoparticles in combination with a molecularly imprinted polymer

作者：Wang, Peilong; Su, Xiaoou^*; Shi, Lei; Yuan, Yuwei^*

来源：Microchimica Acta, 2016, 183(11): 2899-2905.

DOI：10.1007/s00604-016-1913-5

• Aptasensor
• Salt-induced aggregation
• Visual test
• Bioassay
• Molecularly imprinted membrane

A sensitive visual aptamer-based assay is presented for the determination of ractopamine (RAC) in animal feed beef. In the absence of RAC, the aptamer binds to gold nanoparticles (AuNPs) and this prevents the AuNPs to undergo salt-induced aggregation which usually is accompanied by a color change from red to blue. If however, RAC is present, it will bind to the aptamer while the AuNPs remain uncoated so that aggregation and a color change will occur due to salt-induced aggregation. This can be monitored by spectrophotometer or even with bare eyes. Under optimal conditions, the aptasensor exhibits a linear range that covers the 10 to 400 ng.mLaEuro3/4(1) RAC concentration range. The limit of detection is as low as 10 ng.mLaEuro3/4(1). In order to further improve selectivity, a RAC-selective molecularly imprinted membrane was prepared and used to pre-extract RAC from complex samples. The combined method (molecularly imprinted membrane and aptasensor) was applied to the determination of RAC in spiked animal feed and beef and gave recoveries that ranged from 72.7 % to 87.3 % for complete feed and from 78.2 % to 86.5 % for beef, respectively.

• 出版日期2016-11
• 单位中国农业科学院农业质量标准与检测技术研究所; 辽宁师范大学; 浙江省农业科学院