Aptamer based ultrasensitive determination of the β-adrenergic agonist ractopamine using PicoGreen as a fluorescent DNA probe

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• 作者：Chao Zhu ; Guilan Zhang ; Yafei Huang ; Jiao Yan ; Ailiang Chen
• 关键词：Aptamer ; Ractopamine ; PicoGreen ; Swine urine ; dsDNA ; DNA probe ; Fluorescence assay
• 刊名：Microchimica Acta
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：184
• 期：2
• 页码：439-444
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Nanochemistry; Nanotechnology; Characterization and Evaluation of Materials; Analytical Chemistry; Microengineering;
• 出版者：Springer Vienna
• ISSN：1436-5073
• 卷排序：184

文摘

The authors describe an aptamer based assay for determination of ractopamine (RAC) by using PicoGreen (PG) as a fluorescent probe specific for dsDNA. In the absence of RAC, the aptamer forms a duplex structure with a complementary sequence that results in enhanced PG fluorescence. Upon binding to RAC, the aptamer undergoes a structural switch. This reduces the number of DNA duplexes formed and causes a reduction of fluorescence intensity of PG as measured at excitation/emission wavelengths of 480/520 nm. Under optimized conditions, the dynamic calibration plot covers the 50 pM to 50 μM concentration range, with a 50 pM detection limit. This meets the safety supervision regulations of the European Commission in terms of residue limits of RAC in food. The method displays high selectivity over other β-adrenergic agonists including clenbuterol, dopamine and salbutamol. The assay was successfully applied to samples of swine urine at spiking levels of 7.4 nM, 22.2 nM and 37 nM. Average recoveries ranged from 95 to 110%, with an RSD of <1.5%. The method is expected to represent a promising tool for simple, rapid and sensitive on-site detection of RAC in animal products.