Visual Discrimination of Phenolic Group 尾2-Agonists and the Ultrasensitive Identification of Their Oxidation Products by Use of a Tyrosinase-Based Catalytic Reaction

详细信息    查看全文

• 作者：Huayu Xiong ; Chunhui Guo ; Ping Liu ; Wei Xu ; Xiuhua Zhang ; Shengfu Wang
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：May 20, 2014
• 年：2014
• 卷：86
• 期：10
• 页码：4729-4738
• 全文大小：644K
• 年卷期：v.86,no.10(May 20, 2014)
• ISSN：1520-6882

文摘

The fast, visual discrimination of 尾₂-agonist drugs is needed for the on-site screening of various types of 尾₂-agonists in blood and urine samples. We developed a simple, rapid, one-step colorimetric method to detect phenolic 尾₂-agonists by use of a tyrosinase catalytic reaction, which involved the oxidation of the phenol group on the benzene rings of 尾₂-agonists. The enzymatic oxidation products of 尾₂-agonists with phenolic groups exhibited different color transitions based on the different substituent groups on the aromatic ring, whereas 尾₂-agonists with the aniline group or the resorcinol group remained colorless. This visual color discrepancy has been used to intuitively and conveniently differentiate the phenolic group 尾₂-agonists, such as ractopamine, isoxsuprine, ritodrine, and fenoterol. The oxidation products of these compounds have been identified using mass spectrometry, and the possible reaction mechanisms between 尾₂-agonists and tyrosinase have been deduced. The parameters that govern the analytical performance of the reaction product, including the pH of the buffer solution, the concentration of tyrosinase, and the incubation time, have been studied and optimized using ultraviolet鈥搗isible (UV鈥搗is) spectroscopy and electrochemical methods. Under the optimal experimental conditions, the absorbance intensity and electrochemical signal were found to increase proportionally to the concentrations of the phenolic group 尾₂-agonists, which gave a quantitative description of the 尾₂-agonists in solution.