Platinum-catalyzed hydrogen evolution reaction for sensitive electrochemical immunoassay of tetracycline residues
Platinum-catalyzed hydrogen evolution reaction for sensitive electrochemical immunoassay of tetracycline residues
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DOI：
10.1016/j.jelechem.2013.06.023
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发表时间：
2013-09-01
影响因子：
4.5
通讯作者：
Tang, Dianping
中科院分区：
文献类型：
--
作者：
Que, Xiaohua;Chen, Xian;Tang, Dianping
利用铂催化的析氢反应(HER)，在抗四环素抗体修饰的免疫传感器上建立了一种新的信号放大方法，用于四环素的灵敏电化学检测。为了构建这种HER，首先将铂纳米颗粒沉积到石墨烯纳米片上，然后将合成的铂/石墨烯纳米片(PtGN)用于标记四环素-牛血清白蛋白结合物(TC-BSA)。在竞争性免疫分析模式下，将所得到的免疫传感器浸入含有1.0 mM PtCl42-、0.1M甲酸盐(还原剂)和0.5%吐温80(pH 6.5)的铂显影液中，以促进铂的生长。在含有10 mM HCl和1.0M KCl的酸性介质中，放大的电化学信号主要来自铂催化的HER。分别研究了铂标记的TC-BSA和PtGN标记的TC-BSA在铂增强前后的两种标记方法和分析方法，并利用石墨烯纳米片和铂的生长机理得到了改进的分析特性。利用PtGN标记的TC-BSA，研究了抗原抗体反应的孵育时间和铂的沉积时间对免疫传感器电流的影响。TC-BSA与PtGN的结合力强，重复性好，中位精密度可达9.8%。在3S(空白)水平下，四环素的动态浓度范围为0.05~100 ng/mL，最低检测下限为6 pg/mL。此外，用蜂蜜、牛奶和花生等四环素添加样品进一步验证了方法的有效性，回收率为86-118%。(C)2013爱思唯尔B.V.保留所有权利。
A new signal amplification strategy for sensitive electrochemical determination of tetracycline (TC) was developed by using platinum-catalyzed hydrogen evolution reaction (HER) on an anti-TC antibody-modified immunosensor. To construct such a HER, platinum nanoparticles were initially deposited to graphene nanosheets, and the as-synthesized platinum/graphene nanosheets (PtGN) were then used for the labeling of tetracycline-bovine serum albumin conjugates (TC-BSA). With a competitive immunoassay format, the resulting immunosensor was immersed into a platinum developer solution containing 1.0 mM PtCl42-, 0.1 M formate (reductant) and 0.5% Tween 80 (pH 6.5) to promote the platinum growth. The amplified electrochemical signal mainly derived from the platinum-catalyzed HER in an acidic medium containing 10 mM HCl and 1.0 M KCl. Two labeling methods and assay protocols including Pt-labeled TC-BSA and PtGN-labeled TC-BSA with or without the platinum enhancement were investigated for determination of target TC, respectively, and improved analytical features were obtained with graphene nanosheets and platinum growth mechanism. With PtGN-labeled TC-BSA, the effects of incubation time for antigen-antibody reaction and deposition time of platinum on the currents of the immunosensors were also studied. The strong attachment of TC-BSA to the PtGN resulted in a good repeatability and intermediate precision down to 9.8%. The dynamic concentration range spanned from 0.05 ng/mL to 100 ng/mL tetracycline with a low detection limit of 6 pg/mL at the 3s(blank) level. In addition, the methodology was further validated with tetracycline spiked samples including honey, milk and peanut, and the recoveries were 86-118%. (C) 2013 Elsevier B.V. All rights reserved.