Irregular-shaped platinum nanoparticles as peroxidase mimics for highly efficient colorimetric immunoassay
Irregular-shaped platinum nanoparticles as peroxidase mimics for highly efficient colorimetric immunoassay
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DOI：
10.1016/j.aca.2013.03.034
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发表时间：
2013-05-07
影响因子：
6.2
通讯作者：
Tang, Dianping
中科院分区：
文献类型：
--
作者：
Gao, Zhuangqiang;Xu, Mingdi;Tang, Dianping
基于天然酶标记探针的酶联免疫吸附测定（ELISA）方法已被应用于免疫分析中，但大多数方法存在一些不可避免的局限性（如制备、纯化和储存条件苛刻），不适合常规使用。本文中，我们合成了一类新的不规则形状的铂纳米颗粒（ISPtNP），其平均长度为7.0 nm，沿纵轴沿着的宽度从2.0到5.0 nm变窄，其被用作过氧化物酶样模拟物用于比色免疫测定的发展。与辣根过氧化物酶（HRP）相比，合成的ISPtNP对3，3 '，5，5'-四甲基联苯胺（TMB）的Km值较低（约为0.12 mM），Kcat值较高（约为2.27 × 10（4）s（-1）），具有较强的热稳定性和pH耐受性。首次探讨了ISPtNP对TMB/H_2O_2的催化机理。以ISPtNP和HRP为标记抗体，分别设计并建立了两种用于兔IgG（RIgG）检测的比色免疫分析方法。与HRP形式相比，ISPtNP标记的RIgG获得了2.5 ng mL（-1）与1.0 ng mL（-1）的相似检测限（LOD）。批内和批间变异系数均小于13%。重要的是，基于ISPtNP的检测系统可能适用于小型化芯片实验室设备的大规模生产，并为蛋白质诊断和生物安全开辟了新的机会。(C)2013爱思唯尔有限公司版权所有。
Enzyme-linked immunosorbent assay (ELISA) methods based on natural enzyme-labeled probes have been applied in the immunoassays, but most have some inevitable limitations (e.g. harsh preparation, purification and storage) and are unsuitable for routine use. Herein we synthesized a new class of irregular-shaped platinum nanoparticles (ISPtNP) with a mean length of 7.0 nm and a narrowing width from 2.0 to 5.0 nm along the longitudinal axes, which were utilized as peroxidase-like mimics for the development of colorimetric immunoassays. Compared with bioactive horseradish peroxidase (HRP), the synthesized ISPtNP exhibited a low K-m value (similar to 0.12 mM) and a high K-cat value (similar to 2.27 x 10(4) s(-1)) for 3,3',5,5'-tetramethylbenzidine (TMB) with strong thermal stability and pH tolerance. The catalytic mechanism of the ISPtNP toward TMB/H2O2 was for the first time discussed and deliberated in this work. Based on a sandwich-type assay format, two types of colorimetric immunoassay protocols were designed and developed for the detection of rabbit IgG (RIgG, as a model) by using the synthesized ISPtNP and conventional HRP as the labeling of detection antibodies, respectively. Similar detection limits (LODs) of 2.5 ng mL(-1) vs. 1.0 ng mL(-1) were obtained toward RIgG with the ISPtNP labeling compared to HRP format. Intra- and inter-assay coefficients of variation were less than 13%. Importantly, the ISPtNP-based assay system could be suitable for use in a mass production of miniaturized lab-on-a-chip devices and open new opportunities for protein diagnostics and biosecurity. (C) 2013 Elsevier B.V. All rights reserved.