Key Laboratory of Analysis and Detection for Food Safety (MOE & Fujian Province), Collaborative Innovation Center of Detection Technology for Haixi Food Safety and Products (Fujian Province), State Key Laboratory of Photocatalysis on Energy and Environment, Department of Chemistry, Fuzhou University, Fuzhou 350108, China.
Analyst. 2017 Mar 13;142(6):911-917. doi: 10.1039/c6an02722a.
Developing simple, high-efficiency non-enzyme bioassays is of great importance for modern analytical systems, but remains a significant challenge. One promising route is to utilize highly efficient nanocatalysts with the exposure of active crystal facets. Herein, we for the first time propose a novel colorimetric immunoassay for the ultrasensitive detection of the human prostate-specific antigen (PSA) based on using a unique type of nanolabel - high-index {hk0} faceted platinum concave nanocubes (HIF-Pt-CNCs). The proposed HIF-Pt-CNCs exhibit superior peroxidase-like catalytic activity that is ∼1500- and ∼4-fold higher than that of natural horseradish peroxidase and Pt nanospheres, respectively, and thereby can provide powerful signal amplification by catalyzing the oxidation of peroxidase substrates in the presence of hydrogen peroxide. Using the HIF-Pt-CNC-labelled anti-PSA detection antibody as a signal probe, the immunoassay is carried out in anti-PSA capture antibody-immobilized microplate wells in a sandwich-type detection mode. Under optimal conditions, the developed immunoassay is able to achieve high sensitivity and specificity for PSA detection in a linear range of 20-2000 pg mL and with an ultralow detection limit of 0.8 pg mL, which is much lower than that of conventional enzyme-linked immunosorbent assay (ELISA). Moreover, the method is validated for the analysis of 10 PSA clinical serum specimens, and the results agree very well with those obtained by using a commercialized ELISA kit. Therefore, this new, facile and efficient immunoassay is a promising technique with potential applications in medical science research and clinical diagnosis.
开发简单、高效的非酶生物分析对于现代分析系统非常重要，但仍然是一个重大挑战。一种很有前途的方法是利用暴露在活性晶面的高效纳米催化剂。在此，我们首次提出了一种基于新型纳米标签——高指数 {hk0} 面棱状铂凹纳米立方（HIF-Pt-CNC）的用于超灵敏检测人前列腺特异性抗原（PSA）的新型比色免疫分析。所提出的 HIF-Pt-CNC 表现出优异的过氧化物酶样催化活性，分别比天然辣根过氧化物酶和 Pt 纳米球高约 1500 倍和 4 倍，因此可以通过在存在过氧化氢的情况下催化过氧化物酶底物的氧化提供强大的信号放大。使用 HIF-Pt-CNC 标记的抗 PSA 检测抗体作为信号探针，该免疫分析以夹心型检测模式在抗 PSA 捕获抗体固定化微孔板孔中进行。在最佳条件下，开发的免疫分析能够在 20-2000 pg mL 的线性范围内实现高灵敏度和特异性，并且检测限低至 0.8 pg mL，远低于常规酶联免疫吸附测定（ELISA）。此外，该方法经过 10 个 PSA 临床血清标本的分析验证，与使用商业化 ELISA 试剂盒获得的结果非常吻合。因此，这种新的、简便高效的免疫分析是一种很有前途的技术，具有在医学科学研究和临床诊断中的潜在应用。
