School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi City, Ishikawa 923-1292, Japan.
Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Patumwan, Bangkok 10330, Thailand.
Sensors (Basel). 2018 Feb 3;18(2):444. doi: 10.3390/s18020444.
In this work, a simple electrochemical immunoassay based on platinum nanoparticles (PtNPs) using open circuit potential (OCP) detection was developed. The detection of human chorionic gonadotropin hormone (hCG) as a model analyte, was demonstrated by direct electrical detection of PtNPs in hydrazine solution using OCP measurement without any application of either potential or current to the system. Disposable screen-printed carbon electrodes (SPCEs) were utilized for the development of our immunosensor, which required a sample volume as small as 2 μL. After preparation of a sandwich-type immunosystem, hydrazine solution was dropped on the electrode's surface, which was followed immediately by electrical detection using OCP. The change of the OCP signal originated from electrocatalytic oxidation of the hydrazine on PtNPs. Under the optimal conditions of a pH of 6.0 and a hydrazine concentration of 1 mM, a detection limit of 0.28 ng mL and a linearity of 0-10 ng mL were obtained. The PtNP-based OCP method is a simpler electrochemical detection procedure than those obtained from other electrochemical methods and has an acceptable sensitivity and reproducibility. The simplicity of the detection procedure and the cost-effectiveness of the disposable SPCE illustrate the attractive benefits of this sensor. Moreover, it could be applied to a simplified and miniaturized diagnostic system with minimal user manipulation.
在这项工作中，开发了一种基于铂纳米粒子（PtNPs）的简单电化学免疫分析方法，采用开路电位（OCP）检测。通过使用 OCP 测量，在没有对系统施加任何电位或电流的情况下，直接在肼溶液中检测 PtNPs，实现了对人绒毛膜促性腺激素（hCG）作为模型分析物的直接电检测。采用一次性丝网印刷碳电极（SPCE）开发了我们的免疫传感器，该传感器的样品体积小至 2μL。在制备三明治型免疫体系后，将肼溶液滴在电极表面，然后立即使用 OCP 进行电检测。OCP 信号的变化源于 PtNPs 上肼的电催化氧化。在 pH 值为 6.0 和肼浓度为 1mM 的最佳条件下，检测限为 0.28ngmL，线性范围为 0-10ngmL。基于 PtNP 的 OCP 方法比其他电化学方法获得的检测程序更简单，具有可接受的灵敏度和重现性。检测程序的简单性和一次性 SPCE 的成本效益说明了这种传感器的吸引力。此外，它可以应用于简化和小型化的诊断系统，用户操作最少。
