Nanobioelectronics & Biosensors Group, Institut Catala de Nanociencia i Nanotecnologia (ICN2), Edifici ICN2, Campus UAB, Bellaterra (Barcelona) 08193, Spain.
Nanobioelectronics & Biosensors Group, Institut Catala de Nanociencia i Nanotecnologia (ICN2), Edifici ICN2, Campus UAB, Bellaterra (Barcelona) 08193, Spain; Autonomous University of Barcelona, UAB Campus, 08193 Bellaterra, Spain.
Biosens Bioelectron. 2015 May 15;67:53-8. doi: 10.1016/j.bios.2014.05.066. Epub 2014 Jun 10.
A new gold nanoparticle (AuNP) based detection strategy using Electrochemical Impedance Spectroscopy (EIS) through hydrogen evolution reaction (HER) is proposed. This EIS-HER method is used as an alternative to the conventional EIS based on Fe(CN)6 or Ru(NH3)6 indicators. The proposed method is based on the HER induced by AuNPs. EIS measurements for different amounts of AuNP are registered and the charge transfer resistance (Rct) was found to correlate and be useful for their quantification. Moreover the effect of AuNP size on electrical properties of AuNPs for HER using this sensitive technique has been investigated. Different EIS-HER signals generated in the presence of AuNPs of different sizes (2, 5, 10, 15, 20, and 50 nm) are observed, being the corresponding phenomena extendible to other nanoparticles and related catalytic reactions. This EIS-HER sensing technology is applied to a magneto-immunosandwich assay for the detection of a model protein (IgG) achieving improvements of the analytical performance in terms of a wide linear range (2-500 ng mL(-1)) with a good limit of detection (LOD) of 0.31 ng mL(-1) and high sensitivity. Moreover, with this methodology a reduction of one order of magnitude in the LOD for IgG detection, compared with a chroamperometric technique normally used was achieved.
提出了一种新的基于金纳米粒子（AuNP）的电化学阻抗谱（EIS）通过析氢反应（HER）检测策略。这种基于 HER 的 EIS 方法替代了传统的基于 Fe(CN)6或 Ru(NH3)6指示剂的 EIS。该方法基于 AuNPs 诱导的 HER。记录了不同量 AuNP 的 EIS 测量值，并发现电荷转移电阻（Rct）与之相关且可用于定量。此外，还研究了使用这种灵敏技术，AuNP 大小对 HER 中 AuNP 电性能的影响。观察到不同尺寸（2、5、10、15、20 和 50nm）的 AuNP 存在时产生的不同 EIS-HER 信号，这些现象可扩展到其他纳米粒子和相关的催化反应。该 EIS-HER 传感技术应用于磁免疫夹心测定法检测模型蛋白（IgG），实现了分析性能的改善，具有较宽的线性范围（2-500ng mL(-1))和良好的检测限（LOD）为 0.31ng mL(-1)，灵敏度高。此外，与通常使用的电流安培技术相比，该方法可将 IgG 检测的 LOD 降低一个数量级。
