School of Applied Chemistry and Biological Technology, Shenzhen Polytechnic, Shenzhen, 518055, China.
Anal Sci. 2021 Dec 10;37(12):1701-1706. doi: 10.2116/analsci.21P113. Epub 2021 May 28.
As a gram-positive foodborne pathogen, Listeria monocytogenes (LM) can cause many serious diseases to the human health coupled with high mortality rates; thus, constructing an effective method to detect LM is of great significance. Herein, a novel sandwich-type electrochemical immunosensor is proposed for LM by introducing 3,4,9,10-perylene tetracarboxylic acid/graphene ribbons (PTCA/GNR) nanohybrids as a sensing platform and ferrocene/gold nanoparticles (Fc/Au NPs) as a signal amplifier. The high conductivity and large surface area of GNR can increase the immobilizing amount of the primary antibody (PAb) and enhance the electron transport rate, while Au NPs can carry secondary antibodies (SAb) and Fc derivative (Fc-SH) to form a SAb-Au NPs-Fc signal amplifier. Through using Fc molecules as a signal probe, its peak current can appear and increase varied from the LM concentrations; hence, a highly sensitive sandwich-type immunosensor was constructed wide linear range from 10 to 2 × 10-CFU mL and low limit of detection of low to 6 CFU mL. Furthermore, the specificity of the immunosensor was also studied and a satisfactory result was obtained.
作为一种革兰氏阳性食源性病原体，单增李斯特菌（LM）可导致人类健康出现多种严重疾病，并伴有高死亡率；因此，构建一种有效的 LM 检测方法具有重要意义。本研究引入 3,4,9,10-苝四羧酸/石墨烯纳米带（PTCA/GNR）纳米杂化物作为传感平台，利用二茂铁/金纳米颗粒（Fc/Au NPs）作为信号放大器，提出了一种用于 LM 的新型三明治型电化学免疫传感器。GNR 的高导电性和大表面积可以增加一级抗体（PAb）的固定量并增强电子传输速率，而 Au NPs 可以携带二级抗体（SAb）和 Fc 衍生物（Fc-SH）以形成 SAb-Au NPs-Fc 信号放大器。通过使用 Fc 分子作为信号探针，其峰电流会根据 LM 浓度的不同而出现和增加；因此，构建了一种具有高灵敏度的三明治型免疫传感器，线性范围从 10 到 2×10-CFU mL，检测限低至 6 CFU mL。此外，还研究了免疫传感器的特异性，得到了令人满意的结果。
