Department of Chemistry and Institute of Materials Science, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, USA.
Anal Chem. 2010 Apr 15;82(8):3118-23. doi: 10.1021/ac902802b.
Squamous cell carcinomas of head and neck (HNSCC) are associated with immune, inflammatory, and angiogenic responses involving interleukin-6 (IL-6). This article reports an ultrasensitive electrochemical immunosensor for human IL-6 and proof-of-concept studies of IL-6 detection in HNSCC cells. Single wall carbon nanotube (SWNT) forests with attached capture antibodies (Ab(1)) for IL-6 were used in an electrochemical sandwich immunoassay protocol using enzyme label horseradish peroxidase (HRP) to measure very low (<or=30 pg mL(-1)) and elevated levels of IL-6. Two levels of multienzyme labeling were used to measure a broad concentration range of IL-6 in a representative panel of HNSCC cells. Secondary antibodies (Ab(2)) attached to carboxylated multiwall carbon nanotubes with 106 HRP labels per 100 nm gave the highest sensitivity of 19.3 nA mL (pg IL-6)(-1) cm(-2) and the best detection limit (DL) of 0.5 pg mL(-1) (25 fM) for IL-6 in 10 microL of calf serum. For more concentrated samples, biotinylated Ab(2) bound to streptavidin-HRP to provide 14-16 labels per antigen was used. These immunosensors accurately measured secreted IL-6 in a wide range of HNSCC cells demonstrated by excellent correlations with standard enzyme-linked immunosorbent assays (ELISA), suggesting that SWNT immunosensors combined with multilabel detection have excellent promise for detecting IL-6 in research and clinical applications.
头颈部鳞状细胞癌（HNSCC）与涉及白细胞介素-6（IL-6）的免疫、炎症和血管生成反应有关。本文报道了一种用于人白细胞介素-6 的超灵敏电化学免疫传感器，并对 HNSCC 细胞中白细胞介素-6 的检测进行了概念验证研究。用于电化学三明治免疫测定方案的单壁碳纳米管（SWNT）森林附着有用于白细胞介素-6 的捕获抗体（Ab(1)），使用酶标记辣根过氧化物酶（HRP）来测量非常低（<或=30 pg mL(-1)）和升高的白细胞介素-6 水平。使用两种多酶标记水平来测量代表性 HNSCC 细胞中的白细胞介素-6 的广泛浓度范围。附着有 106 HRP 标签的羧基化多壁碳纳米管的二级抗体（Ab(2)）给出了最高的灵敏度 19.3 nA mL (pg IL-6)(-1) cm(-2)，以及 IL-6 在 10 μL 小牛血清中的最佳检测限（DL）为 0.5 pg mL(-1)（25 fM）。对于更浓缩的样品，使用与 HRP 结合的生物素化 Ab(2) 结合链霉亲和素来提供每个抗原 14-16 个标签。这些免疫传感器通过与标准酶联免疫吸附测定（ELISA）的出色相关性，准确测量了广泛范围的 HNSCC 细胞中分泌的白细胞介素-6，这表明 SWNT 免疫传感器与多标记检测相结合在研究和临床应用中具有检测白细胞介素-6 的巨大潜力。
