NANOMISENE Lab, LR16CRMN01, Centre for Research on Microelectronics and Nanotechnology of Sousse, Technopole of Sousse B.P. 334, Sahloul 4034, Sousse, Tunisia.
University of Sousse, Higher Institute of Applied Sciences and Technology of Sousse, GREENS-ISSAT, Cité Ettafala, Ibn Khaldoun 4003, Sousse, Tunisia.
Sensors (Basel). 2019 Feb 8;19(3):692. doi: 10.3390/s19030692.
Tumor necrosis factor-α (TNF-α) is a biomarker of inflammation that occurs in patients suffering from heart failure (HF). Saliva can be sampled in a non-invasive way, and it is currently gaining importance as matrix alternative to blood in diagnostic and therapy monitoring. This work presents the development of an immunosensor array based on eight screen-printed gold electrodes to detect TNF-α in saliva samples. Two different functionalization strategies of electrodes were compared. In the first, anti-TNF-α antibodies were chemically bonded onto the electrode by functionalization with 4-carboxymethylaniline. The other functionalization procedure involved the binding of antibodies onto polymer-coated magnetic microparticles, which were then deposited onto the electrode by pulsed chronoamperometry. Finally, the chronoamperometry technique was applied to characterize the modified SPEAu. The use of a secondary antibody anti-TNF-α (Ab-TNF-α-HRP) labelled with horseradish peroxidase (HRP, 2 µg·mL) was investigated using tetramethylbenzidine (TMB, pH = 3.75) as electrochemical substrate containing 0.2 mM of H₂O₂. A sandwich-type detection strategy with a secondary antibody anti-TNF-α provided chronoamperometric analyses in 10 s for each sample. Linearity, precision, limit of detection, and selectivity of devices were investigated. Interferences were evaluated by analyzing solutions containing other cytokine produced during the acute stage of inflammation. The immunosensor showed good performance within the clinically relevant concentration range, with a precision of 8%, and a limit of detection of 0.3 pg/mL. Therefore, it may represent a promising tool for monitoring HF in a non-invasive way.
肿瘤坏死因子-α（TNF-α）是心力衰竭（HF）患者炎症的生物标志物。唾液可以通过非侵入性的方式取样，目前作为血液的替代基质，在诊断和治疗监测方面越来越受到重视。本工作提出了一种基于 8 个丝网印刷金电极的免疫传感器阵列，用于检测唾液样品中的 TNF-α。比较了两种不同的电极功能化策略。在第一种策略中，通过用 4-羧甲基苯胺功能化，将抗 TNF-α 抗体化学结合到电极上。另一种功能化过程涉及将抗体结合到聚合物涂覆的磁性微球上，然后通过脉冲计时安培法将其沉积到电极上。最后，应用计时安培法技术对修饰的 SPEAu 进行了表征。研究了使用辣根过氧化物酶（HRP，2 µg·mL）标记的二级抗体抗 TNF-α（Ab-TNF-α-HRP）的情况，电化学底物为含有 0.2 mM H₂O₂的 pH = 3.75 的四甲基联苯胺（TMB）。使用二级抗体抗 TNF-α（Ab-TNF-α-HRP）的三明治型检测策略，每个样品可在 10 s 内进行计时安培分析。研究了器件的线性度、精密度、检测限和选择性。通过分析含有炎症急性期产生的其他细胞因子的溶液来评估干扰。该免疫传感器在临床相关浓度范围内表现出良好的性能，精密度为 8%，检测限为 0.3 pg/mL。因此，它可能成为一种有前途的非侵入性监测 HF 的工具。
