Tumor necrosis factor-alpha (TNF-α) serves as a crucial biomarker in various diseases, necessitating sensitive detection methodologies. This study introduces an innovative approach utilizing an aptamer-functionalized surface plasmon resonance (SPR) substrate together with an ultrasensitive measure, the Goos–Hänchen (GH) shift, to achieve sensitive detection of TNF-α. The developed GH-aptasensing platform has shown a commendable figure-of-merit of 1.5 × 10⁴ μm per RIU, showcasing a maximum detectable lateral position shift of 184.7 ± 1.2 μm, as characterized by the glycerol measurement. Employing aptamers as the recognition unit, the system exhibits remarkable biomolecule detection capabilities, including the experimentally obtained detection limit of 1 aM for the model protein bovine serum albumin (BSA), spanning wide dynamic ranges. Furthermore, the system successfully detects TNF-α, a small cytokine, with an experimental detection limit of 1 fM, comparable to conventional SPR immunoassays. This achievement represents one of the lowest experimentally derived detection limits for cytokines in aptamer-based SPR sensing. Additionally, the application of the GH shift marks a ground breaking advancement in aptamer-based biosensing, holding significant promise for pushing detection limits further, especially for small cytokine targets.

中文翻译：

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基于适体功能化表面等离子共振底物和古斯-汉兴位移的肿瘤坏死因子-α的增强生物传感

肿瘤坏死因子-α (TNF-α) 是多种疾病的重要生物标志物，因此需要灵敏的检测方法。本研究介绍了一种创新方法，利用适配体功能化表面等离子共振 (SPR) 底物和超灵敏测量方法（古斯-汉兴 (GH) 位移）来实现 TNF-α 的灵敏检测。开发的 GH-适体传感平台显示出每个 RIU 1.5 × 10 ⁴ μm的值得称赞的品质因数，通过甘油测量表征，最大可检测横向位置偏移为 184.7 ± 1.2 μm。该系统采用适配体作为识别单元，表现出卓越的生物分子检测能力，包括实验获得的模型蛋白牛血清白蛋白（BSA）检测限为1 aM，动态范围宽。此外，该系统成功检测了小细胞因子 TNF-α，实验检测限为 1 fM，与传统 SPR 免疫分析相当。这一成就代表了基于适体的 SPR 传感中细胞因子的最低实验检测限之一。此外，GH 位移的应用标志着基于适体的生物传感领域的突破性进展，为进一步推动检测极限（尤其是对于小细胞因子靶标）带来了重大希望。