Department of Mechanical Engineering, Columbia University, New York, NY, 10027, USA; Department of Mechanical Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, 150001, China.
Department of Mechanical Engineering, Columbia University, New York, NY, 10027, USA.
Talanta. 2022 Dec 1;250:123697. doi: 10.1016/j.talanta.2022.123697. Epub 2022 Jun 20.
We present an approach to enable the sensitive and specific detection of biomarkers in undiluted tears in the eye using an aptamer-based graphene affinity nanosensor. The nanosensor is a graphene field-effect transistor, in which a nucleic acid aptamer and a biomolecule-permeable polyethylene glycol (PEG) nanolayer are immobilized on the graphene surface. The aptamer is capable of specifically recognize the target biomarker and induce a change in the carrier concentration of the graphene, which is measured to determine the biomarker concentration. The PEG nanolayer minimizes nonspecific adsorption of background molecules in the sample that would otherwise interfere with the biomarker detection. Experimental results show that tumor necrosis factor alpha (TNF-alpha), an inflammatory cytokine, can be sensitively and specifically detected in undiluted artificial tears with a limit of detection of 0.34 pM. This ability to detect and measure biomarkers in undiluted physiological fluids allows the nanosensor to be potentially used in applications where sample dilutions are not practical, such as wearable measurements of tear-borne biomarkers in the eye.
我们提出了一种使用基于适配体的石墨烯亲和纳米传感器在未经稀释的眼内泪液中灵敏且特异性地检测生物标志物的方法。该纳米传感器是一种石墨烯场效应晶体管，其中核酸适配体和生物分子可渗透的聚乙二醇（PEG）纳米层固定在石墨烯表面。适配体能够特异性地识别目标生物标志物，并诱导石墨烯载流子浓度发生变化，通过测量该变化来确定生物标志物的浓度。PEG 纳米层最大限度地减少了样品中背景分子的非特异性吸附，否则这些背景分子会干扰生物标志物的检测。实验结果表明，炎症细胞因子肿瘤坏死因子-α（TNF-α）可以在未经稀释的人工泪液中灵敏且特异性地检测到，检测限为 0.34 pM。这种在未经稀释的生理液中检测和测量生物标志物的能力使纳米传感器有可能用于无法进行样品稀释的应用中，例如在眼部测量泪液中携带的生物标志物的可穿戴设备。
