Song Jian, Dailey Jennifer, Li Hui, Jang Hyun-June, Zhang Pengfei, Wang Jeff Tza-Huei, Everett Allen D, Katz Howard E
Department of Materials Science and Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States.
Department of Materials Science and Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States; Department of Biomedical Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States.
Adv Funct Mater. 2017 May 25;27(20). doi: 10.1002/adfm.201606506. Epub 2017 Mar 23.
A novel organic field effect transistor (OFET) -based biosensor is described for label-free glial fibrillary acidic protein (GFAP) detection. We report the first use of an extended solution gate structure where the sensing area and the organic semiconductor are separated, and a reference electrode is not needed. Different molecular weight polyethylene glycols (PEGs) are mixed into the bio-receptor layer to help extend the Debye screening length. The drain current change was significantly increased with the help of higher molecular weight PEGs, as they are known to reduce the dielectric constant. We also investigated the sensing performance under different gate voltage (V). The sensitivity increased after we decreased V from -5 V to -2 V, because the lower V is much closer to the OFET threshold voltage and the influence of attached negatively charged proteins become more apparent. Finally, the selectivity experiments toward different interferents were performed. The stability and selectivity are promising for clinical applications.
本文描述了一种基于新型有机场效应晶体管（OFET）的生物传感器，用于无标记检测胶质纤维酸性蛋白（GFAP）。我们首次报道了一种扩展的溶液栅结构的应用，其中传感区域与有机半导体分离，且无需参考电极。将不同分子量的聚乙二醇（PEG）混入生物受体层，以帮助延长德拜屏蔽长度。借助较高分子量的PEG，漏极电流变化显著增加，因为已知它们会降低介电常数。我们还研究了不同栅极电压（V）下的传感性能。当我们将V从-5 V降至-2 V后，灵敏度提高，因为较低的V更接近OFET阈值电压，且附着的带负电蛋白质的影响变得更加明显。最后，对不同干扰物进行了选择性实验。该生物传感器的稳定性和选择性在临床应用方面前景广阔。
