BIOS Lab-on-a-Chip Group, MESA+ Institute for Nanotechnology, Max Planck Center for Complex Fluid Dynamics, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
Device Modelling Group, School of Engineering, University of Glasgow, Glasgow G12 8LT, UK.
Sensors (Basel). 2022 Aug 2;22(15):5783. doi: 10.3390/s22155783.
Label-free field-effect transistor-based immunosensors are promising candidates for proteomics and peptidomics-based diagnostics and therapeutics due to their high multiplexing capability, fast response time, and ability to increase the sensor sensitivity due to the short length of peptides. In this work, planar junctionless field-effect transistor sensors (FETs) were fabricated and characterized for pH sensing. The device with SiO gate oxide has shown voltage sensitivity of 41.8 ± 1.4, 39.9 ± 1.4, 39.0 ± 1.1, and 37.6 ± 1.0 mV/pH for constant drain currents of 5, 10, 20, and 50 nA, respectively, with a drain to source voltage of 0.05 V. The drift analysis shows a stability over time of -18 nA/h (pH 7.75), -3.5 nA/h (pH 6.84), -0.5 nA/h (pH 4.91), 0.5 nA/h (pH 3.43), corresponding to a pH drift of -0.45, -0.09, -0.01, and 0.01 per h. Theoretical modeling and simulation resulted in a mean value of the surface states of 3.8 × 10/cm with a standard deviation of 3.6 × 10/cm. We have experimentally verified the number of surface sites due to APTES, peptide, and protein immobilization, which is in line with the theoretical calculations for FETs to be used for detecting peptide-protein interactions for future applications.
基于无标记场效应晶体管的免疫传感器由于其高多重性、快速响应时间以及由于肽的短长度而能够提高传感器灵敏度的能力，是蛋白质组学和肽组学诊断和治疗的有前途的候选者。在这项工作中，平面结型场效应晶体管传感器 (FET) 被制造和表征用于 pH 感测。具有 SiO 栅极氧化物的器件显示出 41.8 ± 1.4、39.9 ± 1.4、39.0 ± 1.1 和 37.6 ± 1.0 mV/pH 的电压灵敏度，对于恒定的漏极电流分别为 5、10、20 和 50 nA，漏源电压为 0.05 V。漂移分析显示在 pH 7.75 时的稳定性为-18 nA/h，在 pH 6.84 时为-3.5 nA/h，在 pH 4.91 时为-0.5 nA/h，在 pH 3.43 时为 0.5 nA/h，对应于每小时-0.45、-0.09、-0.01 和 0.01 的 pH 漂移。理论建模和模拟导致表面态的平均值为 3.8 × 10/cm，标准偏差为 3.6 × 10/cm。我们已经通过 APTES、肽和蛋白质固定化实验验证了表面位点的数量，这与 FET 用于检测肽-蛋白质相互作用的理论计算相符，为未来的应用提供了依据。
