School of Microelectronics, Tianjin Key Laboratory of Imaging and Sensing Microelectronic, Tianjin University, Tianjin 300072, People's Republic of China.
Tianjin Hospital, Tianjin 300299, People's Republic of China.
Nanotechnology. 2023 Aug 14;34(43). doi: 10.1088/1361-6528/aceb6a.
Field-effect transistor (FET) biosensors based on two-dimensional materials have gained extensive attention due to their high sensitivity, label-free detection capability, and fast response. Molybdenum disulfide (MoS), with tunable bandgap, high surface-to-volume ratio, and smooth surface without dangling bonds, is a promising material for FET biosensors. Previous reports have demonstrated the fabrication of MoS-FET biosensors and their high sensitivity detection of proteins. However, most prior research has focused on the realization of MoS-FETs for detecting different kinds of proteins or molecules, while comprehensive analysis of the sensing mechanism and dominant device factors of MoS-FETs in response to proteins is yet to investigate. In this study, we first fabricated MoS-FET biosensor and detected different types of proteins (immunoglobulin G (IgG),-actin, and prostate-specific antigen (PSA)). Secondly, we built the model of the device and analyzed the sensing mechanism of MoS-FETs in response to proteins. Experimental and modeling results showed that the induced doping effect and gating effect caused by the target protein binding to the device surface were the major influential factors. Specifically, the channel doping concentration and gate voltage () offset exhibited monotonic change as the concentration of the protein solution increases. For example, the channel doping concentration increased up to ∼37.9% and theoffset was ∼-1.3 V with 10glIgG. The change was less affected by the device size. We also investigated the effects of proteins with opposite acid-base properties (-actin and PSA) to IgG on the device sensing mechanism.-actin and PSA exhibited behavior opposite to that of IgG. Additionally, we studied the response behavior of MoS-FETs with different dimensions and dielectric materials (channel length, MoSthickness, dielectric layer thickness, dielectric layer material) to proteins. The underlying mechanisms were discussed in details. This study provides valuable guidelines for the design and application of MoS-FET biosensors.
基于二维材料的场效应晶体管（FET）生物传感器由于其高灵敏度、无标记检测能力和快速响应而受到广泛关注。二硫化钼（MoS）具有可调带隙、高表面积与体积比以及无悬空键的光滑表面，是 FET 生物传感器的一种很有前途的材料。先前的报告已经展示了 MoS-FET 生物传感器的制造及其对蛋白质的高灵敏度检测。然而，大多数先前的研究都集中在实现用于检测不同种类的蛋白质或分子的 MoS-FET，而对 MoS-FET 响应蛋白质的传感机制和主要器件因素的综合分析尚未进行研究。在这项研究中，我们首先制造了 MoS-FET 生物传感器并检测了不同类型的蛋白质（免疫球蛋白 G（IgG）、-肌动蛋白和前列腺特异性抗原（PSA））。其次，我们构建了器件模型并分析了 MoS-FET 响应蛋白质的传感机制。实验和建模结果表明，目标蛋白质与器件表面结合引起的掺杂效应和栅极效应是主要影响因素。具体来说，通道掺杂浓度和栅极电压（Vgs）偏移随蛋白质溶液浓度的增加呈单调变化。例如，当 10glIgG 存在时，通道掺杂浓度增加了约 37.9%，Vgs 偏移约为-1.3V。这种变化受器件尺寸的影响较小。我们还研究了具有相反酸碱性质的蛋白质（-肌动蛋白和 PSA）对 IgG 对器件传感机制的影响。-肌动蛋白和 PSA 表现出与 IgG 相反的行为。此外，我们研究了具有不同尺寸和介电材料（沟道长度、MoS 厚度、介电层厚度、介电层材料）的 MoS-FET 对蛋白质的响应行为。详细讨论了潜在的机制。这项研究为 MoS-FET 生物传感器的设计和应用提供了有价值的指导。
