The combination of a nanopore with a local field-effect transistor (FET-nanopore), like a nanoribbon, nanotube, or nanowire, in order to sense single molecules translocating through the pore is promising for DNA sequencing at megahertz bandwidths. Previously, it was experimentally determined that the detection mechanism was due to local potential fluctuations that arise when an analyte enters a nanopore and constricts ion flow through it, rather than the theoretically proposed mechanism of direct charge coupling between the DNA and nanowire. However, there has been little discussion on the experimentally observed detection mechanism and its relation to the operation of real devices. We model the intrinsic signal and noise in such an FET-nanopore device and compare the results to the ionic current signal. The physical dimensions of DNA molecules limit the change in gate voltage on the FET to below 40 mV. We discuss the low-frequency flicker noise (<10 kHz), medium-frequency thermal noise (<100 kHz), and high-frequency capacitive noise (>100 kHz) in FET-nanopore devices. At bandwidths dominated by thermal noise, the signal-to-noise ratio in FET-nanopore devices is lower than in the ionic current signal. At high frequencies, where noise due to parasitic capacitances in the amplifier and chip is the dominant source of noise in ionic current measurements, high-transconductance FET-nanopore devices can outperform ionic current measurements.

中文翻译：

---

FET-纳米管器件中的信号和噪声

纳米孔与局部场效应晶体管（FET-纳米孔）（如纳米带，纳米管或纳米线）的组合，以感测单个分子穿过孔的移位，有望在兆赫兹带宽下进行DNA测序。以前，通过实验确定检测机制是由于当分析物进入纳米孔并限制离子流通过它时出现的局部电势波动，而不是理论上提出的DNA与纳米线之间直接电荷偶联的机制。但是，关于实验观察到的检测机制及其与实际设备操作之间关系的讨论很少。我们在这种FET-纳米孔器件中对固有信号和噪声进行建模，并将结果与​​离子电流信号进行比较。DNA分子的物理尺寸将FET上栅极电压的变化限制在40 mV以下。我们讨论了FET纳米器件中的低频闪烁噪声（<10 kHz），中频热噪声（<100 kHz）和高频电容性噪声（> 100 kHz）。在以热噪声为主的带宽下，FET纳米孔器件中的信噪比低于离子电流信号中的信噪比。在高频率下，由于放大器和芯片中的寄生电容引起的噪声是离子电流测量中的主要噪声源，因此，高导通FET纳米孔器件的性能会优于离子电流测量。FET纳米器件中的100 kHz）。在热噪声为主的带宽下，FET纳米孔器件中的信噪比低于离子电流信号中的信噪比。在高频率下，由于放大器和芯片中的寄生电容引起的噪声是离子电流测量中的主要噪声源，因此，高导通FET纳米孔器件的性能会优于离子电流测量。FET纳米器件中的100 kHz）。在热噪声为主的带宽下，FET纳米孔器件中的信噪比低于离子电流信号中的信噪比。在高频率下，由于放大器和芯片中的寄生电容引起的噪声是离子电流测量中的主要噪声源，因此，高导通FET纳米孔器件的性能会优于离子电流测量。