20.5 A Sub-pA ΔΣ Current Amplifier for Single-Molecule Nanosensors
20.5 A Sub-pA ΔΣ Current Amplifier for Single-Molecule Nanosensors
复制标题
适用于单分子纳米传感器的 20.5 A 亚 pA ΔΣ 电流放大器
DOI：
--
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
M. Tartagni
中科院分区：
文献类型：
--
作者：
M. Bennati;F. Thei;M. Rossi;M. Crescentini;Gennaro D'Avino;A. Baschirotto;M. Tartagni
自电子传感器出现以来，电流读出一直是已知的技术，并且广泛用于例如辐射检测器、阻抗谱和机械传感器中。最近，在即将到来的纳米传感器时代，电流检测出现了新的挑战。纳米线，碳纳米管和纳米孔是新兴的设备，已被证明是有效的传感超低浓度的目标分子[1]。对于这些器件，电流检测变得具有挑战性，因为输出由kHz频带中的pA范围或更小范围的信号组成。为了测量这些值，需要非常低噪声的前端放大器，例如[2]中的放大器。它在1kHz时的本底噪声低至20fArms，专为电生理学实验而设计，例如膜片钳技术，其中需要从细胞膜记录单离子通道。然而，该仪器体积庞大，需要一个冷却的云台来提高性能。[3]中报告了一种集成解决方案，提供四电流输入20 b模数转换器。然而，它的测量等效输入噪声在1kHz时超过700fArms。
Current readout has been a known technique since the inception of electronic sensors and is widely used, for example, in radiation detectors, impedance spectroscopy, and mechanical sensors. Recently, new challenges have emerged for current sensing in the upcoming era of nanosensors. Nanowires, carbon nanotubes and nanopores are emerging devices that have been proven to be effective in sensing ultra-low concentrations of target molecules [1]. For those devices, current sensing becomes challenging since outputs consist of signals in the pA range or less, in the kHz band. To measure these values, very low-noise front-end amplifiers are needed such as the one in [2]. It achieves a noise floor as low as 20fArms at 1kHz and it is designed for electrophysiology experiments, such as in patch clamp techniques, where single-ion channel recordings from cell membranes are required. However, the instrument is bulky and needs a cooled headstage to boost performance. An integrated solution offering quad current-input 20b analog-to-digital converters is reported in [3]. However, its measured equivalent input noise is above 700fArms at 1kHz.