A CMOS Pixelated Nanocapacitor Biosensor Platform for High-Frequency Impedance Spectroscopy and Imaging
A CMOS Pixelated Nanocapacitor Biosensor Platform for High-Frequency Impedance Spectroscopy and Imaging
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DOI：
10.1109/tbcas.2018.2861558
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发表时间：
2018-12-01
影响因子：
5.1
通讯作者：
Selmi, Luca
中科院分区：
文献类型：
--
作者：
Widdershoven, Frans;Cossettini, Andrea;Selmi, Luca
我们描述了一个完全电子无标签的温度控制的生物传感平台，旨在克服德拜筛选限制在很宽的范围内的电解质盐浓度的实现。它基于90纳米CMOS集成电路的改进版本，具有纳米电容器阵列，读出和A/D转换电路，以及基于现场可编程门阵列（FPGA）的接口板与NIOS II软处理器。我们描述了芯片的加工，安装，微流体，温度控制系统，以及校准和补偿程序，以减少系统误差，这共同构成了一个完整的定量传感器平台。电容谱记录高达70 MHz的显示，并成功地比较预测有限元法（FEM）数值模拟的泊松漂移扩散形式主义。他们证明了芯片的能力，以达到较高的上限频率的操作，从而克服了低频德拜筛选限制在接近生理盐浓度的电解质，并允许检测事件发生的范围以外的双电层。此外，校准的多频测量能够定量记录电容谱，其特征可以揭示分析物的新特性。电极尺寸、电极间间距和阵列尺寸的可缩放性使得这种感测方法具有相当普遍的适用性，即使在非生物背景下（例如，气体传感）。
We describe the realization of a fully electronic label-free temperature-controlled biosensing platform aimed to overcome the Debye screening limit over a wide range of electrolyte salt concentrations. It is based on an improved version of a 90-nm CMOS-integrated circuit featuring a nanocapacitor array, read-out and A/D conversion circuitry, and a field programmable gate array (FPGA)-based interface board with NIOS II soft processor. We describe chip's processing, mounting, microfluidics, temperature control system, as well as the calibration and compensation procedures to reduce systematic errors, which altogether make up a complete quantitative sensor platform. Capacitance spectra recorded up to 70 MHz are shown and successfully compared to predictions by finite element method (FEM) numerical simulations in the Poisson-Drift-Diffusion formalism. They demonstrate the ability of the chip to reach high upper frequency of operation, thus overcoming the low-frequency Debye screening limit at nearly physiological salt concentrations in the electrolyte, and allowing for detection of events occurring beyond the extent of the electrical double layer. Furthermore, calibrated multifrequency measurements enable quantitative recording of capacitance spectra, whose features can reveal new properties of the analytes. The scalability of the electrode dimensions, interelectrode pitch, and size of the array make this sensing approach of quite general applicability, even in a non-bio context (e.g., gas sensing).