Sun Alexander C, Alvarez-Fontecilla Enrique, Venkatesh A G, Aronoff-Spencer Eliah, Hall Drew A
Electrical and Computer Engineering Department, University of California, San Diego, La Jolla, CA 92093 USA.
School of Medicine, University of California, San Diego, La Jolla, CA 92093 USA.
IEEE J Solid-State Circuits. 2018 Jul;53(7):2054-2064. doi: 10.1109/JSSC.2018.2820705. Epub 2018 Apr 27.
High-density biosensor arrays are essential for many cutting-edge biomedical applications including point-of-care vaccination screening to detect multiple highly-contagious diseases. Typical electrochemical biosensing techniques are based on the measurement of sub-pA currents for micron-sized sensors requiring highly-sensitive readout circuits. Such circuits are often too complex to scale down for high-density arrays. In this paper, a high-density 4,096-pixel electrochemical biosensor array in 180 nm CMOS is presented. It uses a coulostatic discharge sensing technique and interdigitated electrode geometry to reduce both the complexity and size of the readout circuitry. Each biopixel contains an interdigitated microelectrode with a 13 aA low-leakage readout circuit directly underneath. Compared to standard planar electrodes, the implemented interdigitated electrodes achieve a maximum amplification factor of 10.5× from redox cycling. The array's sensor density is comparable to state-of-the-art arrays, all without augmenting the sensors with complex post-processing. The detection of anti-Rubella and anti-Mumps antibodies in human serum is demonstrated.
高密度生物传感器阵列对于许多前沿生物医学应用至关重要，包括用于检测多种高传染性疾病的即时护理疫苗接种筛查。典型的电化学生物传感技术基于对微米级传感器亚皮安电流的测量，这需要高灵敏度的读出电路。此类电路往往过于复杂，难以缩小规模用于高密度阵列。本文展示了一种采用180纳米互补金属氧化物半导体（CMOS）工艺的4096像素高密度电化学生物传感器阵列。它采用恒流放电传感技术和叉指电极结构，以降低读出电路的复杂性和尺寸。每个生物像素都包含一个叉指微电极，其正下方是一个具有13阿安低泄漏读出电路。与标准平面电极相比，所采用的叉指电极通过氧化还原循环实现了最大10.5倍的放大倍数。该阵列的传感器密度与最先进的阵列相当，且所有这些均无需通过复杂的后处理来增强传感器性能。本文还展示了对人血清中抗风疹和抗腮腺炎抗体的检测。
