Costa Tiago, Cardoso Filipe A, Germano Jose, Freitas Paulo P, Piedade Moises S
IEEE Trans Biomed Circuits Syst. 2017 Oct;11(5):988-1000. doi: 10.1109/TBCAS.2017.2743685. Epub 2017 Sep 14.
The development of giant magnetoresistive (GMR) sensors has demonstrated significant advantages in nanomedicine, particularly for ultrasensitive point-of-care diagnostics. To this end, the detection system is required to be compact, portable, and low power consuming at the same time that a maximum signal to noise ratio is maintained. This paper reports a CMOS front-end with integrated magnetoresistive sensors for biomolecular recognition detection applications. Based on the characterization of the GMR sensor's signal and noise, CMOS building blocks (i.e., current source, multiplexers, and preamplifier) were designed targeting a negligible noise when compared with the GMR sensor's noise and a low power consumption. The CMOS front-end was fabricated using AMS [Formula: see text] technology and the magnetoresistive sensors were post-fabricated on top of the CMOS chip with high yield ( [Formula: see text]). Due to its low circuit noise (16 [Formula: see text]) and overall equivalent magnetic noise ([Formula: see text]), the full system was able to detect 250 nm magnetic nanoparticles with a circuit imposed signal-to-noise ratio degradation of only -1.4 dB. Furthermore, the low power consumption (6.5 mW) and small dimensions ([Formula: see text] ) of the presented solution guarantees the portability of the detection system allowing its usage at the point-of-care.
巨磁阻（GMR）传感器的发展已在纳米医学中展现出显著优势，特别是在超灵敏即时诊断方面。为此，检测系统需要在保持最大信噪比的同时，具备紧凑、便携且低功耗的特点。本文报道了一种用于生物分子识别检测应用的集成磁阻传感器的CMOS前端。基于GMR传感器信号与噪声的特性，设计了CMOS组件（即电流源、多路复用器和前置放大器），使其与GMR传感器的噪声相比噪声可忽略不计且功耗较低。该CMOS前端采用AMS [公式：见原文] 技术制造，磁阻传感器在CMOS芯片顶部进行后加工，成品率很高（ [公式：见原文]）。由于其低电路噪声（16 [公式：见原文]）和整体等效磁噪声（[公式：见原文]），整个系统能够检测250纳米的磁性纳米颗粒，电路导致的信噪比下降仅为 -1.4分贝。此外，所提出方案的低功耗（6.5毫瓦）和小尺寸（[公式：见原文]）保证了检测系统的便携性，使其能够在即时诊断中使用。
