Magnetoresistive biosensors with on-chip pulsed excitation and magnetic correlated double sampling.
Kyunglok KimDrew A HallChengyang YaoJung-Rok LeeChin Chun OoiDaniel J B BechsteinYue GuoShan X WangPublished in: Scientific reports (2018)
Giant magnetoresistive (GMR) sensors have been shown to be among the most sensitive biosensors reported. While high-density and scalable sensor arrays are desirable for achieving multiplex detection, scalability remains challenging because of long data acquisition time using conventional readout methods. In this paper, we present a scalable magnetoresistive biosensor array with an on-chip magnetic field generator and a high-speed data acquisition method. The on-chip field generators enable magnetic correlated double sampling (MCDS) and global chopper stabilization to suppress 1/f noise and offset. A measurement with the proposed system takes only 20 ms, approximately 50× faster than conventional frequency domain analysis. A corresponding time domain temperature correction technique is also presented and shown to be able to remove temperature dependence from the measured signal without extra measurements or reference sensors. Measurements demonstrate detection of magnetic nanoparticles (MNPs) at a signal level as low as 6.92 ppm. The small form factor enables the proposed platform to be portable as well as having high sensitivity and rapid readout, desirable features for next generation diagnostic systems, especially in point-of-care (POC) settings.
Keyphrases
- high density
- high throughput
- label free
- high speed
- loop mediated isothermal amplification
- magnetic nanoparticles
- real time pcr
- circulating tumor cells
- low cost
- electronic health record
- sensitive detection
- atomic force microscopy
- molecularly imprinted
- big data
- multiple sclerosis
- single cell
- mass spectrometry
- high resolution
- gold nanoparticles
- data analysis
- machine learning
- quantum dots