An Ultrasensitive CMOS Magnetic Biosensor Array for Point-of-Care (POC) Microarray Application

Motivation: PoC biosensing requires high sensitivity, high portability, low cost and low power.

Applications: • Medical Diagnosis (epidemic disease control…) • Environmental Monitoring (pollution…)• Bio-warfare (lethal agents detection…)

Background: • Optical microarray bulky and expensive optics.• Existing magnetic sensors external B-field and costly post-processing.

Our Approach: Frequency shift magnetic-based biosensor No magnetic biasing and completely CMOS compatible

An Ideal PoC Sensor

Sensor Mechanism and System Architecture

Mechanism: Frequency Shift of the On-chip LC Oscillator

Sensitivity Improving: Diff. Sensing and On-chip Temp Ctrl σ∆f/f0=0.13ppm

Architecture: Down-Conversion and 8-Cell Array

Sensor SNR Optimization

DAC Tools: HFSS, Maxwell, Matlab / Ephysics / Spectre, UltraSim, Virtuso, Calibre

Sensor Inductor Geometry

Chip Microphotograph and Measurement Results

Summary: 2.95mm x 2.56mm in 130nm CMOS with 165mW

Magnetic Bead Sensing: A single 1μm bead

Actual DNA Sensing: 1n-Molar magnetically labeled DNA

The Most Sensitive CMOS Magnetic Biosensor