A Multi-Functional CMOS Biosensor Array With On-Chip DEP-Assisted Sensing for Rapid Low-Concentration Analyte...

Area of Science:

• Bioelectronics
• Nanotechnology
• Sensor Technology

Background:

• Current biosensing methods face limitations in speed and sensitivity, especially for low-concentration analytes.
• Actuation-assisted techniques can improve analyte capture and detection efficiency.
• Integrated CMOS platforms offer miniaturization and high-density sensing capabilities.

Purpose of the Study:

• To develop a fully-integrated, multi-functional CMOS biosensor array chip.
• To leverage dielectrophoresis (DEP) for enhanced analyte manipulation and sensing.
• To demonstrate rapid, label-free detection of low-concentration analytes and particle manipulation.

Main Methods:

• Design and fabrication of a 4096-electrode CMOS biosensor chip using a 130-nm BiCMOS process.
• On-chip reconfiguration of working electrodes (WEs) for DEP actuation, electrochemical potentiostat, optical shadow imaging, and impedance sensing.
• Theoretical analysis and finite element method (FEM) simulations for DEP operations.
• Biological assay measurements using E.coli bacteria and microbeads.

Main Results:

• Demonstrated rapid sensing of low-concentration analytes by overcoming diffusion limits using on-chip DEP.
• Achieved simultaneous manipulation and detection of large particles (microbeads) via DEP and photodiode arrays.
• Validated the multi-functional capabilities including electrochemical potentiostat and complex impedance sensing.
• Showcased label-free detection and close-loop manipulation and sensing of particles and droplets.

Conclusions:

• The DEP-assisted multi-functional CMOS biosensor offers significant advantages for rapid, sensitive analyte detection.
• On-chip DEP actuation simplifies design and enhances sensing performance by reducing diffusion limitations.
• The integrated platform enables versatile applications in particle manipulation, droplet sensing, and biological assays.