A Wireless Battery-Free Probe-Free Disposable Electrical-Digital-PCR Chip

Area of Science:

• Molecular Diagnostics
• Biotechnology
• Electrical Engineering

Background:

• Polymerase chain reaction (PCR) is vital for molecular diagnostics but faces challenges in miniaturization, cost, and detection speed/precision, especially during epidemics like COVID-19.
• Conventional fluorescence-PCR and DNA-Probe-PCR methods are hindered by expensive optical instruments, limited detection capabilities, and complex, costly pre-labeling procedures.

Purpose of the Study:

• To develop a probe-free electrical-digital-PCR (EdPCR) chip using impedance detection to overcome limitations of current PCR technologies.
• To enable portable, disposable, and cost-efficient PCR equipment for widespread diagnostic applications.
• To improve the accuracy and reduce the error rate in PCR detection.

Main Methods:

• A novel sensor-on-circuit structure integrated into a single CMOS chip to replace bulky optical instruments.
• Implementation of a harmonic-voting algorithm to mitigate pixel error rate (PER) in impedance-based detection.
• Fabrication using a 55nm CMOS process and validation through in-vitro PCR experiments on diverse samples.

Main Results:

• The developed EdPCR chip features the highest reported pixel density of 1111 pixels/mm².
• The harmonic-voting method successfully reduced the measured PER by 35%, achieving an average PER of 12.2%.
• The system demonstrates potential for portable and disposable PCR applications.

Conclusions:

• The probe-free EdPCR chip represents a significant advancement in molecular diagnostics, offering a cost-effective and portable alternative to conventional PCR systems.
• The integrated sensor-on-circuit design and harmonic-voting method enhance detection precision and reduce hardware costs.
• This technology has broad implications for epidemic surveillance, medical diagnosis, and point-of-care testing.