A Fully Integrated CMOS Fluorescence Biochip for DNA and RNA Testing.

Area of Science:

• Biotechnology
• Microfluidics
• Molecular Diagnostics

Background:

• Molecular diagnostics (MDx) requires sensitive and integrated platforms for DNA/RNA analysis.
• Existing biochip technologies face challenges in sensitivity, integration, and thermal cycling capabilities.

Purpose of the Study:

• To design and implement a fully-integrated CMOS fluorescence biochip for advanced DNA/RNA testing.
• To demonstrate the biochip's utility in molecular diagnostics applications, including viral detection.

Main Methods:

• Development of a 32×32 array of biosensing elements on a CMOS chip.
• Integration of unique DNA probe sequences, filters, resistive heaters, and photodetectors in each element.
• Utilizing a photodiode as the optical transducer and a ΣΔ modulator for photocurrent sensing.
• Employing thermal cycling for multiplexed viral detection.

Main Results:

• The biochip features biosensing elements (100µm×100µm) with integrated photodiodes (50µm×50µm).
• Photodetector performance demonstrated a ~116 dB dynamic range (10fA - 10nA) across 25°C - 100°C, near the shot-noise limit.
• Successful 7-plex panel adoption for detecting 6 human upper respiratory viruses.

Conclusions:

• The integrated CMOS fluorescence biochip offers a high-performance solution for molecular diagnostics.
• The demonstrated thermal cycling and multiplexing capabilities support complex MDx assays.
• This technology has significant potential for advancing rapid and accurate disease detection.