A third-order mode high frequency biosensor with atomic resolution

Area of Science:

• Materials Science
• Biosensing Technology
• Nanotechnology

Background:

• Surface Acoustic Wave (SAW) biosensors offer high sensitivity for molecular detection.
• Existing biosensors face limitations in resolution and quantitative analysis of biological samples.
• Atomic resolution detection is crucial for understanding molecular interactions and disease mechanisms.

Purpose of the Study:

• To develop an atomic resolution, ultra-high sensitivity SAW biosensor.
• To achieve precise detection of DNA sequences and living cells.
• To explore the potential for high-precision medical diagnostics.

Main Methods:

• Fabrication of interdigitated transducers (IDTs) on a LiNbO3 substrate.
• Optimization of IDT design and fabrication process for high quality factor (Q) at 6.4 GHz.
• Quantitative analysis of DNA and cell samples using frequency response measurements.

Main Results:

• Achieved a high Q factor (>4000) at 6.4 GHz using optimized IDTs.
• Demonstrated excellent linear response to DNA (1 μg/ml to 1 ng/ml) with sensitivity of 6.7 × 10(-16)g/cm(2)/Hz.
• Successfully performed quantitative detection of single living cancer cells (EMT6) and fibroblast cells (3T3).
• Exhibited high selectivity with insignificant interference and recyclability for cost reduction.

Conclusions:

• The developed SAW biosensor achieves atomic resolution and ultra-high sensitivity.
• It enables precise quantitative detection of DNA and living cells, including cancer cells.
• This technology holds significant potential for advanced medical diagnostics and atomic-level research.