Quantification of Staphylococcus aureus using surface acoustic wave sensors

Area of Science:

• Biosensing
• Nanomaterials
• Microgravimetric analysis

Background:

• Accurate quantification of Staphylococcus aureus (S. aureus) is crucial for clinical diagnostics and food safety.
• Existing biosensors like Quartz Crystal Microbalance (QCM) have limitations in sensitivity and detection limits.
• Surface Acoustic Wave (SAW) sensors offer potential for enhanced biosensing applications.

Purpose of the Study:

• To comparatively analyze the sensitivity of QCM, SAW-Rayleigh, and ZnO-based SAW-Love sensors for S. aureus quantification.
• To evaluate the performance of ZnO nanoparticle-based SAW-Love sensors for ultra-trace accurate diagnosis.

Main Methods:

• Fabrication of Quartz Crystal Microbalance (QCM) and Surface Acoustic Wave (SAW) sensors (SAW-Rayleigh and SAW-Love).
• Utilized ZnO nanoparticles in the SAW-Love sensor construction.
• Comparative analysis of sensor response and mass loading sensitivity for S. aureus.

Main Results:

• SAW-based sensors exhibited up to three times greater response magnitude than QCM for the same S. aureus mass loading.
• The ZnO nanoparticle-based SAW-Love sensor achieved a mass loading sensitivity of 328.75 Hz ng⁻¹.
• SAW-Love sensors demonstrated a significantly lower limit of detection (2 × 10³ CFU mL⁻¹) compared to QCM sensors (2 × 10⁵–2 × 10⁶ CFU mL⁻¹).

Conclusions:

• ZnO-based SAW-Love sensors provide superior sensitivity and a lower limit of detection for S. aureus compared to QCM sensors.
• The developed SAW-Love sensor is suitable for disposable chip applications in micro- or ultra-trace accurate diagnostic methods.
• This technology holds promise for rapid and sensitive detection of bacterial pathogens.