Quantification of Staphylococcus aureus using surface acoustic wave sensors

Quartz crystal microbalance (QCM), surface acoustic wave (SAW)-Rayleigh and ZnO based SAW-Love sensors were fabricated and their sensitivity was comparatively analyzed for the quantification of Staphylococcus aureus (S. aureus). The SAW based sensors showed response magnitudes up to three times greater than that of the QCM sensor for the same mass loading of S. aureus. The ZnO nanoparticle-based SAW-Love sensor has a maximum mass loading sensitivity of 328.75 Hz ng^-1. The SAW-Love sensor achieved a lower limit of detection of 2 × 10³ CFU mL^-1 compared to the QCM counterpart (2 × 10⁵ to 2 × 10⁶ CFU mL^-1) under the same conditions. The SAW-Love sensor could be used as a disposable chip in micro or ultra-trace accurate diagnosis methods.