Monitoring Gene\nSequences of Staphylococcus\naureus Using a Love-Mode Surface Acoustic Wave Biosensor\nCoated with Cellulose Acetate/Polyethylenimine Nanofibers and Au Nanoparticles

Love-mode surface acoustic wave (SAW) sensors show great\npromise\nfor biodetection applications owing to their low cost, digital output,\nand wireless passive capability, but their performance is often restricted\nby the availability of suitable sensitive membrane layers. Herein,\na composite layer of electrospun fibers made from cellulose acetate\nand polyethylenimine, coated with gold nanoparticles, is proposed\nas a porous and sensitive membrane coated onto a love-mode SAW biosensor\nfor monitoring gene sequences of Staphylococcus aureus. The results showed that the developed sensor exhibited an impressive\nsensitivity of 122.56 Hz/(nmol/L) for detecting gene sequences of S. aureus, surpassing the sensitivity of conventional\nSAW sensors employing a bare Au film as the sensitive layer by 5-fold.\nThe analysis revealed a remarkably linear detection (R<sup>2</sup> of 0.97827) of S. aureus gene sequences\nwithin the range of 0 to 100 nmol/L. The limit of detection was impressively\nlow at 0.9116 nmol/L. The good stability and specificity of the biosensor\nin liquid environments were demonstrated for clinical diagnostics.