Surface Plasmon Resonance Detection of Staphylococcus Aureus Pathogen

Surface Plasmon Resonance sensors have attracted attention due to their high detection ability and sensitivity. In this study, a SPR biosensor is developed to detect pathogens, such as Staphylococcus aureus (S. aureus). A spectrophotometer, polarization sheet, attenuator, and supercontinuum white light source were all part of the developed proposed system. The SPR platform was fabricated of a gold metal of 53 nm as a plasmonic surface to sense the change in the surrounding refractive index (RI). The serial dilution method was conducted to prepare <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$S$</tex>. aureus bacteria with different solution concentrations, where the sterilized deionized water is used as a diluent. The SPR lambda change of the reflectance spectrum was detected of each bacterial analyte while keeping the SPR angle fixed at 72°. The SPR wavelength shift was related to the DI. water as a control sample exhibiting excellent linearity of an <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{R}^{2}$</tex> equals 0.98 of a range of detection of 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup>–10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> CFU/mL. The sensor's log sensitivity (LS) was calculated to be 4.9103 nm/ (log CFU/mL).