High sensitive optical fiber SPR biosensor enhanced by Ti₃C₂Tₓ MXene for label-free detecting Staphylococcus aureus

Rapid and accurate pathogen detection is critical for optimizing clinical decision-making within precision medicine frameworks, specifically for identifying Staphylococcus aureus (S. aureus) in wound infections. Most of conventional detection methods suffer from procedural complexity, protracted analysis times, and insufficient sensitivity, thereby constraining their clinical deployment. In this work, an optical fiber surface plasmon resonance (SPR) sensor enhanced by Ti 3 C 2 T x MXene was developed for detecting S. aureus , biofunctionalized with goat anti-human immunoglobulin G (IgG). The optimal thickness of Ti 3 C 2 T x MXene layer, determined to be approximately 94 nm based on maximizing figure of merit (FOM) of 17.88 RIU −1 , yielded high sensitivity and low full width at half maximum (FWHM). By monitoring SPR wavelength shifts in the transmission spectra, the sensor was employed to detect S. aureus with a low limit of detection (LOD) of 1.14 CFU/mL and a high sensitivity of 3.063 nm/log (CFU/mL). It exhibited excellent linearity across the concentration range of 10 2 –10 8  CFU/mL, alongside high stability and selectivity. Validation using S. aureus -infected wound tissue from diabetic murine models exhibited a precision exceeding 97 %. This technology represents a promising avenue for developing next-generation, high-performance biosensing platforms with significant translational potential in precision medicine diagnostics.