MXene-incorporated interconnected porous heterostructure for Staphylococcus aureus capture and surface enhanced Raman scattering analysis.

Staphylococcus aureus (S. aureus) is a foodborne pathogen threatening public health due to the lack of rapid and sensitive detection methods for timely identification of its contamination. Surface-enhanced Raman scattering (SERS) shows great potential in quick bio-detection, but its pathogen detection analysis is challenged by limited size-matched substrates for both pathogen separation and SERS enhancement. Here, we designed an MXene-incorporated interconnected porous heterostructure (MIIPH) for effective capture and SERS detection of S. aureus. The MIIPH is fabricated through a one-pot hybridization process that incorporates single Ti3C2Tx MXene layers during the construction of the interconnected porous hydrogel. It enables S. aureus capture through both Ti-phosphate coordination and the boronic acid-diol binding interactions. Notably, owing to its highly uniform interconnected porous nanoarchitecture, MIIPH enhances the retention of S. aureus via a spatial confinement effect. Combined with a SERS-active silver probe (Ag-Apt), S. aureus is encapsulated within MIIPH and coated with Ag-Apt, enabling stable encapsulation of S. aureus within the interconnected porous network, while also providing synergistic SERS enhancement from both the embedded MXene component in MIIPH and silver plasma. This platform achieves S. aureus capture and determination with good sensitivity (a detection limit of 151 CFU/mL) and high specificity across a wide linear range (1.51 × 10³1.51 × 10⁸ CFU/mL). Furthermore, the method was successfully applied to the analysis of rice samples. Our approach not only provides a determination tool for S. aureus in complex matrices but also offers a versatile guideline for designing pathogen-specific SERS substrates.