| Abstract Scope |
Listeria monocytogenes is a deadly foodborne bacterium that requires rapid, sensitive detection in real-world food matrices. Two-dimensional MXenes, such as Ti₃C₂Tₓ and Mo₂TiC₂Tₓ, emerged as promising SERS-active materials for biosensing. In this work, we compare Ti₃C₂Tₓ and the double transition metal Mo₂TiC₂Tₓ MXene, with a focus on how differences in their flake size, defect density, and surface chemistry influence in‐situ self-reduction of gold nanoparticles (AuNPs) and the resulting SERS performance for L. monocytogenes detection.
The Mo₂TiC₂Tₓ–Au sensor used 4-mercaptobenzoic acid as a Raman reporter and antibody conjugation for specificity, achieved a detection limit around 10² CFU/mL and successfully distinguished L. monocytogenes in phosphate buffer and spiked lettuce samples.
While the defect-rich, smaller flakes of Mo₂TiC₂Tₓ maximize SERS enhancement, they displayed reduced long-term stability compared to the larger Ti₃C₂Tₓ flakes. This shows that there is a materials design trade-off. Nevertheless, the dramatically lower Au requirement demonstrates a cost-effective fabrication advantage. |