TMD Nanosheets with Abiotic Recognition Phases for Pathogen Detection and Inactivation

Antibodies are representative recognition molecules selectively binding to target antigens, leading to wide applications for sensing and therapy. However, antibodies have some limitations such as low stability, long production time, and high cost. Thereby, there is an increasing demand for the development of alternative recognition molecules in theragnosis. Several biomimetic strategies have been developed to circumvent these limitations, including molecular imprinting, peptoids, and engineering nanointerfaces. Despite these efforts, it is still of great interest to devise an effective strategy to mimic antibodies for simultaneous sensing and therapy. Herein, we report an effective approach for the design of biomimetic nanohybrids capable of the selective recognition and inactivation of pathogenic bacteria. Tripeptides with a nitriloacetate-Cu group were spontaneously assembled on transition metal dichalcogenide (TMD) nanosheets (TMD-TP) to form abiotic recognition phases for target bacteria, producing various types of TMD-TP antibody mimics. The resulting TMD-TP antibody mimics exhibited strong Raman scattering signals for bacterial sensing and photothermal effect under infrared irradiation for bacterial inactivation. The recognition mechanism of TMD-TP antibody mimics against the specific bacteria was thoroughly investigated by experiments and molecular dynamics simulations. Finally, the TMD-TP antibody mimics could sensitively recognize each target bacteria up to a single copy from human serum and urine in a rapid manner. In addition, the MoSe₂-CHC antibody mimic was successfully applied for the effective eradication of <i>S. typhimurium</i> infecting the wounds of mice under NIR irradiation. These biomimetic nanohybrids can be extended to theragnosis of a variety of biomolecules.