Bacteria-Identifiable 2D Violet Phosphorene-Based Nanosystems for Sepsis Diagnosis and Blood Disinfection

Despite the availability of various bacterial detection and elimination technologies, the sensitive diagnosis and treatment of sepsis caused by bloodstream infections remain significant challenges. Here, we report a magnetic nanosystem VPNS@PEI-Fe3O4-Apt based on functionalized two-dimensional violet phosphorus nanosheets (VPNS) by iron oxide magnetic nanoparticles (Fe3O4), and bacteria-specific recognition aptamers (Apt) for early sepsis diagnosis and complete in vitro blood disinfection. We demonstrated that the VPNS@PEI-Fe3O4-Apt nanosystem can achieve the identification and enrichment of bacterial species in blood, resulting in the successful diagnosis of sepsis caused by a single bacterium (Staphylococcus aureus) or multiple bacteria (Staphylococcus aureus and Escherichia coli). The strategy of VPNS@PEI-Fe3O4-Apt nanosystem has high detection sensitivity (~10 colony-forming units), while significantly reducing diagnostic turnaround time to within 2 h, suggesting that it has great potential for diagnosing early sepsis in clinical therapy. Furthermore, owing to the antibacterial ability derived from the excellent photodynamic (PDT) effect of VPNS and its good biocompatibility, efficient and safe complete disinfection of blood in vitro is achieved. We believe that the VPNS@PEI-Fe3O4-Apt magnetic nanosystem provides a new strategy for bacterial detection and treatment of sepsis.