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Black phosphorus (BP) exhibits great potential as antibacterial materials due to its unique photocatalytic activity. However, the unsatisfactory optical absorption and quick recombination of photoinduced electron–hole pairs restrain its photocatalytic antibacterial performance. In this work, silver nanoparticles (AgNPs) were decorated on BP to construct BP@AgNPs nanohybrids and then introduced into poly-l-lactic acid scaffold. Combining the tunable bandgap of BP and the LSPR effect of AgNPs, BP@AgNPs nanohybrids displayed the broaden visible light absorption. Furthermore, AgNPs acted as electron acceptors could accelerate charge transfer and suppress electron–hole recombination. Therefore, BP@AgNPs nanohybrids achieved synergistically enhanced photocatalytic antibacterial activity under visible light irradiation. Fluorescence probe experiment verified that BP@AgNPs promoted the generation of reactive oxygen species, which could disrupt bacteria membrane, damage DNA and oxide proteins, and finally lead to bacteria apoptosis. As a result, the scaffold possessed strong antibacterial efficiency with a bactericidal rate of 97% under light irradiation. Moreover, the scaffold also exhibited good cytocompatibility. This work highlighted a new strategy to develop photocatalytic antibacterial scaffold for bone implant application.

Black phosphorous (BP) is recognized as an effective reinforcement for polymer scaffold because of its excellent mechanical property and biocompatibility. Nevertheless, its poor stability in physiological environment limits its application in bone repair. In this work, BP was modified with dopamine by self-polymerization approach (donated as BP@PDA) to improve its stability, and then was introduced into poly-L-lactic acid (PLLA) scaffold fabricated by selective laser sintering technology. Results showed the compressive and tensile strength of PLLA/BP@PDA scaffold were improved by 105% and 50%, respectively. The enhanced strength was ascribed to the increased stability of BP and the improved compatibility of BP@PDA with PLLA matrix after modifying with polydopamine. Simultaneously, the bioactivity of PLLA scaffold was significantly improved. It was attributed to that BP@PDA provided the sustained source of PO43- ions which could capture Ca2+ ions from physiological medium to facilitate in situ biomineralization, thereby promoting cell adhesion, proliferation and differentiation. This study demonstrated the great potential of BP@PDA in bone repair.