Dual-functionalized luminescent/photodynamic composite fabrics: Synergistic antibacterial activity for self-disinfecting textiles

For the purpose of developing self-disinfecting photodynamic textiles with enhanced antibacterial activity, here we report a scalable and facile method to immobilize the long persistent phosphor SrAl2O4:Eu2+ , Dy3+ (SAOED) and the photosensitizer Rose Bengal onto cotton fabric (CF) by knife coating and photocrosslinking methods. The resultant composite material, termed SAOED/RB-CF, exhibited superior synergistic antibacterial efficacy capable of 99.999% (5 log units, detection limit) and 99.986% (3.9 log units) photoinactivation against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA), respectively, under visible-light illumination (Xenon lamp). Mechanistic studies employing both substrate photooxidation and EPR spin-trapping methods demonstrated an enhanced yield of singlet oxygen (O-1(2)) production compared to the RB/CF material alone (without the phosphor), suggesting that the light emitted from the phosphorescence of the photoexcited SAOED could be absorbed by the RB photosensitizer under dark conditions, resulting in effective synergistic pathogen inactivation. In addition, the SAOED/RB-CF composite fabric possessed excellent abrasion resistance, mechanical strength and color fastness. Our findings suggest that the integration of long persistent phosphors into photodynamic materials may provide a new avenue to explore for developing composite fabrics as applied materials in infection control applications for use in both healthcare environments and consumer textiles.

Automated summary

In this study, a scalable and facile method to immobilize long persistent phosphor and photosensitizer onto cotton fabric was reported. The resulting composite material exhibited superior antibacterial activity against Staphylococcus aureus and methicillin-resistant S. aureus under visible-light illumination. Mechanistic studies showed enhanced singlet oxygen production, resulting in effective pathogen inactivation. In addition, the composite fabric possessed excellent abrasion resistance, mechanical strength, and color fastness. These findings suggest the potential of using long persistent phosphors in composite fabrics for infection control applications.