Unique “posture” of rose Bengal for fabricating personal protective equipment with enhanced daylight-induced biocidal efficiency

Abstract

The aggregation-caused self-quenching of photosensitizers (PS), especially on a solid substrate, has highly limited their photo-induced biocidal efficiency in practical applications. Here, we designed a unique “posture” of rose Bengal (RB) on cotton-based super-adsorptive fibrous equipment, with RB being separately captured in the mesopores of porous organic polymers (POPs). The resultant daylight-induced biocidal cotton fabric with enhanced efficiency was named as DBwEE-Cotton. The enhanced biocidal activity of the DBwEE-Cotton was achieved based on two mechanisms: (1) the separation of RB in mesopores on the fabric avoids the aggregation-caused self-quenching; and (2) other than singlet oxygen generation, RB is forced to undergo type I photoreaction by surrounding the RB with massive amounts of good hydrogen donors (i.e., POP) under daylight irradiation. Given the enhanced production efficiency of reactive oxygen species by the DBwEE-Cotton, 99.9999% of E. coli and L. innocua bacteria were killed within 20 min of daylight exposure. The DBwEE-Cotton also presents excellent wash and light durability with no biocidal function loss. The development of DBwEE-Cotton provides a facile strategy of avoiding aggregation-caused self-quenching and modulating photoreactions of PS on a flexible substrate, which may guide the design of novel personal protective equipment (PPE) integrated with improved biocidal efficiency, wearability, and repeated and long-term applicability for protecting people from lethal infectious diseases.