Green light–triggered antimicrobial cotton fabric for wastewater disinfection

Abstract

Water pollution by pathogenic bacteria is a major threat to human health, and less-than-ideal disinfection and antimicrobial strategies have been developed to address waterborne pathogens. A green light–triggered photocatalytic antimicrobial rose bengal (RB)–modified cotton fabric (CF) (RB-CF) was prepared for wastewater disinfection by covalently binding RB to a CF surface. The antimicrobial rates of RB-CF against gram-positive Staphylococcus aureus and gram-negative Escherichia coli were both greater than 99.99% due to the generation of singlet oxygen that inactivates microbes under green light irradiation. Most importantly, RB-CF exhibited high stability, negligible cytotoxicity, and no release of free RB during the photocatalytic process, which was the key to its long-term antimicrobial activity and use security. Its long-term antimicrobial activity was further verified by the repeated photocatalytic disinfection; more than 99.99% of bacteria were inactivated even after five cycles. Therefore, this work may offer a potential avenue to develop low-cost, non-toxic, and durable antimicrobial fabrics with great potential for industrial and health-care applications, including but not limited to water purification, wastewater disinfection, masks, and protective clothing.