Daylight-driven rechargeable antibacterial and antiviral nanofibrous membranes for bioprotective applications

Si, Yang; Zhang, Zheng; Wu, Wanrong; Fu, Qiuxia; Huang, Kang; Nitin, Nitin; Ding, Bin; Sun, Gang

A systematic design of desired antimicrobial bioprotective materials requires an optimization of two important characteristics: the biocidal activity, as a capacity of the killing of microbial pathogens, and the renewability of the biocidal functions, which affects the durability and reusability in a long-term usage (20, 21) . Rechargeable biocidal halamine materials have been developed and extensively investigated in recent years, and their functions can meet the basic requirements of bioprotection (22, 23) . However, the use of a chlorine bleach solution as a recharging agent puts limitations on applications. Photo-induced antimicrobial materials, as the forefront of advanced and green materials, have high biocidal efficiency, ease of activity recharging, broad-spectrum biocides, long-term stability, high durability, and low toxicity with little environmental concern (24, 25) . These materials would be, in this regard, a great promise as an exceptional candidate for constructing bioprotective equipment. Despite their outstanding potential, the major problem associated with the photoantimicrobial materials is their solely photo-driven biocidal character, with the instantaneous biocidal function fast decaying or quenching under dim light and dark conditions (26, 27) . Moreover, most of these products were driven by high-energy ultraviolet (UV) light rather than the readily available daylight source (28, 29) , which are often energetically and operationally intensive, focused on specialized UV irradiation systems, thus significantly limiting the usability for bioprotection. Therefore, the challenge is to construct a daylight-driven, rechargeable, and antimicrobial material capable of working under both light and dark conditions, without compromising the interception performance against tiny pathogenic particles.