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

produced continuously under light irradiation. ROS could further rapidly damage DNA, RNA, proteins, and lipids, resulting in bacterial death and virus inactivation (33, 34) . Our proposed mechanism of the photoactive and photo-storable biocidal functions is demonstrated in Fig. 1 (E and F) . The initial photoreaction hinges on the ability of the photoexcited RNM to access the triplet excited state ( 3 RNM*) via intersystem crossing (ISC), which may be of local excitation or charge transfer character, depending on the relative configuration of the p* orbital. Thereafter, 3 RNM* can abstract a hydrogen atom from a hydrogen donor to form a quinone radical (RNMH•). Under aerobic conditions, the RNMH• would be trapped by oxygen molecules, going back to RNM and simultaneously yielding active ROS (35, 36) . Meanwhile, if the generated RNMH• was not fully quenched by oxygen, then a competing reaction, including structure rearrangement and a second hydrogen abstraction, could occur, leading to the formation of a metastable structure that stores the activity. This activity could readily release in the form of generating ROS, even under dark conditions. The detailed reactions related to the photoactive and photo-storage cycles are schematically presented in fig. S9 .