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

As a proof of concept for bioprotective PPE application, the charged BDCA-RNM (1 hour of daylight irradiation) was stuck to the typical respirator and protective suit as a covering layer to bring the desired biocidal functions. It is well known that the transmission of pathogens contained in aerosol droplets plays a significant contribution to the spread of airborne diseases, and the surgical masks were suggested as the major inhalational barrier to protect HCWs (8, 10) . As shown in Fig. 5D , 1 × 10 6 CFU of E. coli-containing aerosols with the diameter of 1 to 5 mm were prepared as model infection aerosols, which was similar to the size of aerosols generated by a human sneezing or coughing. A charged BDCA-RNM with a size of 2 × 2 cm 2 was stuck on the right side of a 3M N100 respirator, and the respirator was exposed to a 0.2 ml min −1 of aerosols flow for 30 s. After standing for 30 min, the population of the living bacteria on the three representative areas-control area, BDCA-RNM area, and the covered area-were harvested and measured (Fig. 5E ). As shown in Fig. 5F , the E. coli loaded on the control area exhibited high activity with free growth and proliferation, which was due to the nonbiological function of the traditional nonwoven materials. In contrast, no live bacteria were detected on the BDCA-RNM area or the relevant covered area, indicating the robust protection against the pathogens. Similarly, the charged BDCA can also bring about promising bioprotection against the model virus to the typical protective suit, as demonstrated in Fig. 5 (G to I) . These results indicate that the BDCA-RNM could serve as a scalable biocidal layer that not only intercepts but also effectively kills pathogens either in aerosols or in liquid forms, implying its potential broad applications in bioprotective PPE against the increasing EID threats.