The use of ultraviolet (UV) and blue irradiation to sterilize surfaces is well established, but commercial applications would be enhanced if the light source is replaced with ambient light. In this paper, it is shown that nanofibers can be explored as an alternative methodology to UV and blue irradiation for bacterial inactivation. It is demonstrated that this is indeed possible using spun nanofibers of poly­[lactic-co-(glycolic acid)] (PLGA). This work shows that PLGA spun scaffolds can promote photoinactivation of Staphylococcus aureus and Escherichia coli bacteria with ambient light or with laser irradiation at 630 nm. With the optimized scaffold composition of PLGA85:15 nanofibers, the minimum intensity required to kill the bacteria is much lower than in antimicrobial blue light applications. The enhanced effect introduced by PLGA scaffolds is due to their nanofiber structures since PLGA spun nanofibers were able to inactivate both S. aureus and E. coli bacteria, but cast films had no effect. These findings pave the way for an entirely different method to sterilize surfaces, which is less costly and environmentally friendly than current procedures. In addition, the scaffolds could also be used in cancer treatment with fewer side effects since photosensitizers are not required.

This work reports the design of a resistive gas sensor based on 2D mats of multi-walled carbon nanotubes (MWCNT). The sensor sensitivity was optimised using chlorine by tuning both MWCNT network morphology and MWCNT electronic properties. Raw CNT were compared with annealed CNT. Besides, with the aim to enhance the sensor sensitivity and selectivity for detection of several gases, MWCNT were functionalized with poly (phenylene)-like or vinyl polymers using a process based on the diazonium chemistry. In this paper, we will mention the preparation of such sensors and we will demonstrate that the optimized devices are operating at room temperature, for the detection of pollutants such as chlorine, hydrogen chloride and ammonia. Such sensors are able to detect down to 30 ppb of pollutant, in particular for chlorine.