Eradication of Gram-negative bacteria by reusable carbon nitride-coated cotton under visible light

A metal-free graphitic carbon nitride (GCN-T) photocatalyst obtained through a microwave-assisted technique was immobilised on cotton fabrics by an exhaustion method. Coated-cotton with only 0.81 % (w/w) of GCN-T (CO/GCN-T) presented effective antimicrobial properties against pathogenic bacteria, P. aeruginosa and E. coli, eradicating the retained bacteria after 60 min of direct irradiation with visible light. The self-cleaning activity of CO/GCN-T samples was also proved for the degradation of Rhodamine B (RhB) stains after 60 min of irradiation with a cost-effective Light Emitting Diode (LED) (λmax = 417 nm). In addition, CO/GCN-T did not hinder the growth of commensal skin bacteria Staphylococcus spp. and presented non-cytotoxicity to skin cell lines, such as fibroblasts (L929) and keratinocytes (HaCaT), so it can be stated that these textiles are promising for applications in direct contact with the skin. Therefore, these are relevant findings since a textile substrate, with the ability to remove or eliminate harmful microorganisms, is an asset for the healthcare area.