Smart bactericidal textile enabling in-situ visual assessment of antimicrobial activity

Hospital fabrics and wound dressings with antibacterial properties are essential to minimize infection risks associated with bacterial colonization of textiles. A key challenge of these materials lies in the difficulty in assessing their functional lifespan. Integrating bacterial-sensing elements into smart textiles enables real-time and in-situ evaluation of antibacterial activity. However, this approach is often hindered by the reactivity between bactericidal and bacterial-sensing components, the limited stability and selectivity of the sensing probes, and high production costs. Here, we address these challenges by presenting a smart textile that simultaneously provides antibacterial activity and bacterial-sensing capacity using a layer-by-layer sonochemical deposition method. Prussian blue, a chromogenic bacterial-sensing probe, is integrated onto hospital-grade antibacterial fabrics containing copper oxide nanoparticles. When the biocidal fabric begins to lose its antimicrobial activity, live bacteria in the textile metabolically reduce Prussian blue nanoparticles, triggering a visible colour change. This approach offers several key advantages, such as: (i) the resulting textile retains antibacterial activity comparable to conventional copper oxide-based textiles (A value > 4 in both cases); (ii) it provides a direct and visible colour transition from blue to colourless (>20 % colour losses) when the antibacterial coating begins to lose effectiveness, enabling straightforward monitoring of antibacterial lifespan without external instruments or reagents; (iii) the co-immobilization enhances coating stability, nearly doubling the binding strength of copper oxide and Prussian blue compared to single-layer coatings; and (iv), the additional Prussian blue layer significantly reduces the material cytotoxicity, enhancing biocompatibility for safer use in healthcare settings. These innovations offer a scalable, cost-effective, and multifunctional solution for infection control. The smart textile not only prevents bacterial spread but also provides timely, visual indications of coating degradation, making it a promising tool for improving patient safety in hospitals and for minimizing infection risks in schools and other high-risk environments.