Paper-based luminescent filters for smart detection of nanomaterials in workplace exposure assessments

The growing use of nanomaterials in industrial environments raises concerns about potential occupational health risks, highlighting the need for effective tools to detect and monitor worker exposure. In this work, we present paper-based luminescent sensors for airborne nanoparticle detection, based on cellulose filters functionalized with polyvinyl alcohol incorporating either carbon dots or water-soluble organic dyes. The photostability of the functionalized papers was systematically evaluated, showing that the LUWSBLUE1® (LB1) dye embedded in PVA exhibits superior stability compared to carbon dot-based systems. The sensing performance of LB1@PVA papers was assessed using different nanoparticles with sizes ranging from 5 to 500 nm, in powder form and under airborne dispersion. In all cases, nanoparticle exposure induced a local reduction of luminescence intensity, detectable by spectrofluorometry and visual inspection under UV light. Finally, the functionalized papers were integrated into an airborne monitoring system, demonstrating efficient and reliable collection of silica nanoparticles across the investigated size range. These results indicate that LB1@PVA paper sensors are promising low-cost and user-friendly tools for monitoring nanoparticulate pollutants in occupational settings.