Single-Stroke Metal Nanoparticle Laser Scribing on Cellulosic Substrates for Colorimetric Paper-Based Device Development

A straightforward CO₂ laser-plotter-based technique to obtain different types of metal nanoparticles on paper is presented. This strategy allows the instantaneous laser-induced generation of metal nanoparticles (LIMs) anchored onto cellulosic substrates with micrometric resolution and customizable patterns; Au, Ag, Pt, Ni, and Cu LIMs have been obtained. LIM features were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. LIMs are plasmonic-active and characterized by colorimetric features consistent with nanostructure chemistry and density. Arrays of LIMs were assembled in two paper-based formats: (i) a nanocatalytic multimetal comb-shaped device to prove LIMs’ remediation ability for the switch-off of organic dyes and (ii) a paper-based nano colorimetric LIM array challenged for peracetic acid (PAA) vapor sensing, useful in the area of environmental sanitization. LIM nanochemistry allows (i) rapid (<1 min) organic dye catalytic conversion and (ii) sensitive PAA detection (LOD ≤ 0.3 μg mL^–1) capable of discriminating PAA exposure levels from 0.5 to 60 mg m^–3. LIM-based devices returned reproducible data (RSD ≤ 15%, n = 3). Summing up, the proposed strategy is particularly prone to generate catalytic/sensing zones in tailored paper-based devices, resulting in a new sustainable nanopatterning technique appealing in the (bio)­sensing and nanochemistry fields.