https://hdl.handle.net/10259/4314 Fri, 17 Apr 2026 09:46:38 GMT 2026-04-17T09:46:38Z https://hdl.handle.net/10259/11488 Coumarin-inspired light-responsive thermoplastic adhesives for recyclable multilayer packaging Sedano Labrador, Carlos; Herrero, Manuel; Trigo López, Miriam; Rodríguez Pérez, Miguel Ángel .; Merino, Juan Carlos; García Pérez, José Miguel; Vallejos Calzada, Saúl; Núñez-Carrero, Karina C. Multilayer plastic packaging offers essential barrier and mechanical properties for food preservation, but its complex structure prevents effective recycling. Here, we report a light-responsive thermoplastic adhesive designed to enable on-demand separation of polymer layers in multilayer packaging. The adhesive adopts a triblock architecture with terminal blocks compatible with polyethylene (PE) and polyamide (PA), and a central segment functionalised with coumarin-based photoremovable groups. Upon ultraviolet (UV) exposure, the adhesive undergoes complete molecular breakdown, triggering clean delamination without solvents or mechanical force. Fabricated PE – photosensitive adhesive – PA films demonstrated superior adhesion performance compared to a commercial benchmark during service life, and efficient separation upon irradiation, as confirmed by Fourier transform infrared (FTIR) spectroscopy, microscopy, and T-peel testing. Life cycle assessment revealed that, while the laboratory-scale synthesis has higher environmental costs, the impact is offset after a single reuse cycle in projected industrial conditions, reaching up to 80% reduction after six cycles. This approach provides a scalable strategy to reconcile performance and recyclability in multilayer packaging. Thu, 01 Jan 2026 00:00:00 GMT https://hdl.handle.net/10259/11488 2026-01-01T00:00:00Z https://hdl.handle.net/10259/11487 Naked-eye detection of Listeria monocytogenes using smart chromogenic polymers with tuneable surface morphologies Arnáiz Alonso, Ana; Melero Gil, Beatriz; Trigo López, Miriam; Mendía Jalón, Aránzazu; Fuente Vivas, Dalia de la; Iñigo Martínez, María Emilia; Gómez Cuadrado, Laura; Ibeas Cortes, Saturnino; Vallejos Calzada, Saúl Listeria monocytogenes is a major foodborne pathogen associated with listeriosis, with a mortality rate of up to 30 %. Conventional detection methods are often time-consuming and require sophisticated equipment or complementary techniques to ensure sensitivity and specificity. This study presents a smart chromogenic polymeric sensor for the rapid detection of L. monocytogenes based on the activity of phosphatidylinositol-specific phospholipase C (PI-PLC). Six hydrophilic polymer films with identical compositions but different surface properties were developed, incorporating a chromogenic substrate that produces a visible colour change upon enzymatic hydrolysis, allowing the direct visual identification of L. monocytogenes. The sensitivity and specificity were assessed against a panel of foodborne bacteria, with detection limits of 104 CFUs/mL. Among the tested materials, NC2sf, Ff, and Sf showed the highest sensitivity and limited cross-reactivity with L. ivanovii, Staphylococcus aureus, and Bacillus cereus. Biocompatibility assays in HepG2 cells confirmed acceptable cytocompatibility, underscoring the importance of substrate selection for minimising adverse cellular effects. A proof-of-concept test on chicken breast slices and fresh-cut melon demonstrated the specific detection of L. monocytogenes and clear discrimination from non-pathogenic L. innocua, confirming the robustness and selectivity of the system. Finally, a Life Cycle Assessment highlighted the environmental impact of the sensing materials and provided insights into their potential pre-industrial scalability. Sun, 01 Mar 2026 00:00:00 GMT https://hdl.handle.net/10259/11487 2026-03-01T00:00:00Z https://hdl.handle.net/10259/11026 Multifunctional smart polymers and citizen science for a comprehensive approach to nitrate pollution: Curative and preventive strategies Vallejo García, Jorge Lucas; Hernández Ruiz, Raquel; Torija López, Alba; Trigo López, Miriam; Ibeas Cortes, Saturnino; Gómez Cuadrado, Laura; Martel Martín, Sonia; Barros García, Rocío; Vallejos Calzada, Saúl This work presents the development and evaluation of a multifunctional smart polymer (FNO₃) for the extraction and detection of nitrates in drinking water. A total of 250 tap water samples from various localities were analyzed, revealing nitrate concentrations that in some cases doubled the legal limit (up to 100 mg⋅L⁻¹). FNO₃, composed of 49.75 mol% NNZA monomer with high anion-exchange capacity, exhibited a maximum nitrate adsorption capacity (qmax) of 164 ± 5 mg⋅g⁻¹ , which is 3.6 times greater than that of commercial resins. The polymer demonstrated significant swelling in water (~2014 ± 152 %) and incorporated a sensing functionality via a fluorometric monomer, enabling visual detection when saturation occurs. Fluorescence response studies yielded a limit of detection (LOD) of 4.26 mg⋅L⁻¹ and a limit of quantification (LOQ) of 12.92 mg⋅L⁻¹ , values that are below the regulatory thresholds established by European and Spanish legislation for nitrates in drinking water. The material was tested through multiple adsorption-regeneration cycles using domestic saline solutions, maintaining stable efficiency. Interference studies indicated that carbonates present in hard water partially reduce adsorption effectiveness. Life Cycle Assessment (LCA) identified the structural materials and functional monomers as the main contributors to environmental impact, while reuse and polymer application offer environmental benefits due to nitrate recovery. Additionally, in vitro toxicological assays with HepG2 cells confirmed the absence of cytotoxicity, supporting the polymer’s viability for safe water treatment applications. Sat, 01 Nov 2025 00:00:00 GMT https://hdl.handle.net/10259/11026 2025-11-01T00:00:00Z https://hdl.handle.net/10259/11013 Natural mediators for indigo carmine dye removal with immobilized laccase in polyacrylic films Vallejo García, Jorge Lucas; Trigo López, Miriam; Ibeas Cortes, Saturnino; García García, Félix Clemente; Busto Núñez, Mª Dolores; Núñez-Carrero, Karina C.; Alonso-Pastor, Luis E.; Vallejos Calzada, Saúl This work presents a new polymeric material in the form of a film (FLAC) containing immobilized laccase enzyme through diazo bonds, designed for the degradation of indigo carmine dye, which is highly toxic and commonly found in wastewater from the textile industry. The immobilization of the enzyme in the film was characterized by SEM, FT-IR, DSC, TGA and EDXS. The degradation of the dye by FLAC initiates in the presence of a mediator due to the high redox potential of the dye. Six natural mediators (ferulic acid, syringaldazine, guaiacol, eugenol, thymol, and p-coumaric acid) were tested, and complete degradation of the dye was achieved in 180 min, with a mediator concentration of 1 ppm (syringaldazine) and a dye concentration of 10 ppm. A novelty in this study is the short exposure time of the dye-mediator solution to FLAC (15 min) which allowed the degradation process to continue autonomously after the film was removed. Additionally, it was observed that the material was more effective in the presence of textile washing products, achieving over 99 % degradation in 40 min, surpassing its efficacy in distilled water. Regarding reusability, the material retained >90 % of its activity after five cycles of use and washing. Life Cycle Assessment (LCA) and Techno-Economic Analysis (TEA) identified key levers for techno-economic and environmental viability: shorten cycle time (surfactant media), maximise re-use and per-cycle volume/concentration, implement solvent recovery, and energy decarbonization thereby outlining a roadmap to sustainable scale-up. Mon, 01 Dec 2025 00:00:00 GMT https://hdl.handle.net/10259/11013 2025-12-01T00:00:00Z