MOF-based controlled-release patches for nitric oxide: fabrication, gas release profile, and preservation efficacy on cherry tomatoes

This study develops MOF patches for controlled NO release in produce preservation. • MOF loading effectively protects NO donors from loss during wet-casting fabrication. • Three metal-node MOF patches enable differential NO release profiles. • Patch integrates moisture absorption, microorganism and respiration inhibition. • MOF patches significantly extend produce shelf life while reducing precursor loss. Nitric oxide (NO) preservation suffers from instability and safety issues via conventional single-exposure treatments, while wet-casting methods cause substantial NO donor loss. This study developed metal-organic framework (MOF)-mediated controlled-release patches to address these limitations. Three MOFs (Cu-MOF, Zn-MOF, Fe-MOF) with distinct pore structures were synthesized, achieving 26.9%–38.2% L-arginine loading. The resulting gelatin-polyacrylic acid sodium hydrogel patches exhibited tensile strength of 3.03–4.84 MPa and elongation at break of 131.3%–240.1%, and dissolution rates of 12.4%–17.2%. They also showed significant antimicrobial activity against E. coli, S. aureus, and A. niger . MOF loading elevated precursor utilization efficiency to 70%–82.5%. The patches achieved sustained release of H₂O₂ (8.0–9.6 mmol/g) and NO (41.7–50.6 ppm) over 12 days, extending cherry tomato shelf life to 12 days at room temperature while maintaining total bacterial levels within safe limits. This work establishes MOF-mediated controlled release for green preservative gas utilization. Download: Download high-res image (189KB) Download: Download full-size image