{
  "abstract": "Innovative packaging solutions, namely smart packaging, have recently been explored to combat challenges in the food system, such as reducing food waste, preventing foodborne diseases, and food fraud. One of the most interesting materials recently explored in this context is carbon dots (CDs), which could be used to develop traceability and anti-counterfeiting solutions. As such, this work aimed to use bio-derived CDs to develop extruded CD-loaded low-density polyethylene (LDPE) films foreseeing its use as invisible tags in food packaging. Bio-derived CDs were produced via hydrothermal synthesis using sodium alginate and urea and present a spherical morphology, a size of 5.6 ± 1.7 nm, display blue fluorescence (λexc=~335 nm; λem=~410 nm), and a quantum yield of 5.53 %. Surface analysis of the CDs shows that nitrogen incorporation was successful, with the CDs composed of carbon, oxygen, nitrogen, and sodium. The CDs exhibited excitation-dependent emission consistent with their complex surface chemistry and demonstrated high biocompatibility (>90% in a cytotoxicity assay). Chemical and optical characterisations (XRD, Raman, FTIR, XPS) seem to indicate that the produced CDs are carbonised polymer dots (CPDs). LDPE Films were produced via blown-film extrusion and characterised regarding their morphology, fluorescence, transparency, mechanical and barrier properties, as well as their migration behaviour. Transparent and mechanical properties remained mostly unchanged and migration of CDs from the LDPE films was absent, while CD-loaded films displayed blue fluorescence under UV light (365 nm). Overall, the CD-loaded films displayed a similar behaviour to the control across all assays, indicating that the CD incorporation does not induce significant changes to the LDPE films. The highest loading of CDs in LDPE films displayed blue fluorescence, confirming their potential for use as traceability, recyclability, and anti-counterfeiting solutions.",
  "abstract_shown": true,
  "affiliations": [
    "International Iberian Nanotechnology Laboratory (INL, Av. Mestre José Veiga, Braga, Portugal, 4715-330",
    "Centre of Physics of the Universities of Minho and Porto",
    "University of Minho",
    "Silvex - Industrial Plastics and Paper SA"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Pedro M. Silva",
      "orcid": "0000-0002-3744-1999"
    },
    {
      "affs": [
        0
      ],
      "name": "A. Gabriela Azevedo"
    },
    {
      "affs": [
        0
      ],
      "name": "Artur J. Martins"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "M. Fátima Cerqueira"
    },
    {
      "affs": [
        3
      ],
      "name": "Graça Brotas"
    },
    {
      "affs": [
        0
      ],
      "name": "Lorenzo M. Pastrana"
    },
    {
      "affs": [
        0
      ],
      "name": "Miguel A. Cerqueira"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3tebrff2n67g8.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15008691/v1",
  "fulltext_url": null,
  "id": "3tebrff2n67g8",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008691/v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2505|Carbon and Quantum Dots Applications"
    ]
  ],
  "openalex": "W7212285827",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15008691/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-11",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/3tebrff2n67g8.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:19Z",
      "native_id": "10.26434/chemrxiv.15008691",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008691/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2505|Carbon and Quantum Dots Applications",
      "subfield": "materials-polymers"
    }
  ],
  "title": "Bio-based carbon dot-loaded polyethylene films for smart packaging applications",
  "title_text": "Bio-based carbon dot-loaded polyethylene films for smart packaging applications",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:19Z",
  "url": "https://research.draconitic.com/paper/3tebrff2n67g8",
  "venue": "ChemRxiv",
  "versions": []
}