{
  "abstract": "Sunlight-assisted plant-mediated synthesis of silver nanoparticles (AgNPs) is well established, yet the complementary use of fluorescence spectroscopy to examine the optical response of complex phytochemical-containing media remains of interest. Here, Cucurbita pepo peel extract (CPE) was used for rapid AgNP formation under natural sunlight using single-step (A-Sun) and dropwise (B-Sun) addition strategies. The characteristic localized surface plasmon resonance (LSPR) band developed near 445–450 nm within 5 min, while corresponding dark controls showed negligible nanoparticle formation over the same period. Both dispersions retained their characteristic LSPR response during six months of optical monitoring. Steady-state photoluminescence (PL) measurements at excitation wavelengths of 300–350 nm and excitation–emission matrix (EEM) fluorescence mapping revealed lower recorded fluorescence intensities in the order CPE > A-Sun > B-Sun, with the principal emission region remaining broadly preserved near 435–440 nm. These observations provide complementary fluorescence fingerprints of the investigated preparations; however, inner-filter effects and light scattering may contribute to the measured attenuation, preventing its exclusive assignment to molecular quenching. FTIR revealed changes in oxygen-containing functional-group vibrations, while TEM showed predominantly spherical to quasi-spherical AgNPs, with mean particle diameters of 11.88 ± 3.60 nm for A-Sun and 9.77 ± 3.43 nm for B-Sun. The resulting dispersions also exhibited antibacterial activity against the six investigated bacterial strains. Overall, integrating PL and EEM with conventional characterization provides additional information on fluorescence changes accompanying sunlight-assisted AgNP formation without directly establishing the individual phytochemical reducing species, electron-transfer steps, or molecular surface-capping mechanisms.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Physics, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdul Aziz University, Al-Kharj 11942, Saudi Arabia",
    "Department of Physics, College of Science, Qassim University, Buraydah, Saudi Arabia",
    "Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, P.O. Box 173, Al-Kharj 11942, Saudi Arabia",
    "Bioenergy Research Unit, Department of Biophysics, Institute for Research and Medical Consultations, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia",
    "Department of Chemistry, Faculty of Applied Sciences, Taiz University, Taiz 6803, Yemen"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 10,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Fatehia S. Alhakami",
      "orcid": "0000-0003-2744-814X"
    },
    {
      "affs": [
        0
      ],
      "name": "Ashjan M. Alharbi"
    },
    {
      "affs": [
        1
      ],
      "name": "Aliaa Alrashidi",
      "orcid": "0009-0006-7317-3529"
    },
    {
      "affs": [
        0
      ],
      "name": "Mohammed S. Alotaibi",
      "orcid": "0000-0002-5355-7684"
    },
    {
      "affs": [
        2
      ],
      "name": "Ehssan Moglad"
    },
    {
      "affs": [
        2
      ],
      "name": "Nourah A. Albarrak"
    },
    {
      "affs": [
        2
      ],
      "name": "Afnan A. Alamri"
    },
    {
      "affs": [
        3
      ],
      "name": "Emre Cevik",
      "orcid": "0000-0003-2075-7361"
    },
    {
      "affs": [
        4
      ],
      "name": "Amani M. Alansi",
      "orcid": "0009-0008-3806-9667"
    },
    {
      "affs": [
        0
      ],
      "name": "Talal F. Qahtan",
      "orcid": "0000-0003-3393-075X"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ewm4qypr2eymy.bib",
  "cited_by": 0,
  "doi": "10.3390/nano16211387",
  "fulltext_url": null,
  "id": "ewm4qypr2eymy",
  "issns": [
    "2079-4991"
  ],
  "landing_url": "https://www.mdpi.com/2079-4991/16/21/1387",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [],
  "openalex": null,
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-29",
  "publisher": "MDPI AG",
  "ris": "https://research.draconitic.com/paper/ewm4qypr2eymy.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:45Z",
      "native_id": "10.3390/nano16211387",
      "source": "crossref",
      "url": "https://www.mdpi.com/2079-4991/16/21/1387"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "issn:2079-4991",
      "subfield": "materials-polymers"
    }
  ],
  "title": "Steady-State Fluorescence and Excitation–Emission Matrix Analysis of Sunlight-Assisted Silver Nanoparticle Formation Using Cucurbita pepo Peel Extract",
  "title_text": "Steady-State Fluorescence and Excitation–Emission Matrix Analysis of Sunlight-Assisted Silver Nanoparticle Formation Using Cucurbita pepo Peel Extract",
  "type": "peer-reviewed",
  "updated_at": "2026-10-31T00:20:50Z",
  "url": "https://research.draconitic.com/paper/ewm4qypr2eymy",
  "venue": "Nanomaterials",
  "versions": []
}