{
  "abstract": "Ultrafast electron microscopy (UEM) has enabled real-space visualization of dynamics in inorganic nanomaterials on fundamental timescales, but its application to functional biological nanostructures remains largely unexplored. Here, we use time-resolved UEM and electron energyloss spectroscopy (EELS) to probe the photoinduced electronic response and the light-induced chemical modification of the conductive periplasmic nanofiber network extracted from filamentous cable bacteria. Low-loss EELS reveals a feature at 3.6 eV, assigned to π→π* excitations, that is absent in non-conductive bacterial controls. Upon femtosecond near-infrared excitation (800 nm, 4.8 mJ cm−2), the spectral weights of this π feature and of the collective valence excitation at 23.1 eV decrease by ~10% and ~8%, respectively, within the first ~2 ps and largely recover within a few picoseconds, leaving a small long-lived component. A comparison with the expected photothermal response indicates that this transient is dominated by electronic excitation. Power-dependent core-loss EELS and elemental mapping under quasi-continuous illumination show that cumulative exposure irreversibly depletes nitrogen and oxygen, relatively enriches sp2bonded carbon and causes partial mass loss, while the outline of the nanofiber network is preserved. These results establish time-resolved EELS as a probe of the electronic photoresponse and photostability of biological conductors, and show how transient electronic and cumulative chemical light-induced effects can be distinguished in such systems.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Physics",
    "University of Arizona",
    "Center for Attosecond Science and Technology",
    "Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences",
    "Department of Physics and Astronomy",
    "University of Southern California",
    "Alfred E. Mann Department of Biomedical Engineering",
    "Department of Chemistry",
    "Department of Biological Sciences"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "affs": [
        0,
        1,
        2,
        3
      ],
      "name": "Ligong Zhao"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Mohamed Sennary"
    },
    {
      "affs": [
        4,
        5
      ],
      "name": "Anaísa Coelho"
    },
    {
      "affs": [
        4,
        5
      ],
      "name": "Tingting Yang"
    },
    {
      "affs": [
        4,
        5
      ],
      "name": "Nir Sukenik"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Dina Hussein"
    },
    {
      "affs": [
        6,
        5
      ],
      "name": "Olga E. Eremina"
    },
    {
      "affs": [
        4,
        5,
        7,
        8
      ],
      "name": "Mohamed Y El-Naggar"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Mohammed Th. Hassan",
      "orcid": "0000-0002-9669-534X"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/bt51vrfvcq57f.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15010541/v1",
  "fulltext_url": null,
  "id": "bt51vrfvcq57f",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010541/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",
      "1315|Advanced Electron Microscopy Techniques and Applications"
    ]
  ],
  "openalex": "W7222281648",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15010541/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-15",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/bt51vrfvcq57f.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:24Z",
      "native_id": "10.26434/chemrxiv.15010541",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010541/v1"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "openalex:1315|Advanced Electron Microscopy Techniques and Applications",
      "subfield": "structural-biology"
    }
  ],
  "title": "Imaging of ultrafast electronic and chemical dynamics in biological systems",
  "title_text": "Imaging of ultrafast electronic and chemical dynamics in biological systems",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:24Z",
  "url": "https://research.draconitic.com/paper/bt51vrfvcq57f",
  "venue": "ChemRxiv",
  "versions": []
}