{
  "abstract": "Self-absorption is fatal in up-conversion ultrafast spectroscopy, severely suppressing the fluorescent signal. To conquer this problem, we implemented a front-face optical configuration in fluorescence up-conversion spectroscopy to accurately record the intrinsic excited-state dynamics of near-infrared II (NIR-II) fluorophores, significantly minimizing the optical path length of sample absorption. Concurrently, the inner filter effect (IFE) was greatly prohibited; i.e., the intrinsic fluorescence evolution can be correctly recorded without self-absorption. By combining this optical geometry with the high temporal resolution of the up-conversion technique, we successfully recorded the ultrafast dynamics of the benchmark organic dye IR1061 and the porphyrinoid S2F-2H+ at 1235 nm, in terms of their decay lifetimes of 31 ± 1 ps and 74 ± 3 ps, respectively. Notably, despite a nearly zero Stokes shift (64 cm-1) and strong spectral overlap of the absorption and emission contours of S2F-2H+, the up-conversion detection using front-face geometry leads to a superb signal-to-noise ratio of ca. 334. This optical configuration provides a promising tool for probing NIR-II fluorescence systems, especially for investigating highly self-absorbing materials and paving the way for the rational design of high-performance NIR-II fluorophores.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu300044, Taiwan.",
    "Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001, University Road, Hsinchu300093, Taiwan."
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Tse-Hua Hsu"
    },
    {
      "affs": [
        0
      ],
      "name": "Hao-Chun Huang"
    },
    {
      "affs": [
        1
      ],
      "name": "Yen-Chang Chen",
      "orcid": "0009-0007-8314-8287"
    },
    {
      "affs": [
        1
      ],
      "name": "Yang-Hsiang Chan",
      "orcid": "0000-0001-6496-2362"
    },
    {
      "affs": [
        0
      ],
      "name": "Li-Kang Chu",
      "orcid": "0000-0001-6080-9598"
    },
    {
      "affs": [
        0
      ],
      "name": "I-Chia Chen",
      "orcid": "0000-0002-5821-6416"
    },
    {
      "affs": [
        0
      ],
      "name": "Bo-Han Wu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fxwgff1m12s9s.bib",
  "cited_by": 0,
  "doi": "10.1021/acs.analchem.6c05839",
  "fulltext_url": "https://europepmc.org/articles/PMC13670891",
  "id": "fxwgff1m12s9s",
  "issns": [
    "0003-2700",
    "1520-6882"
  ],
  "landing_url": "https://europepmc.org/article/MED/42916120",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "1606|Photochemistry and Electron Transfer Studies"
    ]
  ],
  "openalex": "W7213955817",
  "pdf_url": "https://europepmc.org/articles/PMC13670891?pdf=render",
  "pmcid": "PMC13670891",
  "pmid": "42916120",
  "published": "2026-10-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/fxwgff1m12s9s.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:36Z",
      "native_id": "MED:42916120",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42916120"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1606|Photochemistry and Electron Transfer Studies",
      "subfield": "physical"
    }
  ],
  "title": "Circumventing Inner Filter Effects in Ultrafast Near-Infrared II (NIR-II) Up-Conversion Spectroscopy Using Front-Face Optical Configuration.",
  "title_text": "Circumventing Inner Filter Effects in Ultrafast Near-Infrared II (NIR-II) Up-Conversion Spectroscopy Using Front-Face Optical Configuration.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:20:36Z",
  "url": "https://research.draconitic.com/paper/fxwgff1m12s9s",
  "venue": "Analytical chemistry",
  "versions": []
}