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Cited by 25Luminescence and Fluorescent MaterialsMolecular Sensors and Ion DetectionPhotochemistry and Electron Transfer Studies

Alleviating NIR-II emission quenching in ring-fused fluorophore via manipulating dimer populations for superior fluorescence imaging

Open access
Miao, Xiaofei, Jia, Mingxuan, Weng, Xianwei, Zhang, Jie, Pan, Yonghui, Zhao, Hui, Yu, Zhongzheng, Fan, Quli +1 more·2025·Light: Science & Applications
DOI 10.1038/s41377-025-01787-0PMC PMC11880303
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Abstract

Emission quenching resulting from fluorophore aggregation has long been a significant challenge in optimizing emission-based technologies, such as fluorescence imaging and optoelectronic devices. Alleviating this quenching in aggregates is crucial, yet progress is impeded by the limited understanding of the nature and impact of aggregates on emission. Here, we elucidate the critical role of dimeric aggregate (dimer) in alleviating second near-infrared (NIR-II, 900-1700 nm) emission quenching from ring-fused fluorophore 4F for superior fluorescence imaging. Spectral decomposition and molecular dynamics simulations demonstrate the predominance of dimer populations in 4F aggregates. Notably, dimers exhibit significantly weaker emission but intense intermolecular nonradiative ( inter NR) decay compared to monomers, as demonstrated by ultrafast spectra and quantum calculation. Therefore, the predominant population of dimers with weak emission and pronounced inter NR feature underlies the emission quenching in 4F aggregates. This discovery guides the preparation of ultrabright NIR-II 4F nanofluorophore (4F NP3s) by decreasing dimer populations, which show 5-fold greater NIR-II brightness than indocyanine green, enabling superior resolution in visualizing blood vessels. This work offers valuable insights into aggregation-caused quenching, with broad implications extending far beyond NIR-II fluorescence imaging.

AI snapshot

Written from the paper’s full text.

TL;DR

This study shows that dimeric aggregates dominate in nanoparticles of the ring-fused NIR-II fluorophore 4F and drive emission quenching through weak dimer emission and intense intermolecular nonradiative decay. Reducing the dimer population yields ultrabright 4F NP3s with 7.1 × 10³ M⁻¹ cm⁻¹ NIR-II brightness, enabling high-resolution vascular and tumor imaging in mice.

Key findings

  • In 4F NP1s, spectral decomposition assigns monomer emission at ~940 nm and dimer emission at ~1050 nm, with dimers predominating (64.3% vs. 35.7% monomers); ΦPL drops from 17.1% for 4F in THF to 2.6% in 4F NP1s, and brightness falls from 1.09 × 10⁴ to 1.79 × 10³ M⁻¹ cm⁻¹.
  • Femtosecond transient absorption shows 4F NP1s have a 0.43 ps component assigned to dimer intermolecular nonradiative decay, a 7.73 ps dimer emission component, and a 179 ps monomer fluorescence component, versus 4.6 and 134 ps components for 4F in THF; dimer radiative decay is ~30 times faster than monomer decay (7.7 vs. 179 ps).
  • Reducing dimer population produces 4F NP3s with ΦPL increased from 2.6% to 7.5%, ε at 808 nm increased from 6.8 × 10⁴ to 9.5 × 10⁴ M⁻¹ cm⁻¹, and brightness of 7.1 × 10³ M⁻¹ cm⁻¹, about 4 times that of 4F NP1s and ~5 times that of ICG (1560 M⁻¹ cm⁻¹).
  • In vivo, 4F NP3s under 1500 nm LP gave FWHM of 0.25 mm and SBR of 4.04, compared with 0.30 mm/2.75 at 1300 nm LP and 0.49 mm/1.71 at 980 nm LP; tumor signal peaked at 24 h and remained detectable at 36 h, with accumulation mainly in liver and spleen and no significant H&E organ damage.

Methods

  • 4F was synthesized as a ring-fused donor–acceptor fluorophore and encapsulated in Pluronic F-127 to form water-soluble nanoparticles at 1, 0.1, and 0.01 mg mL⁻¹, yielding 4F NP1s, NP2s, and NP3s; nanoparticles were characterized by DLS, TEM, zeta potential, and stability tests.
  • Optical and mechanistic analyses included absorption/PL spectroscopy, ΦPL determination relative to IR-26 (0.5%), Gaussian spectral decomposition, molecular dynamics simulations, quantum chemical calculations, femtosecond transient absorption, and femtosecond transient fluorescence spectroscopy.
  • In vivo studies used Balb/c mice for whole-body vascular imaging after tail-vein injection of 4F NP3s (200 μL, 1 mg mL⁻¹) with 980, 1300, and 1500 nm LP filters, and BALB/c nude mice bearing 143B osteosarcoma for tumor imaging from 0 to 48 h, plus biodistribution and H&E staining.

Limitations

  • The paper states that femtosecond transient fluorescence spectroscopy could not measure fluorescence lifetimes for 4F NP2s, 4F NP1s, and 4F because of its detection limit (~300 ps).
  • The paper notes that the clinical and translational path is “undeniably complex,” despite arguing that 4F NP3s satisfy brightness, photostability, and biosafety requirements.
  • Evident from the text: in vivo validation is limited to mouse models, and the reported dimer-population percentages are not fully internally consistent (4F NP1s are stated as 64.3% dimers, while 4F NP3s are later described as reduced from 73.5% to 64.3%), so the quantitative dimer fractions should be interpreted cautiously.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1038/s41377-025-01787-0

Cites

45 of 45 references verified0 citation errors · 0 not checkable

Statistics

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Claims the paper makes

0 of 17 cited sources checked · 0 supported · 0 flagged

  • Findingcitation

    Femtosecond transient absorption spectra provide experimental evidence of weak emission and intense intermolecular nonradiative decay from dimers in 4F NP1s.

    “Femtosecond transient absorption (fs-TA) spectra provided experimental evidence of the weak emission and intense interNR decay from dimers in 4F NP1s37,38.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [37] Maiuri, M., Garavelli, M. & Cerullo, G. Ultrafast spectroscopy: state of the art and open challenges. J. Am. Chem. Soc. 142, 3–15 (2020). source

      Not checked in the free run.

    • cites [38] Hu, W. B., Prasad, P. N. & Huang, W. Manipulating the dynamics of dark excited states in organic materials for phototheranostics. Acc. Chem. Res. 54, 697–706 (2021). source

      Not checked in the free run.

  • Findingown data

    4F in tetrahydrofuran exhibits intense NIR-II emission with photoluminescence quantum yield up to 17.1%.

    “and intense NIR-II emission with ultrahigh ΦPL of up to 17.1% (reference: IR-26, ΦPL = 0.5%, Fig. 2b, Fig. S10).”
    Quote in the paperSubstantial claim
  • Findingown data

    Spectral decomposition reveals a reduced dimer population from 73.5% to 64.3% in 4F NP3s.

    “Spectral decomposition revealed a reduced dimer population from 73.5% to 64.3% in 4F NP3s (Fig. 4a), consistent with molecular dynamics simulations that showed a reduced proportion of dimers as the decrease in 4F concentration (Fig. S23).”
    Quote in the paperSubstantial claim
  • Findingown data

    The fluorescence brightness of 4F NP1s is decreased by an order of magnitude compared with unimolecular 4F in tetrahydrofuran (1.79 × 10^3 M−1 cm−1 vs. 1.09 × 10^4 M−1 cm−1).

    “Correspondingly, the fluorescence brightness of 4F NP1s decreased by an order of magnitude compared to unimolecular 4F in THF (1.79 × 103 M−1 cm−1 vs. 1.09 × 104 M−1cm−1)”
    Quote in the paperSubstantial claim
  • Findingown data

    4F nanoparticles exhibit superior photostability compared with indocyanine green.

    “Moreover, 4F NPs exhibited superior photostability compared to ICG (Fig. S21).”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim. 3
  • May combine two claims. 41
  • The quote only partly states this claim. 2

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    4F NP2s (0.1 mg mL−1) and 4F NP3s (0.01 mg mL−1) with lower doping concentration exhibit slightly smaller hydrodynamic diameters of 40 nm and 30 nm, respectively, compared with 4F NP1s (1 mg mL−1).

    “The resulting 4F NP2s (4F: 0.1 mg mL−1) and 4F NP3s (4F: 0.01 mg mL−1) with lower doping concentration exhibit slightly smaller hydrodynamic diameters of 40 nm and 30 nm (Fig. S15), respectively, compared to 4F NP1s (4F: 1 mg mL−1).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Kinetic curves within the ground-state bleaching region around 765 nm reveal three components with time constants of 0.43, 7.73, and 179 ps for 4F NP1s, compared with two components of 4.6 and 134 ps for 4F in tetrahydrofuran.

    “The representative kinetic curves within the GSB region around 765 nm reveal three components with time constants of 0.43, 7.73, and 179 ps for 4F NP1s, compared to two components of 4.6 and 134 ps for 4F in THF (Fig. 3c, Table. S5).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    4F NP1s show a significant decrease in fluorescence, with photoluminescence quantum yield decreasing from 17.1% to 2.6%.

    “In contrast, 4F NP1s show a significant decrease in fluorescence, with ΦPL dramatically decreasing from 17.1% to 2.6% (Figs. 2b, S11, Table S3).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    4F NP2s display an absorption spectrum similar to that of 4F NP1s, with distinct monomer and dimer peaks at 760 nm and 840 nm, respectively.

    “4F NP2s displayed an absorption spectrum similar to that of 4F NP1s, with distinct monomer and dimer peaks at 760 nm and 840 nm (Fig. 4a), respectively.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    4F NP1s present accelerated excited-state decay compared with 4F in tetrahydrofuran, consistent with reduced emission.

    “As shown in Fig. 3a, b, the fs-TA mapping of 4F and 4F NP1s exhibits prominent ground state bleaching (GSB) signals around 750 nm, where 4F NP1s present accelerated excited state decay compared to 4F in THF, consistent with its reduced emission.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    As the water fraction increases, the aggregation-associated emission around 1050 nm becomes more pronounced while the overall photoluminescence intensity of 4F gradually decreases.

    “As the fw continued to increase, the aggregation-associated emission around 1050 nm became more pronounced, while the overall PL intensity of 4F gradually decreased (Figs. 2d, S16).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    4F nanoparticles maintain a zeta potential of approximately −15 mV and show negligible changes in size over 15 days of storage, indicating good colloidal stability.

    “These nanoparticles maintain a zeta potential of approximately −15 mV (Fig. S19) and show negligible changes in size over 15 days of storage (Fig. S20), indicating good colloidal stability41,42.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [41] Gu, Y. et al. Chlorination-mediated π-π stacking enhances the photodynamic properties of a NIR-II emitting photosensitizer with extended conjugation. Angew. Chem. Int. Ed. 62, e202303476 (2023). source

      Not checked in the free run.

    • cites [42] Li, D. et al. Photo-triggered cascade therapy: a NIR-II AIE luminogen collaborating with nitric oxide facilitates efficient collagen depletion for boosting pancreatic cancer phototheranostics. Adv. Mater. 36, 2306476 (2024). source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    In 4F NP1s, the weight of dimers significantly surpasses that of monomers (64.3% vs. 35.7%), indicating a predominant population of dimers.

    “Notably, the weight of dimers significantly surpasses that of monomers (64.3% vs. 35.7%) in 4F NP1s, indicating a predominant population of dimers within 4F NP1s (Fig. 2h).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The accelerated radiative decay of dimers (7.7 ps) occurs at a rate nearly 30 times faster than that of monomers (179 ps), suggesting a deactivation preference in radiative pathways for dimers over monomers.

    “In addition, the accelerated radiative decay of dimers (7.7 ps), occurring at a rate nearly 30 times faster than that of monomers (179 ps), also suggests a deactivation preference in radiative pathways for dimers over monomers.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Compared with unimolecular 4F in tetrahydrofuran, 4F NP1s exhibit a pronounced redshift in absorption maximum and an increased molar extinction coefficient at 808 nm of 6.8 × 10^4 M−1 cm−1.

    “Compared to unimolecular 4 F in THF, 4F NP1s exhibited a pronounced redshift in their absorption maximum and an increased ε at 808 nm of 6.8 × 104 M−1 cm−1 (Figs. 2a, S9).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Upon increasing the water fraction to 20%, 4F displays a new red-shifted absorption peak around 850 nm and a photoluminescence peak around 1050 nm, corresponding to the spectral features of 4F NP1s.

    “However, upon increasing the fw to 20%, 4F displayed a new, red-shifted absorption peak around 850 nm and a PL peak around 1050 nm, corresponding well to the spectral features of 4F NP1s (aggregates).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    4F NP1s are uniform nanoparticles with a hydrodynamic diameter of 50 nm.

    “Dynamic light scattering (DLS) and transmission electron microscopy (TEM) confirmed that the resulting nanoparticles were uniform, with a hydrodynamic diameter of 50 nm (Fig. S15).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The NIR-IIb region exhibited the highest signal-to-background ratio of 4.04, surpassing the SBRs of 1.71 and 2.75 for 980 and 1300 nm LP, respectively.

    “Meanwhile, the NIR-IIb region exhibited the highest signal-to-background ratio (SBR) of 4.04, surpassing the SBRs of 1.71 and 2.75 for 980 and 1300 nm LP, respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    4F NP3s demonstrate superior fluorescence brightness of 7.1 × 10^3 M−1 cm−1, nearly maintaining the brightness of unimolecular 4F in tetrahydrofuran (10.9 × 10^3 M−1 cm−1) and being 4-times higher than that of 4F NP1s (1.8 × 10^3 M−1 cm−1).

    “Collectively, 4F NP3s demonstrated superior fluorescence brightness of 7.1 × 103 M−1cm−1 (Fig. 4c), which nearly maintains the brightness of unimolecular 4F in THF (10.9 × 103 M−1cm−1) and is 4-times higher than that of 4F NP1s (1.8 × 103 M−1cm−1).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In osteosarcoma-bearing mice, distinct NIR-II fluorescence signals appeared at the tumor sites after 6 h post-administration, with signal intensity progressively increasing and peaking at 24 h.

    “As shown in Fig. 5c, distinct NIR-II fluorescence signals were observed at the tumor sites after 6 h post-administration, with signal intensity progressively increasing and peaking at 24 hours.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Multiple dimer architectures coexist alongside monomers of 4F within its aggregate, with the dimer population predominating.

    “Our findings reveal the coexistence of multiple dimer architectures alongside monomers of 4F within its aggregate, with dimer population predominating.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Dimers of 4F exhibit significantly weaker emission and more intense intermolecular nonradiative (interNR) decay compared to monomers.

    “Notably, dimers exhibit significantly weaker emission and more intense interNR compared to monomers.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Femtosecond transient fluorescence spectroscopy measures the fluorescence lifetime of 4F NP3s as 435 ps, which aligns well with the long-lived component (496 ps) extracted by femtosecond transient absorption within ground-state bleaching regions.

    “Femtosecond transient fluorescence spectroscopy measured the fluorescence lifetime of 4F NP3s as 435 ps (Fig. 4e), which aligns well with the long-lived component (496 ps) extracted by the fs-TA within GSB regions.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    4F NP3s have an ultrahigh NIR-II brightness of 7125 M−1 cm−1, one of the highest levels of brightness among available NIR-II fluorophores.

    “The ultrahigh NIR-II brightness (7125 M−1 cm−1) represents one of the highest levels of brightness among available NIR-II fluorophores (Table S1, 2), offering unprecedented potential in high-resolution visualization of vital structures such as blood vessels and malignant lesions (Fig. 5a, b).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given

    The 4F molecule features an intramolecular noncovalent S···O interaction that promotes a giant π-conjugation and a rigid molecular structure.

    “The 4F molecule features an intramolecular noncovalent S···O interaction that promotes a giant π-conjugation and a rigid molecular structure.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Small vessels branching around the abdominal vessels were clearly distinguished in the NIR-IIb region, whereas no clear image could be obtained in the conventional NIR-II window.

    “Importantly, small vessels branching around the abdominal vessels were clearly distinguished in the NIR-IIb region, whereas no clear image could be obtained in the conventional NIR-II window (Fig. 5a).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    4F NP3s exhibit long-term colloidal and optical stability.

    “Moreover, their long-term colloidal and optical stability facilitates real-time and dynamic high-resolution imaging (Fig. 5b, Fig. S19–22), which could revolutionize surgical procedures and therapeutic interventions.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The populations of monomer fluorescence increase from 9.6% to 20.2% as the dimer populations decrease, supporting the elevated photoluminescence quantum yield of 4F NP3s.

    “Moreover, the populations of this monomer fluorescence increased from 9.6% to 20.2% as the dimer populations decreased (Table S5), supporting the elevated ΦPL of 4F NP3s.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The molar extinction coefficient is progressively enhanced from 6.8 × 10^4 to 7.2 × 10^4 and 9.5 × 10^4 M−1 cm−1 at 808 nm as aggregation decreases, with 4F NP3s exhibiting an ultrahigh molar extinction coefficient relative to unimolecular 4F.

    “Moreover, ε was also progressively enhanced from 6.8 × 104 to 7.2 × 104 and 9.5 × 104 M−1cm−1 at 808 nm as aggregation decreased (Fig. S9), with 4F NP3s exhibiting an ultrahigh ε relative to unimolecular 4F (ε808nm = 6.4 × 104 M−1cm−1).”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    Hematoxylin-eosin staining of the major organs 48 h post-injection showed no significant hydropic damage or necrotic lesions.

    “Furthermore, hematoxylin–eosin (H&E) staining of the major organs showed no significant hydropic damage or necrotic lesions, indicating the good biosafety of 4F NP3s (Fig. S27).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Weak dimer emission, together with nonradiative deactivation priority over monomer, further reduces emission.

    “This weak dimer emission, but having nonradiative deactivation priority over monomer, further reduces emission.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Conjugation extension can improve long-wavelength absorption but often shows ultralow photoluminescence quantum yield due to more pronounced aggregation-caused quenching and molecular motion.

    “In contrast, conjugation extension can improve long-wavelength absorption but often shows ultralow ΦPL due to more pronounced ACQ and molecular motion21.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [21] Su, Y. B. et al. NIR-II bioimaging of small organic molecule. Biomaterials 271, 120717 (2021). source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    The intense long-wavelength absorption and emission of 4F arise from extensive π-conjugation in its fully planar backbone, with negligible torsion (<0.4°) in both S0 and S1 states.

    “The intense long-wavelength absorption and emission arise from the extensive π-conjugation in the fully planar backbone of 4F, with negligible torsion (<0.4˚) in both S0 and S1 states (Fig. 2c, Fig. S12).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The femtosecond component of 0.43 ps observed in 4F NP1s corresponds to intermolecular nonradiative decay from dimers, while the 7.7 ps component is attributed to dimer emission.

    “The femtosecond component of 0.43 ps observed in 4F NP1s corresponds to interNR decay from dimers, while the 7.7 ps component is attributed to dimer emission.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Upon photoexcitation, both monomers and dimers reach the excited state; dimers primarily return to the ground state through ultrafast intermolecular nonradiative decay and, to a lesser extent, through radiative decay.

    “Upon photoexcitation, both monomers and dimers reach the excited state. Dimers primarily return to the ground state through ultrafast interNR and, to a lesser extent, through radiative decay.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The distinctive conformational lock of 4F supports the planar conformation necessary for intense long-wavelength absorption and emission and induces a rigid structure that significantly inhibits nonradiative energy loss through molecular motions.

    “Notably, this distinctive conformational lock not only supports the planar conformation necessary for intense long-wavelength absorption and emission but also induces a rigid structure that significantly inhibits nonradiative energy loss through molecular motions.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    In 4F aggregates, the formation of dimers generates new near-infrared absorption peaks around 840 nm and induces a further redshift of the original monomer absorption peak.

    “In 4F aggregates, the formation of dimers not only generates new near-infrared absorption peaks around 840 nm but also induces a further redshift of the original monomer absorption peak.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The absence of the femtosecond component in diluted tetrahydrofuran solutions rules out structural relaxation and reinforces the assignment of the femtosecond component to dimer.

    “Therefore, the absence of the femtosecond component in these solutions rules out the possibility of structural relaxation, reinforcing the assignment of femtosecond component to dimer.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Ring-fused NIR-II fluorophores undergo severe aggregation-caused quenching, with photoluminescence quantum yield decreasing from 15.1% in the unimolecular state to 2.1% in the aggregated state.

    “However, these ring-fused NIR-II fluorophores also undergo severe ACQ, showing a dramatic decrease in ΦPL from 15.1% in unimolecular state to 2.1% in practical application (aggregated state)31.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [31] Yuan, Y. et al. Molecular programming of NIR-IIb-Emissive semiconducting small molecules for in vivo high-contrast bioimaging beyond 1500 nm. Adv. Mater. 34, 2201263 (2022). source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    Femtosecond transient fluorescence spectroscopy could not measure the fluorescence lifetimes for 4F NP2s, 4F NP1s, and 4F due to its detection limit of approximately 300 ps.

    “Unfortunately, our femtosecond transient fluorescence spectroscopy could not measure the fluorescence lifetimes for 4F NP2s, 4F NP1s, and 4F due to its detection limit (~300 ps).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    The extensive π-conjugation of 4F facilitates both intense absorption and high photoluminescence quantum yield, while its rigid structure minimizes nonradiative energy loss from molecular motions such as conformational dynamics.

    “The extensive π-conjugation facilitates both intense absorption and high ΦPL, while the rigid structure minimizes nonradiative energy loss by molecular motions such as conformational dynamics.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    4F NP3s enable high-resolution imaging of vascular blood vessels and deep-seated osteosarcoma.

    “Building on this finding, reducing the dimer population leads to the development of ultrabright 4F NP3s, which enable high-resolution imaging of vascular blood vessels and deep-seated osteosarcoma.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The osteosarcoma-bearing BALB/c nude mouse model represents deep-seated tumors for the purpose of assessing the clinical imaging potential of 4F NP3s.

  • May combine two claims. The quote only partly states this claim.

    Interpretationown data

    4F NP3s enable high-performance in vivo NIR-II fluorescence imaging with superior signal-to-background ratio and sharp resolution.

    “These findings demonstrate high-performance fluorescence imaging in vivo with superior SBR using 4F NP3s.”
    • Also stated in: § High-performance NIR-II fluorescence imaging in vivo · boosted
      “Overall, 4F NP3s demonstrate high-performance NIR-IIb angiography with sharp resolution and excellent potential as tumor navigation contrasts for phototheranostic applications.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    These phenomena suggest successful regulation of dimer population in alleviating aggregation-caused quenching, thereby improving the NIR-II brightness of 4F aggregates.

    “These phenomena suggest the successful regulation of dimer population in alleviating ACQ, thereby improving the NIR-II brightness of 4F aggregates.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Aggregation-caused quenching typically arises from fluorophore aggregation, which brings molecules into close contact and facilitates nonradiative energy loss via intermolecular interactions.

  • May combine two claims.

    Interpretationreasoning

    Dimers with extended intermolecular distances not only preserve intense long-wavelength absorption but also alleviate the long-standing aggregation-caused quenching issue, offering insights for designing brighter fluorophores beyond NIR-II fluorescence imaging applications.

    “Dimers with extended intermolecular distances not only preserve the intense long-wavelength absorption but also alleviate the long-standing ACQ issue, offering valuable insights for designing brighter fluorophores beyond NIR-II fluorescence imaging applications.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Aggregation-caused quenching typically arises from fluorophore aggregation, which brings molecules into close contact and facilitates nonradiative energy loss via intermolecular interactions.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    All animal studies were performed following the Guide for the Institutional Animal Care and Use Committee and under a protocol approved by the Animal Health and Use Committee of Northwestern Polytechnical University.

    “All the animal studies were performed following the Guide for the Institutional Animal Care and Use Committee and the protocol approved by the Animal Health and Use Committee of Northwestern Polytechnical University.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    4F NP3s have good biosafety, with negligible long-term toxicity.

    “Furthermore, hematoxylin–eosin (H&E) staining of the major organs showed no significant hydropic damage or necrotic lesions, indicating the good biosafety of 4F NP3s (Fig. S27).”
    • Also stated in: § Discussion · hedged
      “Biosafety analyses of 4 F NP3s indicate negligible long-term toxicity, with metabolism primarily via liver (Fig. S26, 27).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    4F NP3s can achieve deep penetration imaging and effectively accumulate in the tumor region through the enhanced permeability and retention (EPR) effect.

    “These results indicate that 4F NP3s can achieve deep penetration imaging and effectively accumulate in the tumor region through the enhanced permeability and retention (EPR) effect.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The intensity of the NIR-II fluorescence signal at the tumor site reflects the amount of 4F NP3s accumulated there.
    • Rests on an assumption: The osteosarcoma-bearing BALB/c nude mouse model represents deep-seated tumors for the purpose of assessing the clinical imaging potential of 4F NP3s.
43 of 43

  • The paper relies on this without support.

    The exact nature and role of aggregates in aggregation-caused quenching remain poorly understood.

    “Unfortunately, the exact nature and role of these aggregates remain poorly understood.”

  • The paper relies on this without support.

    Aggregation-caused quenching typically arises from fluorophore aggregation, which brings molecules into close contact and facilitates nonradiative energy loss via intermolecular interactions.

    “ACQ typically arises from fluorophore aggregation, which brings molecules into close contact, facilitating nonradiative energy loss via intermolecular interactions.”

  • The paper relies on this without support.

    The intensity of the NIR-II fluorescence signal at the tumor site reflects the amount of 4F NP3s accumulated there.

    “These results indicate that 4F NP3s can achieve deep penetration imaging and effectively accumulate in the tumor region through the enhanced permeability and retention (EPR) effect.”

  • The paper relies on this without support.

    The osteosarcoma-bearing BALB/c nude mouse model represents deep-seated tumors for the purpose of assessing the clinical imaging potential of 4F NP3s.

    “4F NP3s further demonstrate its potential in deep-seated tumor imaging using an osteosarcoma-bearing BALB/c nude mouse mode45.”
4 of 4

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • NP3 dimer population matches the previously reported NP1 value

    Major

    The paper describes a reduction to 64.3% dimers in NP3s, but earlier assigns 64.3% dimers to NP1s. As stated, those values do not show a reduction from NP1s to NP3s.

  • Reported decay-rate comparison is nearly 30-fold instead of 23-fold

    Minor

    For decay time constants of 7.7 ps and 179 ps, the rate ratio is 179/7.7 ≈ 23.25, not nearly 30.

    Reported 30 · recomputed 23.246753

  • Angiography filter wavelength differs between sections

    Minor

    The results describe a 1000 nm long-pass filter for the angiography experiment, while the methods specify a 980 nm long-pass filter.

3 of 3

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Authors
Miao, X., Jia, M., Weng, X., Zhang, J., Pan, Y., Zhao, H., Yu, Z., Fan, Q., & Hu, W.
Affiliations
  • Northwestern Polytechnical University (CN)
  • Nanjing University of Posts and Telecommunications (CN)
  • University of Cambridge (GB)
Corresponding author
  • Fan, Quli
  • Hu, Wenbo
ORCID
Venue
Light: Science & Applications
Publisher
Springer Science and Business Media LLC
Published
2025-03-04
Volume
14
Issue
1
Pages
109-109
ISSN
2047-7538 (ISSN-L)
DOI
10.1038/s41377-025-01787-0
PMC
PMC11880303
OpenAlex
W4408133384
Semantic Scholar
fcb5d5828af82ffe7d8e5a83189f0b37f2144c75
Cited by
25
References
45
Citations by year
2026: 14 · 2025: 11
FWCI
5.28
Type
journal article
Language
en
Open access
Licence
Locations
  • Light Science & Applications (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Apollo (University of Cambridge) (submittedVersion, cc-by)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Funders
  • National Natural Science Foundation of China (62288102, 62175201, 52373142)
  • Fundamental Research Funds for the Central Universities
  • the open research fund of State Key Laboratory of Organic Electronics and Information Displays
Topics
  • Physical Sciences › Materials Science › Materials Chemistry › Luminescence and Fluorescent Materials
  • Physical Sciences › Chemistry › Spectroscopy › Molecular Sensors and Ion Detection
  • Physical Sciences › Chemistry › Physical and Theoretical Chemistry › Photochemistry and Electron Transfer Studies
Keywords
NIR-II fluorescence, aggregation-caused quenching, vascular imaging, fluorescence imaging, molecular dynamics simulation, ultrafast spectroscopy

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-08.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-08.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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