Organic hole transport materials for high performance PbS quantum dot solar cells.

We developed a triazatruxene-based hole transport material (HTM), 3Ka-DBT-3Ka, aiming to enhance band alignment and augment charge generation and collection in devices, as an alternative for 1,2-ethanedithiol (EDT). The PbS CQD solar cells employing 3Ka-DBT-3Ka as the HTM achieve a peak efficiency of 11.4%, surpassing devices employing the conventional PbS-EDT HTM (8.9%).

Bioorthogonal Cu Single-atom Nanozyme for Synergistic Nanocatalytic Therapy, Photothermal Therapy, Cuproptosis, and Immunotherapy.

Single-atom nanozymes (SAzymes) with atomically dispersed active sites are potential substitutes for natural enzymes. A systematic study of its multiple functions can in-depth understand SAzymes's nature, which remains elusive. Here, we develop a novel ultrafast synthesis of sputtered SAzymes by in situ bombarding-embedding technique. Using this method, sputtered copper (Cu) SAzymes (CuSA) is developed with unreported unique planar Cu-C3 coordinated configuration. To enhance the tumor-specific targeting, we employ a bioorthogonal approach to engineer CuSA, denoted as CuSACO. CuSACO not only exhibits minimal off-target toxicity but also possesses exceptional ultrahigh catalase-, oxidase-, peroxidase-like multienzyme activities, resulting in reactive oxygen species (ROS) storm generation for effective tumor destruction. Surprisingly, CuSACO can release Cu ions in the presence of glutathione (GSH) to induce cuproptosis, enhancing the tumor treatment efficacy. Notably, CuSACO's remarkable photothermal properties enables precise photothermal therapy (PTT) on tumors. This, combined with nanoenzyme catalytic activities, cuproptosis and immunotherapy, efficiently inhibiting the growth of orthotopic breast tumors and gliomas, and lung metastasis. Our research highlights the potential of CuSACO as an innovative strategy to utilize multiple mechanism to enhance tumor therapeutic efficacy, broadening the exploration and development of enzyme-like behavior and physiological mechanism of action of SAzymes.

Molecular Engineering of Activatable NIR-II Hemicyanine Reporters for Early Diagnosis and Prognostic Assessment of Inflammatory Bowel Disease.

Molecular imaging in the second near-infrared window (NIR-II) provides high-fidelity visualization of biopathological events in deep tissue. However, most NIR-II probes produce "always-on" output and demonstrate poor signal specificity toward biomarkers. Herein, we report a series of hemicyanine reporters (HBCs) with tunable emission to NIR-II window (715-1188 nm) and structurally amenable to constructing activatable probes. Such manipulation of emission wavelengths relies on rational molecular engineering by integrating benz[c,d]indolium, benzo[b]xanthonium, and thiophene moieties to a conventional hemicyanine skeleton. In particular, HBC4 and HBC5 possess bright and record long emission over 1050 nm, enabling improved tissue penetration depth and superior signal to background ratio for intestinal tract mapping than NIR-I fluorophore HC1. An activatable inflammatory reporter (AIR-PE) is further constructed for pH-triggered site-specific release in colon. Due to minimized background interference, oral gavage of AIR-PE allows clear delineation of irritated intestines and assessment of therapeutic responses in a mouse model of inflammatory bowel disease (IBD) through real-time NIRF-II imaging. Benefiting from its high fecal clearance efficiency (>90%), AIR-PE can also detect IBD and evaluate the effectiveness of colitis treatments via in vitro optical fecalysis, which outperforms typical clinical assays including fecal occult blood testing and histological examination. This study thus presents NIR-II molecular scaffolds that are not only applicable to developing versatile activatable probes for early diagnosis and prognostic monitoring of deeply seated diseases but also hold promise for future clinical translations.

Oxygen-independent organic photosensitizer with ultralow-power NIR photoexcitation for tumor-specific photodynamic therapy.

Photodynamic therapy (PDT) is a promising cancer treatment but has limitations due to its dependence on oxygen and high-power-density photoexcitation. Here, we report polymer-based organic photosensitizers (PSs) through rational PS skeleton design and precise side-chain engineering to generate •O2- and •OH under oxygen-free conditions using ultralow-power 808 nm photoexcitation for tumor-specific photodynamic ablation. The designed organic PS skeletons can generate electron-hole pairs to sensitize H2O into •O2- and •OH under oxygen-free conditions with 808 nm photoexcitation, achieving NIR-photoexcited and oxygen-independent •O2- and •OH production. Further, compared with commonly used alkyl side chains, glycol oligomer as the PS side chain mitigates electron-hole recombination and offers more H2O molecules around the electron-hole pairs generated from the hydrophobic PS skeletons, which can yield 4-fold stronger •O2- and •OH production, thus allowing an ultralow-power photoexcitation to yield high PDT effect. Finally, the feasibility of developing activatable PSs for tumor-specific photodynamic therapy in female mice is further demonstrated under 808 nm irradiation with an ultralow-power of 15 mW cm-2. The study not only provides further insights into the PDT mechanism but also offers a general design guideline to develop an oxygen-independent organic PS using ultralow-power NIR photoexcitation for tumor-specific PDT.

Deciphering Oxygen-Independent Augmented Photodynamic Oncotherapy by Facilitating the Separation of Electron-Hole Pairs.

Developing Type-I photosensitizers provides an attractive approach to solve the dilemma of inadequate efficacy of photodynamic therapy (PDT) caused by the inherent oxygen consumption of traditional Type-II PDT and anoxic tumor microenvironment. The challenge for the exploration of Type-I PSs is to facilitate the electron transfer ability of photosensitization molecules for transforming oxygen or H2O to reactive oxygen species (ROS). Herein, we propose an electronic acceptor-triggered photoinduced electron transfer (a-PET) strategy promoting the separation of electron-hole pairs by marriage of two organic semiconducting molecules of a non-fullerene scaffold-based photosensitizer and a perylene diimide that significantly boost the Type-I PDT pathway to produce plentiful ROS, especially, inducing 3.5-fold and 2.5-fold amplification of hydroxyl (OH⋅) and superoxide (O2 -⋅) generation. Systematic mechanism exploration reveals that intermolecular electron transfer and intramolecular charge separation after photoirradiation generate a competent production of radical ion pairs that promote the Type-I PDT process by theoretical calculation and ultrafast femtosecond transient absorption (fs-TA) spectroscopy. By complementary tumor diagnosis with photoacoustic imaging and second near-infrared fluorescence imaging, this as-prepared nanoplatform exhibits fabulous photocytotoxicity in harsh hypoxic conditions and terrific cancer revoked abilities in living mice. We envision that this work will broaden the insight into high-efficiency Type-I PDT for cancer phototheranostics.

Self-amplified activatable nanophotosensitizers for HIF-1α inhibition-enhanced photodynamic therapy.

Activatable photodynamic therapy (PDT) has shown great potential in cancer therapy owing to its high tumor specificity and minimized side effect. However, the relatively low level of biomarkers within tumor tissue rescricts the photosensitizer to get thoroughly activated. In this study, we design a self-amplified activatable nanophotosensitizer (CPPa NP) for enhanced PDT. CPPa NP is prepared by encapsulating a hypoxia-inducible factor 1α (HIF-1α) inhibitor CI-994 with an amphiphilic hydrogen peroxide (H2O2) responsive copolymer PPa-CA-PEG. Upon the addition of H2O2, the thioketal linker within CPPa NP is cleaved, resulting in the simultaneous release of thiol-modified pyropheophorbide a (PPa-SH), cinnamic aldehyde (CA), and CI-994. PPa-SH can be encapsulated by albumin to turn on its photodynamic efficiency, while CI-994 may inhibit the expression of HIF-1α to improve the PDT efficacy. CA is able to deplete glutathione (GSH) and upregulate reactive oxygen species (ROS) within tumor cells, accelerating the dissociation of nanoparticles and disrupting the redox balance of tumor cells. In vitro and in vivo studies showed that CPPa NP can successfully elevate the ROS level within 4T1 cells and has a better anticancer efficacy than PPa NP without CI-994 under laser irradiation. This study thus provides an effective approach to develop self-amplified activatable nanoparticles for enhanced PDT.

Self-amplified activatable nanoprodrugs for enhanced chemodynamic/chemo combination therapy.

Chemodynamic therapy (CDT) has gained increasing attention by virtue of its high tumor specificity and low side effect. However, the low concentration of hydrogen peroxide (H2O2) in the tumor site suppresses the therapeutic efficacy of CDT. To improve the efficacy, introducing other kind of therapeutic modality is a feasible choice. Herein, we develop a self-amplified activatable nanomedicine (PCPTH NP) for chemodynamic/chemo combination therapy. PCPTH NP is composed of a H2O2-activatable amphiphilic prodrug PEG-PCPT and hemin. Upon addition of H2O2, the oxalate linkers within PCPTH NP are cleaved, which makes the simultaneous release of CPT and hemin. The released CPT can not only kill cancer cells but also upregulate the intracellular reactive oxygen species (ROS) level. The elevated ROS level may accelerate the release of drugs and enhance the CDT efficacy. PCPTH NP shows a H2O2concentration dependent release profile, and can effectively catalyze H2O2into hydroxyl radical (·OH) under acidic condition. Compared with PCPT NP without hemin, PCPTH NP has better anticancer efficacy bothin vitroandin vivowith high biosafety. Thus, our study provides an effective approach to improve the CDT efficacy with high tumor specificity.

Size Modulation of Conjugated Polymer Nanoparticles for Improved NIR-II Fluorescence Imaging and Photothermal Therapy.

Near-infrared-II fluorescence imaging (NIR-II FI) has become a powerful imaging technique for disease diagnosis owing to its superiorities, including high sensitivity, high spatial resolution, deep imaging depth, and low background interference. Despite the widespread application of conjugated polymer nanoparticles (CPNs) for NIR-II FI, most of the developed CPNs have quite low NIR-II fluorescence quantum yields based on the energy gap law, which makes high-sensitivity and high-resolution imaging toward deep lesions still a huge challenge. This work proposes a nanoengineering strategy to modulate the size of CPNs aimed at optimizing their NIR-II fluorescence performance for improved NIR-II phototheranostics. By adjusting the initial concentration of the synthesized conjugated polymer, a series of CPNs with different particle sizes are successfully prepared via a nanoprecipitation approach. Results show that the NIR-II fluorescence brightness of CPNs gradually amplifies with decreasing particle size, and the optimal CPNs, NP0.2, demonstrate up to a 2.05-fold fluorescence enhancement compared with the counterpart nanoparticles. With the merits of reliable biocompatibility, high photostability, and efficient light-heat conversion, the optimal NP0.2 has been successfully employed for NIR-II FI-guided photothermal therapy both in vitro and in vivo. Our work highlights an effective strategy of nanoengineering to improve the NIR-II performance of CPNs, advancing the development of NIR-II FI in life sciences.

Reproducible and High-Performance WOLEDs Based on Independent High-Efficiency Triplet Harvesting of Yellow Hot-Exciton ESIPT and Blue TADF Emitters.

Hot exciton organic light-emitting diode (OLED) emitters can balance the high performance of a device and reduce efficiency roll-off by fast reverse intersystem crossing from high-lying triplets (hRISC). In this study, an excited-state intramolecular proton transfer (ESIPT) fluorophore of 2-(benzo[d]thiazol-2-yl)-4-(pyren-1-yl)phenol (PyHBT) with the typical characteristic properties of a hot exciton is developed. With high efficiency of utilization of the exciton (91%), its yellow OLED exhibited high external quantum efficiency (EQE) of 5.6%, current efficiency (CE) of 16.8 cd A-1 , and power efficiency (PE) of 17.3 lm W-1 . The performance of the yellow emissive "hot exciton" ESIPT fluorophores is among the highest recorded. Due to the large Stokes shift of the ESIPT emitter, non-energy-transferred high-performance white OLEDs (WOLEDs) are developed, which are reproducible and highly efficient. This is possible because of the independent harvesting of most of the triplets in both complementary-color emitters without the interference of energy transfer. The PyHBT-based WOLEDs exhibit a maximum EQE of 14.3% and CE of 41.1 cd A-1 , which facilitates the high-yield mass production of inexpensive WOLEDs.

A noncovalent backbone planarization strategy increases the NIR-II extinction coefficients for gas/phototheranostic applications.

We propose a noncovalent backbone planarization strategy to fabricate a gas/phototheranostic nanocomposite (B-E-NO NPs) in the near-infrared-II (NIR-II, 1000-1700 nm) window by incorporating noncovalent conformational locks. B-E-NO NPs display a giant NIR-II extinction coefficient, realizing multimodal imaging-guided high-efficiency NIR-II photothermal therapy (η = 45.4%) and thermal-initiated nitric oxide combination therapy.

Recent advances in optical biosensing and imaging of telomerase activity and relevant signal amplification strategies.

Telomerase as a new valuable biomarker for early diagnosis and prognosis evaluation of cancer has attracted much interest in the field of biosensors, cell imaging, and drug screening. In this review, we mainly focus on different optical techniques and various signal amplification strategies for telomerase activity determination. Fluorometric, colorimetry, chemiluminescence, surface-enhanced Raman scattering (SERS), and dual-mode techniques for telomerase sensing and imaging are summarized. Signal amplification strategies include two categories: one is nucleic acid-based amplification, such as rolling circle amplification (RCA), the hybridization chain reaction (HCR), and catalytic hairpin assembly (CHA); the other is nanomaterial-assisted amplification, including metal nanoclusters, quantum dots, transition metal compounds, graphene oxide, and DNA nanomaterials. Challenges and prospects are also discussed to provide new insights for future development of multifunctional strategies and techniques for in situ and in vivo analysis of biomarkers for accurate cancer diagnosis.

A Mitochondria-Targeted NIR-II Molecule Fluorophore for Precise Cancer Phototheranostics.

Subcellular organelle mitochondria are becoming a key player and a driver of cancer. Mitochondrial targeting phototheranostics has attracted increasing attention for precise cancer therapy. However, those phototheranostic systems still face great challenges, including complex and multiple components, light scattering, and insufficient therapeutic efficacy. Herein, a molecular fluorophore IR-TPP-1100 was tactfully designed by molecular engineering for mitochondria-targeted fluorescence imaging-guided phototherapy in the second near-infrared window (NIR-II). IR-TPP-1100 not only exhibited prominent photophysical properties and high photothermal conversion efficiency but also achieved excellent mitochondria-targeting ability. The mitochondria-targeting IR-TPP-1100 enabled NIR-II fluorescence and photoacoustic dual-modality imaging of mitochondria at the organism level. Moreover, it integrated photothermal and photodynamic therapy, obtaining remarkable tumor therapeutic efficacy by inducing mitochondrial apoptosis. These results indicate that IR-TPP-1100 has great potential for precise cancer therapy and provides a promising strategy for developing mitochondria-targeting NIR-II phototheranostic agents.

Small-Molecule Phototheranostic Agent with Extended π-Conjugation for Efficient NIR-II Photoacoustic-Imaging-Guided Photothermal Therapy.

Photoacoustic imaging (PAI) and photothermal therapy (PTT) conducted over the near-infrared-II (NIR-II) window offer the benefits of noninvasiveness and deep tissue penetration. This necessitates the development of highly effective therapeutic agents with NIR-II photoresponsivity. Currently, the predominant organic diagnostic agents used in NIR-II PAI-guided PTT are conjugated polymeric materials. However, they exhibit a low in vivo clearance rate and long-term biotoxicity, limiting their clinical translation. In this study, an organic small molecule (CY-1234) with NIR-II absorption and nanoencapsulation (CY-1234 nanoparticles (NPs)) for PAI-guided PTT is reported. Extended π-conjugation is achieved in the molecule by introducing donor-acceptor units at both ends of the molecule. Consequently, CY-1234 exhibits a maximum absorption peak at 1234 nm in tetrahydrofuran. Nanoaggregates of CY-1234 are synthesized via F-127 encapsulation. They exhibit an excellent photothermal conversion efficiency of 76.01% upon NIR-II light irradiation. After intravenous injection of CY-1234 NPs into tumor-bearing mice, strong PA signals and excellent tumor ablation are observed under 1064 nm laser irradiation. This preliminary study can pave the way for the development of small-molecule organic nanoformulations for future clinical applications.

Plasmonic nanoprobes on single AuNTs for evaluating and monitoring the dynamic release of 2D drug carriers.

The use of nanomaterials in drug delivery has gained significant attention in recent years. In this project, we developed a novel localized surface plasmon resonance (LSPR) nanoprobe on single gold triangular nanoplates (AuNTs) for dynamic monitoring of the drug carrier release process. Graphene, as the drug carrier, could be immobilized on the AuNT surface through the π-π* stacking effect. Upon loading or releasing the model drug (doxorubicin, DOX), subtle changes in the local microenvironment's dielectric constant around the AuNTs induced notable red-shifts or blue-shifts in the LSPR scattering spectra of single AuNTs. Furthermore, the spectral shifts led to a continuous enhancement in the red channel of the dark field microscopy (DFM) images during the drug release process in vitro, demonstrating that the drug release system is not susceptible to potential confounding factors. These release kinetics results under different conditions could be well-fitted using the Higuchi desorption model, further proving that this nanoprobe could be employed for evaluating the controlled release ability of 2D nanocarriers. These findings are expected to inspire new ideas and technologies in the preparation of more effective drug carriers, making a significant contribution to the development of drug delivery nanosystems and nanomedicine.

Robust nontarget DNA-triggered catalytic hairpin assembly amplification strategy for the improved sensing of microRNA in complex biological matrices.

A simple but robust fluorescence strategy based on a nontarget DNA-triggered catalytic hairpin assembly (CHA) was constructed to probe microRNA-21 (miR-21). A short ssDNA rather than degradable target miRNA was employed as an initiator. Two molecular beacons needed to assist the CHA process were simplified to avoid unfavorable nonspecific interactions. In the presence of the target, the initiator was released from a partially duplex and triggered the cyclic CHA reaction, resulting in a significantly amplified optical readout. A wide linear range from 0.1 pM to 1000 pM for the sensing of miR-21 in buffer was achieved with a low detection limit of 0.76 pM. Fortunately, this strategy demonstrated an obviously improved performance for miR-21 detection in diluted serum. The fluorescence signals were enhanced remarkably and the sensitivity was further improved to 0.12 pM in 10% serum. The stability for miR-21 quantification and the capability for the analysis of single nucleotide polymorphisms (SNPs) were also improved greatly. More importantly, the biosensor could be applied to image miR-21 in different living tumor cells with high resolution, illustrating its promising potential for the assay of miRNAs in various complex situations for early-stage disease diagnosis and biological studies in cells.

Iron-chelated semiconducting oligomer nanoparticles for NIR-II fluorescence imaging-guided enhanced chemodynamic/photothermal combination therapy.

Chemodynamic therapy (CDT) has attracted increasing attention owing to its high tumor specificity and low number of side effects. However, the low absolute concentration of reactive oxygen species (ROS) within tumor cells restricts the CDT efficacy. Herein, we use dihydroartemisinin (DHA) to enhance the CDT efficacy and combine photothermal therapy (PTT) to further improve the anticancer effect. To achieve such a goal, an iron-containing semiconducting oligomer nanoparticle (DHA@FePSOD) is prepared by loading DHA into a Fe3+-chelated NIR-II fluorescent semiconducting oligomer (FePSOD). The Fe3+ ion within DHA@FePSOD can be reduced to the Fe2+ ion by glutathione (GSH) and subsequently catalyze the decomposition of hydrogen peroxide (H2O2) into the highly toxic hydroxyl radical (˙OH) for CDT. The loaded DHA may be further reduced by Fe2+ and generate a DHA radical to enhance the CDT efficacy. In addition, DHA@FePSOD shows a good photothermal effect and intense NIR-II fluorescence signal under 808 nm laser irradiation. Both in vitro and in vivo studies prove the better anticancer effect of DHA@FePSOD than FePSOD, which is attributed to the loaded DHA. Furthermore, DHA@FePSOD can effectively accumulate into a tumor and delineate the tumor via NIR-II fluorescence imaging. This study thus provides an efficient approach for developing a NIR-II fluorescence imaging-guided enhanced chemodynamic/photothermal combination therapeutic nanoplatform.

Phenylboronic Acid-Modified Near-Infrared Region II Excitation Donor-Acceptor-Donor Molecule for 2-Deoxy-d-Glucose Improved Starvation/Chemo/Photothermal Combination Therapy.

Synergistic chemotherapy and photothermal therapy (PTT) have emerged as a promising anticancer paradigm to achieve expected therapeutic effects while mitigating side effects. However, the chemo/PTT combination therapy suffers from limited penetration depth, thermoresistance performance of tumor cells, and low drug bioavailability. Herein, multifunctional nanoparticles (BTP/DOX/2DG NPs) coloaded with near-infrared region II (NIR-II) light excitation donor-acceptor-donor (D-A-D) small molecules, doxorubicin (DOX), and 2-deoxy-d-glucose (2-DG) are developed for reinforced starvation/chemo/NIR-II PTT combination therapy. The synthesized phenylboronic acid (PBA)-modified water-soluble D-A-D molecule (BBT-TF-PBA) not only exhibits high binding ability to DOX and 2-DG through donor-acceptor coordination interactions PBA-diol bonds but also serves as a photoactive agent for NIR-II fluorescence imaging, NIR-II photoacoustic imaging, and NIR-II PTT. Under the acidic and oxidizing conditions in the tumor microenvironment, donor-acceptor coordination interactions and PBA-diol bond are decomposed, simultaneously releasing DOX and 2-DG from BTP/DOX/2DG NPs to achieve effective chemotherapy and starvation therapy. 2-DG also effectively inhibits the expression of heat shock protein and further enhances NIR-II PTT and chemotherapy efficiency. In vitro and in vivo experiments demonstrate the combination effect of BTP/DOX/2DG NPs for chemotherapy, NIR-II PTT, and starvation therapy.

In Situ Noninvasive Observation of Nitric Oxide Fluctuation in SARS-CoV-2 Infection In Vivo by Organic Near-Infrared-II Fluorescent Molecular Nanoprobes.

The pathogenesis understanding of SARS-CoV-2 infection is crucial to prevent the rampant spread of COVID-19 and its contribution to deterioration in health, even death. Nitric oxide (NO), a crucial molecule involved in signal transduction and cytotoxicity, is a possible key regulator in the occurrence and development of COVID-19. However, understanding the pathogenesis of NO in SARS-CoV-2 infection is still in its infancy due to the lack of suitable in situ monitoring probes of NO fluctuation in the complex SARS-CoV-2 infection environment in deep lung tissues. Herein, we developed an activatable near-infrared-II fluorescent molecular nanoprobe (OSNP) that uncages high-resolution and deep-tissue-penetrating near-infrared-II fluorescence signal in specific response to NO for in situ and noninvasive visualization of NO fluctuation in a SARS-CoV-2 infection mouse model in lung tissues. In vivo visualization revealed that the NO level is a positive relationship with SARS-CoV-2 infection progress. With the assistance of immuno-histochemical analyses, we uncovered the NO-involved pathological mechanism, that being the improved NO level is associated with an increase in inducible NO synthase rather than endothelial NO synthase. Our study not only provides the example of a near-infrared-II fluorescent imaging of NO in SARS-CoV-2 infection but also provides opportunities to uncover tunderlying pathomechanism of NO for SARS-Cov-2 infections.

A diketopyrrolopyrrole-based small molecule with an extended conjugated skeleton and J-aggregation behavior for 808 nm laser triggered phototheranostics.

The development of phototheranostic agents, specifically those based on organic small molecules (OSMs) with long wavelength excitation/emission, is an attractive but challenging project. In this contribution, we designed and synthesized a novel conjugate small molecule with a linear structure, named DPP-OPIC. Water-soluble nanoparticle DPP-OPIC NPs were fabricated. They exhibited strong absorption in the region of 600-1000 nm, which was due to the extended conjugate length of the molecular skeleton and J-aggregation behavior. Under 808 nm laser excitation, DPP-OPIC NPs were capable of producing outstanding near-infrared-II (NIR-II, 900-1700 nm) fluorescence. The photoluminescence quantum yield was determined as 0.58%, which enabled high-resolution in vivo tumor imaging. Additionally, a notable photothermal effect with a high photothermal conversion efficiency (41.5%) was achieved by the irradiation of DPP-OPIC NPs. Hence, DPP-OPIC NPs can be used as superior phototheranostic agents, providing valuable contributions to NIR-II fluorescence imaging and photothermal therapy.

Oligomerization Strategy of D-A-Type Conjugated Molecules for Improved NIR-II Fluorescence Imaging.

Fluorescence imaging (FI) in the second near-infrared (NIR-II) window has emerged as a promising imaging method for cancer diagnosis because of its superior properties such as deep penetration depth and high signal-to-background ratio. Despite the superiorities of organic conjugated nanomaterials for NIR-II FI, the issues of low fluorescence quantum yield, weak metabolic capability, undefined molecular structure for conjugated polymers, weak light-harvesting ability, short emission wavelength, and high synthetic complexity for conjugated small molecules still remain to be concerned. We herein propose an oligomerization strategy by facilely adjusting the oligomerization time to balance the advantages and disadvantages between conjugated polymers and small molecules, obtaining the candidate (CO1, oligomerization time: 1 min) with the optimal NIR-II optical performance. Then the CO1 is further prepared into water-dispersed nanoparticles (CON1) via a nanoprecipitation approach. By virtue of the suitable size, excellent NIR-II optical properties, low toxicity, and strong cell-labeling ability, the CON1 is successfully employed for in vivo NIR-II imaging, permitting the real-time visualization of blood vascular system and tumors with high sensitivity and resolution. This work thus not only provides a personalized organic conjugated nano-agent for NIR-II FI, but also highlights the molecular strategy for the development of organic conjugated systems with optimal performance for bio-imaging.