Achieving high specific detectivity ( D * ) in the shortwave infrared (SWIR) region remains challenging for organic photodetectors (OPDs) due to the limited photoelectric conversion efficiency and high dark current density ( J d ). Herein, we present a novel design strategy involving the extended conjugation of central unit to develop non‐fullerene acceptors (NFAs) with an exceptionally low bandgap ( E g opt ) of 0.69 eV. Single crystal X‐ray diffraction analysis reveals that QXIC‐4F exhibits a simultaneous enhancement in quinoidal resonance and diversified intermolecular stacking, resulting in redshifted absorption beyond 1200 nm, improved carrier mobility, reduced non‐radiative recombination, and lower trap density. As a result, OPDs based on QXIC‐4F achieve a high D * exceeding 10 14 Jones at 1040 nm under 0 V bias, significantly outperforming commercial silicon (Si)‐based detectors. Notably, a flexible 15 mm × 15 mm photoplethysmography (PPG) sensor and 256 × 256 organic photodiode image arrays (OPDIA) with 50 µm × 50 µm pixel pitch are successfully fabricated, demonstrating accurate heart rate monitoring and high‐quality SWIR imaging at room temperature.

Achieving high specific detectivity (D *) in the shortwave infrared (SWIR) region remains challenging for organic photodetectors (OPDs) due to the limited photoelectric conversion efficiency and high dark current density (J d). Herein, we present a novel design strategy involving the extended conjugation of central unit to develop non-fullerene acceptors (NFAs) with an exceptionally low bandgap (E g opt) of 0.69 eV. Single crystal X-ray diffraction analysis reveals that QXIC-4F exhibits a simultaneous enhancement in quinoidal resonance and diversified intermolecular stacking, resulting in redshifted absorption beyond 1200 nm, improved carrier mobility, reduced non-radiative recombination, and lower trap density. As a result, OPDs based on QXIC-4F achieve a high D * exceeding 1014 Jones at 1040 nm under 0 V bias, significantly outperforming commercial silicon (Si)-based detectors. Notably, a flexible 15 mm & times; 15 mm photoplethysmography (PPG) sensor and 256 & times; 256 organic photodiode image arrays (OPDIA) with 50 & micro;m & times; 50 & micro;m pixel pitch are successfully fabricated, demonstrating accurate heart rate monitoring and high-quality SWIR imaging at room temperature.

To achieve the commercialization of organic solar cells (OSCs), it is crucial not only to enhance power conversion efficiency (PCE) but also to improve device stability through rational molecular design. Recently emerging giant molecular acceptor (GMA) materials offer various advantages, such as precise chemical structure, high molecular weight (beneficial to film stability under several external stress), and impressive device efficiency, making them a promising candidate. Here, we report a dendritic hexamer acceptor developed through a branch-connecting strategy, which overcomes the molecular weight bottleneck of GMAs and achieves a high production yield over 58

Photomultiplication‐type organic photodetectors (PM‐OPDs) are highly effective for detecting weak optical signals; however, achieving a balance between high gain, broad spectral sensitivity, fast response, and low operating voltage remains a significant challenge. In this study, a solution‐processed approach utilizing tailored non‐fullerene acceptors (NFAs) is presented to enhance electron trapping and enable efficient photomultiplication. Two NFAs, BFDO‐Eh‐4F and BPDO‐Eh‐4F, with distinct LUMO levels, are synthesized and incorporated as dopants. Devices incorporating BFDO‐Eh‐4F demonstrated an exceptional external quantum efficiency (EQE) of 2500% at a 2 V bias and a rapid response time of 420 µs, attributed to its deeper LUMO level that facilitates efficient electron trapping. Conversely, BPDO‐Eh‐4F‐based devices operated in photovoltaic (PV) mode due to weaker electron trapping arising from its shallower LUMO level, achieving low dark current and a high specific detectivity ( D *) of 4.5 × 10¹ 2 Jones. These findings elucidate the role of unbalanced charge transport between holes and electrons in enhancing PM‐OPD performance and highlight the critical influence of LUMO level offsets in optimizing electron trapping. The complementary advantages of these devices position them as promising candidates for applications in imaging, optical communication and biosensing, providing a clear pathway for the development of next‐generation OPDs with balanced performance.

Photomultiplication-type organic photodetectors (PM-OPDs) provide for signal amplification, ideal for detecting faint light, and simplifying detection systems. However, current designs often suffer from slow response speed and elevated dark current. Conversely, photovoltaic-type organic photodetectors (PV-OPDs) provide fast response and high specific detectivity (D*) but have limited photoresponse. This study presents the synthesis and incorporation of a non-fullerene acceptor, BFDO-4F, into the active layer to introduce trap states for capturing photogenerated electrons. The resulting device exhibits dual-mode characteristic and is bias-switchable between PV and PM-modes. In PV-mode, the OPDs achieve high D* of 1.92 × 10¹2 Jones and a response time of 2.83/4.43 µs. In PM-mode, the OPDs exhibit exceptional external quantum efficiency (EQE) up to 3484% and a D* of up to 1.13 × 10¹2 Jones. An on-chip self-powered module with PV-mode pixels driving a PM-mode pixel is demonstrated, yielding a photocurrent approximately five times higher than the reference device. This approach paves the way for developing multifunctional bias-switchable dual-mode on-chip OPDs, suitable for various applications.

Solution-printable processing represents a significant advantage for organic solar cells (OSCs), and the development of printable top electrodes is critical to achieve fully solution-processed organic photovoltaics. Currently, conventional solution-processed top electrodes often face challenges, such as damage to the underlying structure or poor interfacial contact. For the cathode, it is more appropriate to use n-type conducting materials with a low work function (WF). In this work, the combined n-type conductive polymer poly(3,7-dihydrobenzo[1,2-b:4,5-b']difuran-2,6-dione):poly(2-ethyl-2-oxazoline) (PBFDO:PEOx) is used as a top electrode in OSCs via transfer printing, enabling a robust, nondestructive contact between the printed top electrode and the interfacial layer. Due to its high conductivity, suitable WF, and protective role on the underlying structure, the introduced PBFDO:PEOx electrode promotes charge transfer and extraction while reducing nonradiative charge recombination and energy loss. As a result, OSCs based on PBFDO:PEOx/AgNWs printed top electrodes ultimately achieve a power conversion efficiency (PCE) of 14.2%, which is one of the highest PCE values among fully solution-processed OSCs without mirrors. Furthermore, the devices with PBFDO:PEOx electrodes exhibit an infrared blocking efficiency of over 80%, providing both excellent power generation and thermal insulation properties. This work presents a novel approach to the fabrication of printable top electrodes, providing a promising route for the advancement of fully solution-printed electronic devices.

Abstract To achieve the commercialization of organic solar cells (OSCs), it is crucial not only to enhance power conversion efficiency (PCE) but also to improve device stability through rational molecular design. Recently emerging giant molecular acceptor (GMA) materials offer various advantages, such as precise chemical structure, high molecular weight (beneficial to film stability under several external stress), and impressive device efficiency, making them a promising candidate. Here, we report a dendritic hexamer acceptor developed through a branch-connecting strategy, which overcomes the molecular weight bottleneck of GMAs and achieves a high production yield over 58%. The dendritic acceptor Six-IC exhibits modulated crystallinity and miscibility with the donor, thus better morphology performance compared to its monomer, DTC8. Its charge transport ability is further enhanced by additional channels between the armed units. Consequently, the binary OSCs based on D18:Six-IC achieves a cutting-edge efficiency of 19.4% for high-molecular weight acceptor based systems, as well as decent device stability and film ductility. This work reports high-performance OSCs based on dendritic molecule acceptor with a molecular weight exceeding 10000 g/mol and shares the understanding for designing comprehensively high-performing acceptor materials.

Short-wavelength infrared organic photodetectors (SWIR OPDs) have great potential for applications in health monitoring, night vision, optical communication, and image sensing. However, the development of SWIR OPDs is limited by challenges in achieving high responsivity (R) and detectivity (D*) due to the exponentially increased nonradiative recombination rate when decreasing the bandgap of conjugated polymers or molecules. In this study, we designed and synthesized a series of donor-acceptor (D-A) type ultralow bandgap (≤0.85 eV) polymers containing [1,2,5]thiadiazolo[3,4-g]quinoxaline (TQ) units as the A unit and selenophene units as the D unit, respectively. The solubility, molecular stacking, charge transport properties, and film morphology of the polymers were finely tuned by varying the side chain lengths on the substituted phenyl groups of TQ units. It was found that the polymer PTQOD with 2-octyldodecyl alkyl chains has lower nonradiative recombination losses and lower trap state density. After device optimization, the PTQOD-based device achieved higher R and lower dark current density (Jd), resulting in a D* of 1.06 × 1010 Jones at 1300 nm under 0 V bias, representing the highest value for OPDs using TQ-based polymers. This work highlights the importance of optimizing the alkyl chains of ultralow-band gap polymer donor materials and provides a promising approach for developing highly sensitive SWIR OPDs.

We tackle the problem of identifying whether a variable is the cause of a specified target using observational data. State-of-the-art causal learning algorithms that handle latent variables typically rely on identifying the global causal structure, often represented as a partial ancestral graph (PAG), to infer causal relationships. Although effective, these approaches are often redundant and computationally expensive when the focus is limited to a specific causal relationship. In this work, we introduce novel local characterizations that are necessary and sufficient for various types of causal relationships between two variables, enabling us to bypass the need for global structure learning. Leveraging these local insights, we develop efficient and fully localized algorithms that accurately identify causal relationships from observational data. We theoretically demonstrate the soundness and completeness of our approach. Extensive experiments on benchmark networks and real-world datasets further validate the effectiveness and efficiency of our method.

Skin barrier impairment is critical in the development of atopic dermatitis (AD), increasing vulnerability to external pathogens and disrupting cell metabolism, which leads to inflammatory stress and immune imbalance. In this study, a natural turmeric-derived nanovesicle (TDNV)-laden metal polyphenol hydrogel, termed Fe-HD@TDNV is proposed, to synergistically restore the compromised skin barrier in AD through a dual-repair strategy. The TDNV effectively regulates metabolic activity by upregulating the expression of skin barrier proteins, antioxidant enzymes, and antimicrobial peptides (AMPs) in keratinocytes, thereby reinforcing barrier integrity and combating pathogens. Simultaneously, the Fe-HD hydrogel, cross-linked by Fe3⁺ ions and hyaluronic acid-graft-dopamine (HD), provides superior skin compatibility and establishes a low oxidative stress environment for potentiating the therapeutic efficacy of TDNV. By improving skin barrier conditions, the Fe-HD@TDNV hydrogel exhibited desirable performance in maintaining better skin hydration, reducing epidermal thickness, and decreasing abnormal immune responses in acute skin disruption models and AD models. This work is expected to offer insights into the cross-kingdom regulation between plant-derived nanovesicles and mammals, as well as the design of disease-specific dual-functional repair strategies.

Previous studies have extensively addressed the attribution problem for binary outcome variables. However, in many practical scenarios, the outcome variable is continuous, and simply binarizing it may result in information loss or biased conclusions. To address this issue, we propose a series of posterior causal estimands for retrospectively evaluating multiple correlated causes from a continuous outcome. These estimands include posterior intervention effects, posterior total causal effects, and posterior natural direct effects. Under assumptions of sequential ignorability, monotonicity, and perfect positive rank, we show that the posterior causal estimands of interest are identifiable and present the corresponding identification equations. We also provide a simple but effective estimation procedure and establish asymptotic properties of the proposed estimators. An artificial hypertension example and a real developmental toxicity dataset are employed to illustrate our method.

Exosomes play a pivotal role in intercellular communication, with aberrant changes in their cargo closely associated with the progression of various diseases. However, existing single-exosome analysis technologies lack the throughput required for multi-target and large-cohort screening. In this study, we present a high-throughput microfluidic screening platform based on fluorescence combinatorial encoding, enabling multi-sample and multi-target detection at the single- exosome level. Using synthetic hsa-miR-21-Sp and exosomes derived from human gastric epithelial cell lines and gastric cancer cell lines, our approach demonstrated the capability to simultaneously detect multiple microRNA targets on single exosomes across diverse samples within a single experiment.

Recently, the rapid development of non-fullerene acceptors (NFAs) has laid the foundation for performance improvements in near-infrared (NIR) organic photodetectors (OPDs). However, reducing the bandgap of NFAs to achieve strong absorption in the shorter-wave region usually leads to increased dark current density (Jd) and decreased responsivity (R), severely limiting the detectivity (D*) of NIR-OPDs. To date, it remains challenging to manipulate the Jd of NIR-OPDs through rational structure engineering of NFAs. Herein, three NIR-NFAs, namely bis(2-decyltetradecyl)4,4′-(2′,7′-di-tert-butylspiro[cyclopenta[2,1-b:3,4-b′]dithiophene-4,9′-fluorene]-2,6-diyl)bis(6-(((Z)-1-(dicyanomethylene)-5,6-difluoro-3-oxo-1,3-dihydro-2H-inden-2-ylidene)methyl)thieno[3,4-b]thiophene-2-carboxylate) (TSIC-4F), bis(2-decyltetradecyl)6,6′-(2′,7′-di-tert-butylspiro[cyclopenta[2,1-b:3,4-b′]dithiophene-4,9′-fluorene]-2,6-diyl)bis(4-(((Z)-1-(dicyanomethylene)-5,6-difluoro-3-oxo-1,3-dihydro-2H-inden-2-ylidene)methyl)thieno[3,4-b]thiophene-2-carboxylate) (STIC-4F), and 2,2′-((2Z,2′Z)-(((2′,7′-di-tert-butylspiro[cyclopenta [2,1-b:3,4-b′]dithiophene-4,9′-fluorene]-2,6-diyl)bis(2,3-bis(5-(2-butyloctyl)thiophen-2-yl)thieno[3,4-b]pyrazine-7,5-diyl))bis(metha-neylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (TPIC-4F), were designed using the thieno[3,4-b]thiophene (TT) and thieno[3,4-b]pyrazine (TPy) derivatives as the π-bridge. Owing to the intramolecular S-S and S-N interactions, STIC-4F and TPIC-4F exhibited smaller backbone distortions than TSIC-4F. A significantly red-shifted absorption with a peak at 1015 nm was observed in TPIC-4F film, larger than that (ca. 960 nm) for TSIC-4F and STIC-4F films. Moreover, OPDs operating in a photovoltaic mode were successfully fabricated, and TPIC-4F-based OPDs achieved the lowest Jd of 3.18×10−8 A/cm2 at −0.1 V. Impressively, although TPIC-4F-based OPDs exhibited the lowest R, higher shot-noise-limited specific detectivity (Dsh*) in 1000–1200 nm could be achieved due to its lowest Jd. This study underscored the effectiveness of optimizing the π-bridge structure of NFAs to suppress Jd, ultimately attaining higher Dsh* in the NIR region.

The simultaneous improvement of efficiency and stability of organic solar cells (OSCs) for commercialization remains a challenging task. Herein, we designed asymmetric acceptors DT-C8Cl and DT-C8BTz with functional haloalkyl chains, in which the halogen atoms could induce noncovalent interactions with heteroatoms like O, S, and Se, etc ., thus leading to appropriately manipulated film morphology. Consequently, binary devices based on D18: DT-C8Cl achieved a champion power conversion efficiency (PCE) of 19.40 %. The higher PCE of D18: DT-C8Cl could be attributed to the enhanced π–π stacking, improved charge transport, and reduced recombination losses. In addition, the noncovalent interactions induced by haloalkyl chains could effectively suppress unfavorable morphology evolutions and thereby reduce trap density of states, leading to improved thermal and storage stability. Overall, our findings reveal that the rational design of asymmetric acceptors with functional haloalkyl chains is a novel and powerful strategy for simultaneously enhancing the efficiency and stability of OSCs.

Regulation of excessive inflammation and impaired cell proliferation is crucial for healing diabetic wounds. Although plant-to-mammalian regulation offers effective approaches for chronic wound management, the development of a potent plant-based therapeutic presents challenges. This study aims to validate the efficacy of turmeric-derived nanoparticles (TDNPs) loaded with natural bioactive compounds. TDNPs can alleviate oxidative stress, promote fibroblast proliferation and migration, and reprogram macrophage polarization. Restoration of the fibroblast-macrophage communication network by TDNPs stimulates cellular regeneration, in turn enhancing diabetic wound healing. To address diabetic wound management, TDNPs are loaded in an ultralight-weight, high swelling ratio, breathable aerogel (AG) constructed with cellulose nanofibers and sodium alginate backbones to obtain TDNPs@AG (TAG). TAG features wound shape-customized accessibility, water-adaptable tissue adhesiveness, and capacity for sustained release of TDNPs, exhibiting outstanding performance in facilitating in vivo diabetic wound healing. This study highlights the potential of TDNPs in regenerative medicine and their applicability as a promising solution for wound healing in clinical settings.

To evaluate a single cause of a binary effect, Dawid et al. (2014) defined the probability of causation, while Pearl (2015) defined the probabilities of necessity and sufficiency. For assessing the multiple correlated causes of a binary effect, Lu et al. (2023) defined the posterior causal effects based on post-treatment variables. In many scenarios, outcomes are continuous, simply binarizing them and applying previous methods may result in information loss or biased conclusions. To address this limitation, we propose a series of posterior causal estimands for retrospectively evaluating multiple correlated causes from a continuous effect, including posterior intervention effects, posterior total causal effects, and posterior natural direct effects. Under the assumptions of sequential ignorability, monotonicity, and perfect positive rank, we show that the posterior causal estimands of interest are identifiable and present the corresponding identification equations. We also provide a simple but effective estimation procedure and establish the asymptotic properties of the proposed estimators. An artificial hypertension example and a real developmental toxicity dataset are employed to illustrate our method.

Discovering causal relationships from observational data, particularly in the presence of latent variables, poses a challenging problem. While current local structure learning methods have proven effective and efficient when the focus lies solely on the local relationships of a target variable, they operate under the assumption of causal sufficiency. This assumption implies that all the common causes of the measured variables are observed, leaving no room for latent variables. Such a premise can be easily violated in various real-world applications, resulting in inaccurate structures that may adversely impact downstream tasks. In light of this, our paper delves into the primary investigation of locally identifying potential parents and children of a target from observational data that may include latent variables. Specifically, we harness the causal information from m-separation and V-structures to derive theoretical consistency results, effectively bridging the gap between global and local structure learning. Together with the newly developed stop rules, we present a principled method for determining whether a variable is a direct cause or effect of a target. Further, we theoretically demonstrate the correctness of our approach under the standard causal Markov and faithfulness conditions, with infinite samples. Experimental results on both synthetic and real-world data validate the effectiveness and efficiency of our approach.

Open-shell conjugated polymers with a high intrinsic conductivity and high-spin ground state hold considerable promise for applications in organic electronics and spintronics. Herein, two novel acceptor-acceptor (A–A) conjugated polymers based on a highly electron-deficient quinoidal benzodifurandione unit have been developed, namely DPP-BFDO-Th and DPP-BFDO. The incorporation of the quinoidal moiety into the polymers backbones enables deeply aligned lower-lying lowest unoccupied molecular orbital (LUMO) levels of below −4.0 eV. Notably, DPP-BFDO exhibits an exceptionally low LUMO (−4.63 eV) and a high-spin ground state characterized by strong diradical characters. Moreover, a self-doping through intermolecular charge-transfer is observed for DPP-BFDO, as evidenced by X-ray photoelectron spectroscopy (XPS) studies. The high carrier concentration in combination with a planar and linear conjugated backbone yields a remarkable electrical conductivity ( σ ) of 1.04 S cm −1 in the “undoped” native form, ranking among the highest values reported for n-type radical-based conjugated polymers. When employed as an n-type thermoelectric material, DPP-BFDO achieves a power factor of 12.59 μW m −1  K −2 . Furthermore, upon n-doping, the σ could be improved to 65.68 S cm −1 . This study underscores the great potential of electron-deficient quinoidal units in constructing dopant-free n-type conductive polymers with a high-spin ground state and exceptional intrinsic conductivity.

INTRODUCTION:Simultaneous detection of proteins and mRNA within a single extracellular vesicle (EV) enables comprehensive analysis of specific EVs subpopulations, significantly advancing cancer diagnostics. However, developing a sensitive and user-friendly approach for simultaneously detecting multidimensional biomarkers in single EV is still challenging. OBJECTIVES:To facilitate the analysis of multidimensional biomarkers in EVs and boost its clinical application, we present a versatile droplet digital system facilitating the concurrent detection of membrane proteins and mRNA at the single EV level with high sensitivity and specificity. METHODS:The antibody-DNA conjugates were firstly prepared for EVs protein biomarkers recognition and signal transformation. Coupling with the assembled triplex droplet digital PCR system, a versatile droplet digital analysis assay for simultaneous detection of membrane protein and mRNA at a single EV level was developed. RESULTS:Our new droplet digital system displayed high sensitivity and specificity. Additionally, its clinical application was validated in a breast cancer cohort. As expected, this assay has demonstrated superior performance in distinguishing breast cancer from healthy individuals and benign controls through combined detection of EVs protein and mRNA markers compared to any single kind marker detections, especially for patients with breast cancer at early stage (AUC=0.9229). CONCLUSION:Consequently, this study proposes a promising strategy for accurately identifying and analyzing specific EV subgroups through the co-detection of proteins and mRNA at the single EV level, holding significant potential for future clinical applications.

The performance of organic photodetectors (OPDs) sensitive to the short-wavelength infrared (SWIR) light lags behind commercial indium gallium arsenide (InGaAs) photodetectors primarily due to the scarcity of organic semiconductors with efficient photoelectric responses exceeding 1.3 µm. Limited by the Energy-gap law, ultralow-bandgap organic semiconductors usually suffer from severe non-radiative transitions, resulting in low external quantum efficiency (EQE). Herein, a difluoro-substituted quinoid terminal group (QC-2F) with exceptionally strong electron-negativity is developed for constructing a new non-fullerene acceptor (NFA), Y-QC4F with an ultralow bandgap of 0.83 eV. This subtle structural modification significantly enhances intermolecular packing order and density, enabling an absorption onset up to 1.5 µm while suppressing non-radiation recombination in Y-QC4F films. SWIR OPDs based on Y-QC4F achieve an impressive detectivity (D*) over 1011 Jones from 0.4 to 1.5 µm under 0 V bias, with a maximum of 1.68 × 1012 Jones at 1.16 µm. Furthermore, the resulting OPDs demonstrate competitive performance with commercial photodetectors for high-quality SWIR imaging even under 1.4 µm irradiation.