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Polarization‐sensitive infrared photodetectors have vast application prospects in imaging systems and polarization sensors due to the addition of new detection dimensions beyond wavelength and intensity. However, most polarization‐sensitive photodetectors are operated in the visible wavelength range and still encounter challenges of limited responsivity (R) and polarization ratio (PR) under short‐wave infrared illumination. To address these issues, a vertical heterostructure of β‐In2Se3‐on‐Te is reported, achieving high‐performance and polarization‐sensitive imaging sensors in the short‐wave infrared (SWIR) region. The high R (2 A/W at 1310 nm and 0.71 A/W at 1550 nm) and specific detectivity (2.14 × 109 Jones at 1310 nm and 7.3 × 108 at 1550 nm) are obtained, which surpasses most photodetectors using anisotropic 2D material in the infrared range. Considering the strong anisotropic nature of Te nanosheets, the device exhibits notable polarization sensitivity with a PR value of 4.95 under 1310 nm laser irradiation. This work proposes a multifunctional photodetector for the great applications of ASCII code transmission and polarization‐sensitive infrared imaging, offering a new opportunity for versatile angle‐resolved optoelectronics in the infrared communication band. [ABSTRACT FROM AUTHOR]

Saturable absorber is a key component in ultrafast pulsed laser systems, which are pivotal in ultrafast physics, high‐speed communication, etc. 2D materials appear to be superior candidates as saturable absorbers for compact pulsed fiber lasers in recent years due to their wide band response and ease of integration. However, the integration of mode‐locked devices inevitably involves contamination or polymer in the interface between the layered saturable absorber and the fiber, which contributes to a high start‐up threshold for the ultrafast pulsed lasers. This study develops an on‐fiber femtosecond laser with 2D narrow‐gap semiconducting BiCuSeO as a saturable absorber by a fully dry integration process thanks to the controllable growth of freestanding quaternary BiCuSeO nanoflakes. The corresponding thermodynamic growth mechanism is systemically revealed by electron microscopy and bind‐energy calculation. An electrostatic‐force‐assisted transfer method is developed to avoid damage or chemical contamination. The BiCuSeO‐based femtosecond laser shows decent output performance (pulse width, signal‐noise ratio and repetition rate are 395 fs, 61 dB, 17.1 MHz) with an ultra‐low threshold of 30 mW. The strategy of controllable growth of free‐standing 2D material facilitates a clean interface between the saturable absorber and fibers, which is favorable for high‐performance ultrafast photonic devices. [ABSTRACT FROM AUTHOR]

Delocalized electron and phonon structures are directives for rationally tuning the intrinsic physicochemical properties of 2D materials by redistributing electronic density. However, it is still challenging to accurately manipulate the delocalized electron and systematically study the relationships between physiochemical properties and practical nanodevices. Herein, the effects of delocalized electrons engineering on blue‐arsenic‐phosphorus (β‐AsP)‐based practical devices are systematically investigated via implementing vacancies or heteroatom doping. A tendency of carrier conductivity property from “half‐metal” to “metal” is initially found when tuning the electronic structure of β‐AsP with adjustable vacancy concentrations below 2 at% or above 3 at%, which can be ascribed to the introduction of delocalized electrons that cause asymmetric contributions to the electronic states near the implementation site. In optical logic device simulations, broadband response, triangular wave circuit system signal, and reverse polarization anisotropy are achieved by adjusting the vacancy concentration, while extinction ratios are as high as 1561. The electric and thermic‐logic devices realize the highest available reported giant magnetoresistance (MR) up to 1013% and 1039% at vacancy concentrations of 1.67% and 0.89%, respectively, which is significantly superior to the reports. The results shed light on the electronic delocalization strategy of regulating internal structures to achieve highly efficient nanodevices. [ABSTRACT FROM AUTHOR]

Polymyxin B (PMB) is often considered as the last line of defense for treating carbapenem‐resistant Klebsiella pneumoniae (CRKP). However, its efficacy is hindered by limited penetration across the blood‐air barrier in the lung due to its low lipid solubility. To simultaneously increase PMB in epithelial lining fluid while suppressing the excessive inflammatory response in the lung, a novel nano‐biomimetic system “Siv‐PMB@G4@MM” is designed and fabricated by encapsulating PMB‐ and anti‐inflammatory Sivelestat (Siv)‐loaded G4 PAMAM dendrimers with macrophage membranes (MM). The Siv‐PMB@G4@MM displayed a superior acidic pH‐responsive release property and can target inflamed lung tissues, greatly increasing the concentrations of PMB and Siv at the infection site. Compared with free drugs, Siv‐PMB@G4@MM demonstrated superior synergistic antibacterial and anti‐inflammatory activities. Moreover, due to the ability of MM to sequester lipopolysaccharide (LPS) and some pro‐inflammatory cytokines, Siv‐PMB@G4@MM further enhanced the anti‐inflammatory potential of Siv. In mouse models of LPS‐induced acute lung injury, pulmonary bacterial infection, and sepsis‐induced pneumonia, Siv‐PMB@G4@MM significantly reduced inflammatory responses and/or bacterial burdens, mitigated neutrophil infiltration and pulmonary edema, and decreased neutrophil extracellular trap (NET) secretion. The highly improved biocompatibility and efficiency of the multifunctional Siv‐PMB@G4@MM presents a promising strategy for the clinical treatment of antibiotic‐resistant bacterial pneumonia. [ABSTRACT FROM AUTHOR]