SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4360-7
Polarization-sensitive photodetection is critical for advanced optical communication and imaging systems, yet conventional photodetectors suffer from low on-off ratios and limited polarization discrimination. Here, we report gate-tunable PdSe2/WSe2 van der Waals heterostructures that achieve ultrahigh light on-off ratio and polarization-sensitive photodetection. The heterostructure forms a type-II band alignment, enabling efficient charge separation and self-powered operation. By applying a gate voltage, the photoresponse can be modulated, achieving an on-off ratio exceeding 10^6 under illumination. The device exhibits a high responsivity of 1.2 A/W and a specific detectivity of 10^12 Jones at room temperature. Polarization-sensitive measurements reveal a linear dichroism ratio of 2.1 at 532 nm, attributed to the anisotropic crystal structure of PdSe2. The photodetector operates over a broad spectral range from visible to near-infrared (400-1000 nm) with fast response times (rise/fall < 100 μs). The gate-tunable capability allows dynamic control of the photocurrent, enabling adaptive sensing applications. These results demonstrate that PdSe2/WSe2 heterostructures are promising candidates for high-performance, polarization-sensitive photodetectors, offering a pathway for next-generation optoelectronic devices.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3649-0
Injectable hydrogels formed via dynamic chemical crosslinks hold great promise as drug delivery platforms due to their robust yet adaptable nature, stimuli-responsiveness, and tunable structures and properties. However, their inherently high water content poses a significant challenge for the efficient encapsulation and sustained release of hydrophobic drugs. Here, we present a novel injectable hydrogel system constructed via a strain-promoted disulfide-thiol exchange between dithiolane-functionalized polymer strands and thiolated core-shell nanoparticles (NPs) under physiological conditions. The hydrophobic core and hydrophilic shell structure of the NPs enables effective loading and protection of hydrophobic drugs, while rapid gelation occurs upon mixing the thiolated NPs with dithiolane-polymers in phosphate-buffered saline. The hydrogel shows excellent injectability, self-healing capability, in vitro biodegradability, and cytocompatibility. This hydrogel system enables sustained release of hydrophobic drugs over 32 days in aqueous media and supports sequential dual-drug release. Its redox-responsiveness under tumor-mimicking reducing conditions, enabled by the disulfide crosslinks, further facilitates controlled intracellular drug release. This multi-component platform offers a versatile strategy for designing advanced injectable hydrogels with potential applications in hydrophobic drug delivery and other biomedical fields.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4144-y
Developing efficient strategies for electrically manipulating two-dimensional magnetism at room temperature is a key challenge in contemporary spintronics. In this study, we demonstrate giant electromechanical control over the magnetism of the room-temperature van der Waals ferromagnet Fe3GaTe2 by integrating it with the ferroelectric α-In2Se3. Modest gate voltages lead to an almost complete suppression of the coercive field by 96.5%, corresponding to a remarkable peak modulation sensitivity of ~8.1 mT V−1, which stands out among existing van der Waals magnetoelectric systems. Importantly, this substantial magnetoelectric response is predominantly unaffected by voltage polarity, as both positive and negative gate voltages induce similar magnetic modulation effects. To elucidate the underlying mechanism, we tracked the voltage-induced Raman spectral changes, revealing a peak shift of 1.7 cm−1 that accurately represents an effective in-plane tensile strain of ~1.42% under an equivalent bias, demonstrating polarity independence as well. The synchronized magnetic response and strain variation unequivocally indicate that the induced tensile strain serves as the fundamental physical driver behind the magnetic modulation. Additionally, density functional theory calculations corroborate that the reduction in magnetic anisotropy induced by tensile strain results in a decrease in the coercive field. Our work establishes a novel and efficient approach for achieving voltage control of magnetism at room temperature in van der Waals multiferroic heterostructures, highlighting their significant potential for applications in ultra-low-power magnetic logic and sensing technologies.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4117-y
Real-time, in situ imaging of hydrogen peroxide (H2O2), a key reactive oxygen species implicated in various diseases, remains challenging due to limitations of existing probes, such as short emission wavelengths and reliance on external excitation. To address these issues, we developed an H2O2-triggered near-infrared (NIR) chemiluminescence (CL) nanoprobe with aggregation-induced emission (AIE) characteristics for in vivo inflammation imaging and tumor theranostics. This nanoprobe, denoted as CPPO@TN NPs, was constructed by co-encapsulating a tailored AIE photosensitizer (TN) with strong NIR emission and high singlet oxygen (1O2) generation, a H2O2-responsive chemiluminescent substrate (CPPO), and soybean oil (as a retarder) within F-127 micelles. Upon encountering H2O2, the nanoprobe undergoes a persistent chemically initiated electron exchange luminescence (CIEEL) process that activates AIEgens, resulting in intense NIR chemiluminescence and sustained 1O2 production without the need for external irradiation. Leveraging this mechanism, CPPO@TN NPs achieved highly sensitive and specific imaging of drug-induced liver injury and peritonitis in murine models, with exceptional tissue penetration and signal-to-noise ratio. Furthermore, the nanoprobe facilitated effective self-luminescent imaging and photodynamic therapy of tumors, significantly inhibiting tumor growth in a 4T1 tumor-bearing mouse model. This platform provides an external light excitation-free theranostic strategy for H2O2-associated diseases.