巯基自组装修饰恒电位共价键合法固定基因电化学传感器的制备与表征

以金电极为基体电极,采用巯基乙醇自组装法制备了巯基乙醇自组装膜修饰电极,再以碳二亚胺为交联剂用控制电位共价键合法将DNA固定在巯基乙醇单分子层上形成了基因修饰电极。以亚甲蓝为电化学杂交指示剂,采用循环伏安法、微分脉冲伏安法等电化学方法对基因电化学传感器进行了表征。结果表明,该方法能够将DNA稳定地固定于电极表面,可用于制备自组装修饰基因电化学传感器。     

Reconstruction of the Indium Tin Oxide Surface Enhances the Adsorption of High-Density Self-Assembled Monolayer for Perovskite/Silicon Tandem Solar Cells

Self-assembled monolayers (SAMs) are widely used as carrier transport interlayers for enabling high-efficiency perovskite solar cells (PSCs). However, achieving uniform and pinhole-free monolayers on metal oxide (e.g., indium tin oxide, ITO) surfaces is still challenging due to the sensitivity of SAM adsorption to the complex oxide's surface chemistry. Here, the hydrofluoric acid and the subsequent UV–ozone treatment are employed to reconstruct the ITO surface by selectively removing the undesired terminal hydroxyl and hydrolysis product. This can significantly increase the ITO surface activity and area, thus facilitating the adsorption of high-density SAMs. The resultant fluorinated surface can also prevent the direct contact of ITO with the perovskite active layer and passivate the perovskite bottom interface. Benefiting from the synergistically improved perovskite film formation, charge extraction, energy level alignment, and interfacial chemical stability, the corresponding PSC achieves a greatly enhanced power conversion efficiency of 21.3%, along with an enhanced long-term stability as compared to the control counterpart. Furthermore, a semitransparent PSC with a certified efficiency of 19.0% (with a record fill factor of 84.1%) and a four-terminal perovskite/silicon tandem with an efficiency of 28.4% are also demonstrated.     

Atomically Dispersed Dual-Site Cathode with a Record High Sulfur Mass Loading for High-Performance Room-Temperature Sodium–Sulfur Batteries

Room-temperature sodium–sulfur (RT-Na/S) batteries possess high potential for grid-scale stationary energy storage due to their low cost and high energy density. However, the issues arising from the low S mass loading and poor cycling stability caused by the shuttle effect of polysulfides seriously limit their operating capacity and cycling capability. Herein, sulfur-doped graphene frameworks supporting atomically dispersed 2H-MoS₂ and Mo₁ (S@MoS₂-Mo₁/SGF) with a record high sulfur mass loading of 80.9 wt.% are synthesized as an integrated dual active sites cathode for RT-Na/S batteries. Impressively, the as-prepared S@MoS₂-Mo₁/SGF display unprecedented cyclic stability with a high initial capacity of 1017 mAh g⁻¹ at 0.1 A g⁻¹ and a low-capacity fading rate of 0.05% per cycle over 1000 cycles. Experimental and computational results including X-ray absorption spectroscopy, in situ synchrotron X-ray diffraction and density-functional theory calculations reveal that atomic-level Mo in this integrated dual-active-site forms a delocalized electron system, which could improve the reactivity of sulfur and reaction reversibility of S and Na, greatly alleviating the shuttle effect. The findings not only provide an effective strategy to fabricate high-performance dual-site cathodes, but also deepen the understanding of their enhancement mechanisms at an atomic level.     

Donor:Acceptor Janus Nanoparticle-Based Films as Photoactive Layers: Control of Assembly and Impact on Performance of Devices

Water-processable organic semiconductor nanoparticles (NPs) are considered promising materials for the next-generation of optoelectronic applications due to their controlled size, internal structure, and environmentally friendly processing. Reasonably, the controllable assembly of donor:acceptor (D:A) NPs on large areas, quality, and packing density of deposited films, as well as layer morphology, will influence the effectiveness of charge transfer at an interface and the final performance of designed optoelectronic devices.This work represents an easy and effective approach for designing self-assembled monolayers of D:A NPs. In this self-assembly procedure, the NP arrays are prepared on a large scale (2 × 2 cm²) at the air/water interface with controlled packing density and morphology. Due to the unique structure of individual D:A Janus particles and their assembled arrays, the Janus nanoparticle (JNP)-based device exhibits an 80% improvement of electron mobility and more balanced charge extraction compared to the conventional core–shell NP-based device. An outstanding performance of polymer solar cells with over 5% efficiency is achieved after post-annealing treatment of assembled arrays, representing one of the best results for NP-based organic photovoltaics. Ultimately, this work provides a new protocol for processing water-processable organic semiconductor colloids and future optoelectronic fabrication.     

Piezo-Activated Atomic-Thin Molybdenum Disulfide/MXene Nanoenzyme for Integrated and Efficient Tumor Therapy via Ultrasound-Triggered Schottky Electric Field

Monolayer molybdenum disulfide (MoS₂) nanoenzymes exhibit a piezoelectric polarization, which generates reactive oxygen species to inactivate tumors under ultrasonic strain. However, its therapeutic efficiency is far away from satisfactory, due to stackable MoS₂, quenching of piezo-generated charges, and monotherapy. Herein, chitosan-exfoliated monolayer MoS₂ (Ch-MS) is composited with atomic-thin MXene, Ti₃C₂ (TC), to self-assemble a multimodal nanoplatform, Ti₃C₂-Chitosan-MoS₂ (TC@Ch-MS), for tumor inactivation. TC@Ch-MS not only inherits piezoelectricity from monolayer MoS₂, but also maintains remarkable stability. Intrinsic metallic MXene combines with MoS₂ to construct an interfacial Schottky heterojunction, facilitating the separation of electron–hole pairs and endowing TC@Ch-MS increase-sensitivity magnetic resonance imaging responding. Schottky interface also leads to peroxidase mimetics with excellent catalytic performance toward H₂O₂ in the tumor microenvironment under mechanical vibration. TC@Ch-MS possesses the superior photothermal conversion efficiency than pristine TC under near-infrared ray illumination, attributed to its enhanced interlaminar conductivity. Meanwhile, TC@Ch-MS realizes optimized efficiency on tumor apoptosis with immunotherapy. Therefore, TC@Ch-MS achieves an integrated diagnosis and multimodal treatment nanoplatform, whereas the toxicity to normal tissue cells is negligible. This work may shed fresh light on optimizing the piezoelectric materials in biological applications, and also give prominence to the significance of intrinsic metallicity in MXene.