The introduction of stimulus‐responsive groups can give polymers some material properties that cannot be realized simply by design and synthesis. Polyolefins, due to their nonpolar nature, suffer from poor compatibility with polar materials; however, directly grafting polar groups like hydroxyls onto their surface via traditional synthesis risks compromising their intrinsic hydrophobicity and is further hindered by challenges such as poisoning effects on catalysts from polar moieties. In this work, a photoresponsive strategy for polyolefins that enables surface introduction of hydroxyl groups without altering the bulk properties has been introduced. By copolymerizing ethylene with acrylate‐based comonomers, we synthesized functional polyolefins capable of undergoing photo‐Fries rearrangement under both UV and natural sunlight irradiation. This process selectively generates reactive phenolic hydroxyl groups at the material surface. The phototreated polymers exhibit significantly improved surface properties, including enhanced hydrophilicity, dyeability, and interfacial adhesion to metals. Additionally, we demonstrate a scalable route to these photoresponsive polyolefins via post‐functionalization of commercial maleic anhydride‐grafted polyolefins, establishing a versatile platform for further customization. This work highlights how light responsiveness can overcome the constraints of traditional synthesis to achieve cross‐scale structural control in polymers.

In point-of-care testing (POCT) scenarios, electrochemical nucleic acid (ECNA) biosensors usually face limitations in interfacial kinetics and sensitivity. Herein, we present a dual recognition sequences-containing capture probe (DRCP)-based ECNA biosensor in combination with a reverse-transcription asymmetric recombinase polymerase amplification (RT-aRPA) sample pretreatment for fast and ultrasensitive viral RNA detection. The DRCP was self-assembled on electrode surfaces and was designed to consist of two identical ssDNA segments linked by an amide bond, each featuring a recognition sequence with a toehold. The presence of dual toehold domains facilitated the acceleration of target-specific strand displacement by 2.5-fold compared to single recognition sequences-containing capture probe systems, enabling pM-level RNA quantification within 10 min. Contrasting with conventional signal enhancement modes that suffer from sluggish interfacial assembly, the disassembly-induced signal attenuation mechanism effectively minimized the interfacial steric hindrance. Coupled with RT-aRPA, the system achieved 200 copies mL(-1) sensitivity, completing the entire "processed sample-to-result" workflow in 20 min, outperforming PCR-based methods (>2 h) while eliminating bulky instrumentation, and therefore meeting POCT requirements. Furthermore, a field-deployable POCT prototype was validated with the lysed clinical throat swab samples from SARS-CoV-2 patients. This study This study might be useful for the development of advanced ECNA sensors for POCT applications, e.g., electrochemically decentralized POCT diagnosis of early virus infection.

Single-molecule spins are regarded as promising candidates for the miniaturization of magnetic storage devices at the nanoscale. The engineering of these spins can be facilitated by the Kondo effect observed in surface molecular systems, which necessitates a comprehensive understanding of the interactions between molecules and environments. In this study, we provide definitive evidence that the Kondo signature detected in a manganese phthalocyanine (MnPc) molecule adsorbed on an Au(111) surface, as indicated by previous scanning tunneling microscopy experiments, can be entirely suppressed through a chemical stimulus. This suppression is achieved by the coordination of nitric oxide (NO) and carbon monoxide (CO) as axial ligands to the molecule. Utilizing density functional theory calculations, we demonstrate that such selective coordination of CO and NO induces a considerable distortion in its molecular conformation, resulting in an increased distance between the Mn center and the substrate. This alteration diminishes the coupling with the substrate and modifies the local electronic configuration of the Mn center compared to the uncoordinated state, which accounts for the attenuation of the Kondo signature in the MnPc/Au(111) system. Specifically, when NO coordinates with the Mn center in a linear configuration, the significant hybridization between the 2π* orbital of the NO molecule and the dπ orbitals of the Mn center transforms the molecular spin state from S = 3/2 to S = 0, leading to the complete disappearance of the Kondo effect. In contrast, although the unpaired spin in the dxy orbital of the Mn center persists following CO coordination, its hybridization with the substrate near the Fermi level is insufficient due to the shape and orientation of the orbital, effectively closing the Kondo screening channel. As a result, the Kondo signature that would typically be expected from the MnPc/Au(111) system is absent after CO coordination. Our findings highlight the pivotal role of orbital symmetry in the Kondo effect, which can significantly affect hybridization with the substrate and, consequently, the Kondo screening process. The insights gained from this research provide a valuable framework for manipulating many-body quantum states in similar magnetic single-molecule adsorption systems.

Interfacial structure and characteristics of heterogeneous interfaces are essential for the macro-properties of composites. Particularly for graphene/metal heterojunctions, interface rotation angle variations may cause distinctions in interfacial electronic properties. However, direct experimental evidence is lacking in understanding the corresponding mechanisms. Here, we investigated influential mechanisms of rotation angle differences on interfacial electronic coupling in classical graphene/copper (Gr/Cu) immiscible epitaxial systems. Atomic force microscopy combined with surface potential measurement confirmed that the different rotation angles (similar to 8 degrees) contributed to a modulated Fermi level in Gr/Cu, indicating varied electron transfer at the interface. Through theoretical analysis, it is found that the modulated interfacial electronic behavior is primarily ascribed to different overlap between C-p and Cu-3d orbitals, resulting from varying fluctuation of graphene and changed minimum Gr/Cu distance at different rotation angles. The mechanism of interfacial electronic properties modulated by the rotation angles could further guide the design of heterogeneous interfaces in electronic applications.

Pathogenic bacterial infections pose major health threats and economic burdens. Rapid and highly sensitive biochemical sensors are essential for bacterial detection in food safety and clinical applications. Here, we introduce a graphene oxide (GO)-based magnetic nanomechanical array sensor that utilizes the large surface area of GO to bind more magnetic nanoparticles (MNPs) and aptamers. Rapid and ultra-sensitive detection can be achieved even at extremely low target concentrations. This approach can directly detect a single Escherichia coli cell without time-consuming bacterial culture, and the linear detection range is 1–100 CFU·mL−1. Meanwhile, the sensor showed good specificity, reproducibility, stability, and stance to interference, and could detect 1 CFU·mL−1 Escherichia coli in milk. Moreover, we realized the simultaneous detection of two bacteria at extremely low concentrations, which proved that the sensor had the potential for high-throughput detection. In addition, for extremely low-concentration samples (< 100 CFU·mL−1), we controlled the magnetic force at the tip of the microcantilever, greatly enhancing its deflection and sensitivity. This method provides a novel and ultrasensitive method for the timely detection of pathogenic bacteria, and can also be applied to the highly sensitive detection of other targets such as DNA, small molecules, proteins, and viruses by using different probes. Our research provides a promising tool for effective, rapid and highly sensitive detection in the field of public health and food safety.

Schottky-type self-powered UV photodetectors are promising for next-generation imaging systems. Nevertheless, conventional device fabrication using high-energy metal deposition brings unintentional interface defects, leading to deteriorated device performance and inhomogeneities. Emerging...

Magnetic molecules on ferromagnetic metallic substrates have been widely explored to exploit the potential for molecular magnetic storage and spintronics applications. Recent advances in these hybrid interfaces integrated with two-dimensional materials have been proposed as a flexible platform for realizing new spin-related effects. Herein, the impact of inserting graphene on the electronic and magnetic properties of a family of transition metal phthalocyanines (TMPcs, TM = Cr, Mn, Fe, Co, and Cu) deposited on ferromagnetic Ni(111) surfaces have been systematically rationalized by density functional theory analysis. Our calculations reveal that the magnetic exchange interaction across the molecule-substrate interfaces can be significantly mediated by the introduction of a graphene interlayer. Interestingly, these TMPcs exhibit ferromagnetic coupling with the Ni substrate. However, the strength of this coupling is reduced in the presence of a graphene decoupling layer, with the exception of CoPc. In the case of CoPc, the original ferromagnetic coupling with Ni(111) can be altered to antiferromagnetic when a graphene interlayer is introduced. By analyzing the different channels of communication involved in the spin interaction between the molecule and the magnetic substrate, we attribute these significant differences to the varied influences on the exchange interaction caused by the intermediary graphene layer. The presence of the inserted graphene layer may block the direct exchange interaction between the TMPc molecule and substrate, while the indirect superexchange interaction facilitated by the nitrogen atoms of the organic ligands is only reduced. Our study thus demonstrates that the inserted graphene can serve as an optimal intermediary layer for mediating the magnetic couplings across the molecule-substrate interfaces while allowing effective spin communication between them. These findings provide important insights into relevant experiments and offer a promising strategy to control the magnetic exchange interactions via utilizing graphene at metal-molecule interfaces.

As a recent successfully exfoliated non-van der Waals layered material, AgCrS2 has received a lot of attention. Motivated by its structure-related magnetic and ferroelectric behavior, a theoretical study on its exfoliated monolayer AgCr2S4 has been carried out in the present work. Based on density functional theory, the ground state and magnetic order of monolayer AgCr2S4 have been determined. The centrosymmetry emerges upon two-dimensional confinement and thus eliminates the bulk polarity. Moreover, two-dimensional ferromagnetism appears in the CrS2 layer of AgCr2S4 and can persist up to room temperature. The surface adsorption has also been taken into consideration, which shows a nonmonotonic effect on the ionic conductivity through ion displacement of the interlayer Ag, but has little impact on the layered magnetic structure.

Exosomes are a class of nanoscale vesicles secreted by cells, which contain abundant information closely related to parental cells. The ultrasensitive detection of cancer-derived exosomes is highly significant for early non-invasive diagnosis of cancer. Here, an ultrasensitive nanomechanical sensor is reported, which uses a magnetic-driven microcantilever array to selectively detect oncogenic exosomes. A magnetic force, which can produce a far greater deflection of microcantilever than that produced by the intermolecular interaction force even with very low concentrations of target substances, is introduced. This method reduced the detection limit to less than 10 exosomes mL(-1). Direct detection of exosomes in the serum of patients with breast cancer and in healthy people showed a significant difference. This work improved the sensitivity by five orders of magnitude as compared to that of traditional nanomechanical sensing based on surface stress mode. This method can be applied parallelly for highly sensitive detection of other microorganisms (such as bacteria and viruses) by using different probe molecules, which can provide a supersensitive detection approach for cancer diagnosis, food safety, and SARS-CoV-2 infection.

The intrinsically fragile nature and leakage of the enzymes is a major obstacle for the commercial sensor of a continuous glucose monitoring system. Herein, a dual confinement effect is developed in a three dimensional (3D) nanocage-based zeolite imidazole framework (NC-ZIF), during which the high-loading enzymes can be well encapsulated with unusual bioactivity and stability. The shell of NC-ZIF sets the first confinement to prevent enzymes leakage, and the interior nanocage of NC-ZIF provides second confinement to immobilize enzymes and offers a spacious environment to maintain their conformational freedom. Moreover, the mesoporosity of the formed NC-ZIF can be precisely controlled, which can effectively enhance the mass transport. The resulted GOx/ Hemin@NC-ZIF multi-enzymes system could not only realize rapid detection of glucose by colorimetric and electrochemical sensors with high catalytic cascade activity (with an 8.3-fold and 16-fold enhancements in comparison with free enzymes in solution, respectively), but also exhibit long-term stability, excellent selectivity and reusability. More importantly, the based wearable sweatband sensor measurement results showed a high correlation ( 0.84, P < 0.001) with the levels measured by commercial glucometer. The reported dual confinement strategy opens up a window to immobilize enzymes with enhanced catalytic efficiency and stability for clinical-grade noninvasive continuous glucose sensor.

Recent scanning tunneling spectroscopy with single metallocene molecule-functionalized tips have proved to be a powerful tool to probe and control individual spins and spin-spin exchange interactions due to the robustness of the magnetic properties of the metallocene molecule in different surroundings. However, accurate prediction of such robustness at a first-principles-based level by the conventional density functional theory (DFT) has remained challenging. In this paper, we have performed a detailed investigation of the evolution of electronic and magnetic properties of a nickelocene molecule (NiCp2) in different environments, i.e., free-standing, adsorbed on Cu(100) and as a functionalized tip apex. Using an embedding method, which combines DFT and the complete active space self-consistent field (CASSCF) method recently developed, we demonstrate that the nickelocene molecule almost preserves its spin and magnetic anisotropy upon adsorption on Cu(100), and also in the position of the tip apex. In particular, the cyclic π* orbital of the Cp rings could hybridize with the singly occupied dπ orbitals of the Ni center of the molecule, protecting these orbitals from external states. Hence the molecular spin maintains S = 1, the same as in the free-standing case, and its magnetic anisotropy is also robust with energies of 3.56, 3.34, and 3.51 meV in free-standing, adsorbed on Cu(100), and functionalized tip apex states, respectively, in good agreement with previous theoretical and experimental results. This work thus provides a first-principles-based understanding of the relevant experiments. Such agreement between theoretical simulations and experimental measurements highlights the potential usefulness of the method for investigating the local electronic and spin states of organometallic molecule-surface composite systems.

Ultrasensitive molecular detection and quantization are crucial for many applications including clinical diagnostics, functional proteomics, and drug discovery; however, conventional biochemical sensors cannot satisfy the stringent requirements, and this has resulted in a long-standing dilemma regarding sensitivity improvement. To this end, we have developed an ultrasensitive relay-type nanomechanical sensor based on a magneto lever. By establishing the link between very weak molecular interaction and five orders of magnitude larger magnetic force, analytes at ultratrace level can produce a clearly observable mechanical response. Initially, proof-of-concept studies showed an improved detection limit up to five orders of magnitude when employing the magneto lever, as compared with direct detection using probe alone. In this study, we subsequently demonstrated that the relay-type sensing mode was universal in application ranging from micromolecule to macromolecule detection, which can be easily extended to detect enzymes, DNA, proteins, cells, viruses, bacteria, chemicals, etc. Importantly, we found that, sensitivity was no longer subject to probe affinity when the magneto lever was sufficiently high, theoretically, even reaching single -molecule resolution.

A novel polyzwitterionic eutectogel made with a DES (ChCl–EG–urea), zwitterionic sulfobetaine, and Zn(ClO 4 ) 2 with high ion conductivity has been used as an electrolyte for quasi-solid state zinc ion batteries with efficient suppression of dendrite growth.

The beginning of a mammalian life commences with a fertilized oocyte. The study of oocytes is certainly one of the most intriguing scientific questions of our time. Herein, we studied oocytes from a mechanical perspective and characterized the typical life activities of oocytes by nanomechanical vibrations. During the development of oocytes from the germinal vesicle (GV) stage to the zygotes, the GV stage oocytes induced a significant nanomechanical vibration, compared with the oocytes in meiosis I (MI) and meiosis II (MII) stages and zygotes. We analyzed the characteristics of mechanical vibrations of oocytes, including the amplitude as well as the frequency. It showed that the amplitude and frequency of nanomechanical vibrations induced by oocytes were caused by the cytoskeleton (microfilaments) and the distribution of metabolic characteristics (mitochondria) within oocytes. This work provides a new perspective for clinical quality assessment and basic research of oocytes, and can open new doors for development of life science.

A high-strength PVA-based eutectogel has been synthesized by a strategy of solvent-induced microphase separation. Here, PVA was dissolved in water, and green solvent DES (choline chloride/glycerol) was introduced to induce PVA to undergo microphase separation, leading to poorly solvated domains and highly solvated domains. In poorly solvated domains, the PVA chains were folded and crystallized, and the formed crystalline domains served as physical cross-linkers. Such cross-linking structures endowed the eutectogels with remarkable mechanical properties, showing strength in tension reaching up to 1.2 MPa and elongation at a break of 405%, with rupture toughness of 3.23 MJ m-3. Meanwhile, the as-obtained eutectogel possessed reprocessability and could be recycled through high-temperature dissolution and recasting. In addition, the eutectogel also exhibited excellent frost resistance, and its ionic conductivity could still reach 0.62 mS cm-1 at -40 °C. In addition, the eutectogel can maintain a stable output signal during a multiple strain cycle, showing the potential application in the flexible sensor. The eutectogel is capable of detecting the bending movement of joints and identifying the different bending angles of fingers, showing a certain applied potential in motion detection of the human body.

Since the first report on truly two-dimensional (2D) magnetic materials in 2017, a wide variety of merging 2D magnetic materials with unusual physical characteristics have been discovered and thus provide an effective platform for exploring the associated novel 2D spintronic devices, which have been made significant progress in both theoretical and experimental studies. Herein, we make a comprehensive review on the recent scientific endeavors and advances on the various engineering strategies on 2D ferromagnets, such as strain-, doping-, structural- and electric field-engineering, toward practical spintronic applications, including spin tunneling junctions, spin field-effect transistors and spin logic gate, etc. In the last, we discuss on current challenges and future opportunities in this field, which may provide useful guidelines for scientists who are exploring the fundamental physical properties and practical spintronic devices of low-dimensional magnets.

Early cancer diagnosis requires ultrasensitive detection of tumor markers in blood. To this end, we develop a novel microcantilever immunosensor using nanobodies (Nbs) as receptors. As the smallest antibody (Ab) entity comprising an intact antigen-binding site, Nbs achieve dense receptor layers and short distances between antigen-binding regions and sensor surfaces, which significantly elevate the generation and transmission of surface stress. Owing to the inherent thiol group at the C-terminus, Nbs are covalently immobilized on microcantilever surfaces in directed orientation via one-step reaction, which further enhances the stress generation. For microcantilever-based nanomechanical sensor, these advantages dramatically increase the sensor sensitivity. Thus, Nb-functionalized microcantilevers can detect picomolar concentrations of tumor markers with three orders of magnitude higher sensitivity, when compared with conventional Ab-functionalized microcantilevers. This proof-of-concept study demonstrates an ultrasensitive, label-free, rapid, and low-cost method for tumor marker detection. Moreover, interestingly, we find Nb inactivation on sensor interfaces when using macromolecule blocking reagents. The adsorption-induced inactivation is presumably caused by the change of interfacial properties, due to binding site occlusion upon complex coimmobilization formations. Our findings are generalized to any coimmobilization methodology for Nbs and, thus, for the construction of high-performance immuno-surfaces.

A pair of ruthenium(II) complex enantiomers, Δ- and Λ-[Ru(bpy)2MBIP]2+ (bpy = 2,2'-bipyridine, MBIP = 2-(3-bromophenyl)imidazo[5,6-f]phenanthroline), were designed, synthesized, and characterized. Comparative studies between the enantiomers on their binding behaviors to calf thymus DNA (CT-DNA) were conducted using UV-visible, fluorescence, and circular dichroism spectroscopies, viscosity measurements, isothermal titration calorimetry, a photocleavage experiment, and molecular simulation. The experimental results indicated that both the enantiomers spontaneously bound to CT-DNA through intercalation stabilized by the van der Waals force or the hydrogen bond and driven by enthalpy and that Δ-[Ru(bpy)2MBIP]2+ intercalated into DNA more deeply than Λ-[Ru(bpy)2MBIP]2+ did and exhibited a better DNA photocleavage ability. Molecular simulation further indicated that Δ-[Ru(bpy)2MBIP]2+ more preferentially intercalated between the base pairs of CT-DNA to the major groove, and Λ-[Ru(bpy)2MBIP]2+ more favorably intercalated to the minor groove. These research findings should be very helpful to the understanding of the stereoselectivity mechanism of DNA-bindings of metal complexes, and be useful for the design of novel metal-complex-based antitumor drugs with higher efficacy and lower toxicity.

Atomic-scale control of multiple spins with individual addressability enables the bottom-up design of functional quantum devices. Tailored nanostructures can be built with atomic precision using scanning tunneling microscopes, but quantum-coherent driving has thus far been limited to a spin in the tunnel junction. Here we show the ability to drive and detect the spin resonance of a remote spin using the electric field from the tip and a single-atom magnet placed nearby. Read-out was achieved via a weakly coupled second spin in the tunnel junction that acted as a quantum sensor. We simultaneously and independently drove the sensor and remote spins by two radio frequency voltages in double resonance experiments, which provides a path to quantum-coherent multi-spin manipulation in customized spin structures on surfaces. One-Sentence Summary : Using a scanning tunneling microscope, we simultaneously control two spins using one tip, paving the way for multi-spin-qubit operations on surfaces.