Advanced Materials Interfaces最新文献

Metal Cluster-Based Chemical Sensor

The development of a nanohybrid based on trinuclear molybdenum sulfido clusters supported onto graphene and its application to detect toxic and harmful gaseous molecules is described. The outstanding sensing performance toward CO₂ makes these materials promising for a new generation of molybdenum resistive interrogators for the control of air quality. More details can be found in article 2400590 by Juan Casanova-Chafer, Eduard Llobet, and Marta Feliz.

Planetary Lithium Islands

The cover image of the article 2400693 by Yi Cui, Stacey F. Bent, and co-workers depicts a unique planetary-like microstructure with lithium islands achieved by resistive hafnia coating on copper. The work introduces an interface engineering approach that allows the decoupling of two critical lithium (Li)-metal battery parameters—Li-morphology and solid electrolyte interphase (SEI)—in their kinetically convoluted regime. The article highlights that Li morphological control is more practical due to the challenges in SEI preservation.

The transport of hydrogen through an anion-exchange membrane (AEM) is analyzed by in-line product gas analysis in a large dynamic range (0.1–2 Acm⁻²) at ambient pressure and correlated to ex situ membrane properties, including volumetric electrolyte uptake, dimensional swelling and diffusivities. A commercial AF3-HWK9-75-X membrane from Ionomr Innovations Inc. is characterized and employed in a 25 cm² electrolyzer cell, which is operated for 56 h at 60 °C in 1 M KOH solution. A model of the membrane is developed, based on a combination of existing theoretical knowledge regarding liquid electrolytes and measured properties of the membrane. The model is employed to quantify the transport parameters through the membrane and the porous electrode. The hydrogen transport through the membrane is 770 times slower than through the electrode. The anion-exchange membrane permits a low degree of gas crossover, with a hydrogen-in-oxygen concentration of $��0.37��\%�$ at 2 Acm⁻². The model indicates that modifying the membrane's microstructure has a more pronounced effect on the gas crossover than altering the swollen thickness. A correlation is derived to estimate the polymer diffusivity from the derived effective diffusivity through the membrane, which allows the determination of preferred membrane properties to lower hydrogen crossover.

Physisorption of antibodies onto surfaces is a low-cost, rapid, and effective approach for immobilizing bioreceptors in applications such as bioelectronic sensors. However, there is a prevailing notion that physisorbed protein layers lack structural order, thus potentially compromising their stability and sensitivity compared to antibody films that are covalently attached to the substrate surface. This study demonstrates the preferential orientation of β-sheets within the secondary structure of protein layers, specifically anti-immunoglobulin G (anti-IgG) and bovine serum albumin (BSA), when physisorbed onto gold (Au) thin films. Using polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS) and infrared attenuated total reflection (IR-ATR) spectroscopy, it has been confirmed that the β-strands in these protein layers are tilted relative to the surface normal by average angles of 75.3° ± 0.4° for anti-IgG and of 79.3 ± 0.2° for BSA. These results are obtained by analyzing the orientation of the transition dipole moments (TDMs) associated with the amide I molecular vibrations derived from a comparison between experimental and simulated mid-infrared spectra assuming isotropically oriented TDMs. The simulations incorporate refractive and absorption index dispersions obtained from the IR-ATR spectra. Thus obtained findings offer valuable molecular-level insights facilitating the design and optimization of biofunctionalized interfaces in advanced biomedical and biosensing applications.

The advancement of effective techniques for the production of activated carbon has been a prominent focus of research. Herein, this work designs and successfully prepares a nontoxic, environmentally friendly organic activator on the surface of carbon materials through in situ organic fermentation treatment method. The production of activated carbon via this novel organic activator is at a temperature of 850 °C under CO₂ atmosphere for an activation time of 90 min, showing a specific surface area (S_BET) of 1354 m² g⁻¹, an adsorption capacity of iodine (Q_I) of 1195 mg g⁻¹_, and a total pore volume (V_tot) of 0.855 cm³ g⁻¹. Compared to the activated carbon prepared at high temperature under pure CO₂, these results represent increases of 69.67%, 53.01%, and 93.44% in S_BET, Q_I, and V_tot values, respectively. By means of thermogravimetric (TG) analysis and simultaneous thermal analysis-Fourier transform infrared spectroscopy-gas chromatography/mass spectrometry a suggested activation process and mechanism of the novel organic activators is proposed. This organic activator is not only used for semi-coke (SC) based activated carbon preparation and saturated activated carbon (SAC) regeneration, but also attracts other industrial activated carbon production.

Single-walled carbon nanotube (SWCNT)-based optical biosensors are shown to detect hydrolase activity directly on target substrates. This study presents a metastable protein conjugation approach to immobilize hydrophobic proteins and enhance  sensitivity of protease detection. The method combines covalent conjugation of substrate proteins via carbodiimide chemistry with non-covalent polymer wrapping of SWCNT, carboxymethyl cellulose (CMC). The formation of protein-SWCNT complexes as a result of multi-site conjugation between the proteins and carboxyl groups, enabled iterative pelleting, washing, and resuspension steps to be applied to the probes which allowed for the removal of unbound proteins and residual materials, enhancing the sensor's sensitivity by approximately threefold, reaching a limit of detection (LOD) of 6.4 ng ml⁻¹ in a 5 minute reaction. This immobilization approach is applied to extracellular matrix (ECM) proteins such as gelatin and collagen to detect ECM degrading enzyme activity. ECM degrading enzymes caused a fluorescent intensity decrease of the SWCNT probes, enabling quantification of enzyme concentration between the range 160 ng ml⁻¹ to 100 µg ml⁻¹ within 5 minutes of reaction. This hybrid approach provides a rapid and sensitive platform for detecting extracellular degrading enzymes with potential applications in cancer diagnosis and prognosis, wound healing, high-throughput screening for enzyme inhibitors, and drug discovery.

Surface-enhanced Raman spectroscopy (SERS) technology boasts merits of fingerprint recognition, a low detection limit, high sensitivity, and straightforward operation, and holds a significant position in the realm of molecular detection (even at the single-molecule level). Recently, molybdenum disulfide (MoS₂), as a special SERS substrate, has demonstrated various advantages like high molecular compatibility and an anti-fluorescence background, thus emerging as a promising non-metal substrate. Nevertheless, so far, how to improve and achieve SERS effects comparable to metal substrates remains a challenge for MoS₂ based substrates. Therefore, this work presents and acquires a 3D hollow structured MoS₂, which can be achieved through a simple hydrothermal method. Fortunately, the substrate achieves a detection limit of 10⁻⁸ M and an enhancement factor of 10⁶ for rhodamine 6G (R6G) molecules, significantly improving the performance of the non-noble-metal MoS₂ SERS. Theoretical analysis suggests that this should be attributed to the enhanced charge transfer between the substrate and probe molecules brought by the distinct monolayer self-assembly and oxygen substitution in the 3D MoS₂ architecture. The work provides a novel method to enhance the SERS performance of 2D materials, which is readily achievable and is expected to become a key cornerstone for the development of composite substrates.

Oxygen in the excited state is essential for organic synthesis and medical treatment. Herein, a novel phenomenon is reported in which the magnetic ground state of molecular oxygen undergoes a transition at room temperature from S = 1 to S = 1/2, corresponding to the transition of O₂ from a triplet to a doublet state after stable physical adsorption on the defect-free surface of bulk VSe₂. This density functional theory (DFT) calculations demonstrate the stable physical adsorption of O₂ on both 1T- and 2H-VSe₂ surfaces without further decomposition. Electron spin resonance (ESR) measurements confirm the spin state transition. Theoretical simulations reveal the charge transfer from entangled V-3d and Se-4p bands to oxygen as the leading cause of the spin state transition. This mechanism has not been previously proposed and offers multiple potential applications, from organic synthesis to medicine. Moreover, this approach can be extended to reveal new aspects of known catalytic materials and to design novel catalysts.

Encapsulation creates a protective outer layer(s) around a core cargo, which safeguards the cargo in aggressive surroundings. It also serves as a platform to impart various desired characteristics to the core cargo, including shell-functionalization and targeted release characteristics. Encapsulation can be broadly classified into three categories: physical, chemical, and physicochemical techniques. This perspective focuses on an emerging class of impact-driven physical encapsulation techniques, which offers several lucrative prospects compared to conventional encapsulation methods, including straightforward execution and ultrafast yet controlled wrapping. Two different categories of impact-driven methods for achieving stable, ultrafast encapsulation of various core liquid analytes with one or more wrapping layers are discussed, namely, elastocapillary wrapping with ultrathin sheet(s) and a liquid–liquid encapsulation framework, where thin liquid film(s) are used to wrap liquid analytes, with an emphasis on the latter. The promising prospects of both approaches are discussed, recent developments are outlined, and areas of future research that can lead to a truly versatile and comprehensive encapsulation platform applicable to a broad range of practical applications are highlighted.