ACS Nanoscience Au最新文献

Recently, the advent of health risks due to the cytotoxicity of fine particulate matter (FPM) is concerning. Numerous studies have reported abundant data elucidating the FPM-induced cell death pathways. However, several challenges and knowledge gaps are still confronted nowadays. On one hand, the undefined components of FPM (such as heavy metals, polycyclic aromatic hydrocarbons, and pathogens) are all responsible for detrimental effects, thus rendering it difficult to delineate the specific roles of these copollutants. On the other hand, owing to the crosstalk and interplay among different cell death signaling pathways, precisely determining the threats and risks posed by FPM is difficult. Herein, we recapitulate the current knowledge gaps present in the recent studies regarding FPM-induced cell death, and propose future research directions for policy-making to prevent FPM-induced diseases and improve knowledge concerning the adverse outcome pathways and public health risks of FPM.

Solid-state nanopores have been widely employed in the detection of biomolecules, but low signal-to-noise ratios still represent a major obstacle in the discrimination of nucleic acid and protein sequences substantially smaller than the nanopore diameter. The addition of 50% poly(ethylene) glycol (PEG) to the external solution is a simple way to enhance the detection of such biomolecules. Here, we demonstrate with finite-element modeling and experiments that the addition of PEG to the external solution introduces a strong imbalance in the transport properties of cations and anions, drastically affecting the current response of the nanopore. We further show that the strong asymmetric current response is due to a polarity-dependent ion distribution and transport at the nanopipette tip region, leading to either ion depletion or enrichment for few tens of nanometers across its aperture. We provide evidence that a combination of the decreased/increased diffusion coefficients of cations/anions in the bath outside the nanopore and the interaction between a translocating molecule and the nanopore–bath interface is responsible for the increase in the translocation signals. We expect this new mechanism to contribute to further developments in nanopore sensing by suggesting that tuning the diffusion coefficients of ions could enhance the sensitivity of the system.

Over the past 25 years, metal–organic frameworks (MOFs) have developed into an increasingly intricate class of crystalline porous materials in which the choice of building blocks offers significant control over the physical properties of the resulting material. Despite this complexity, fundamental coordination chemistry design principles provided a strategic basis to design highly stable MOF structures. In this Perspective, we provide an overview of these design strategies and discuss how researchers leverage fundamental chemistry concepts to tune reaction parameters and synthesize highly crystalline MOFs. We then discuss these design principles in the context of several literature examples, highlighting both relevant fundamental chemistry principles and additional design principles required to access stable MOF structures. Finally, we envision how these fundamental concepts may offer access to even more advanced structures with tailored properties as the MOF field looks toward the future.

A liquid-based surface-enhanced Raman spectroscopy assay termed PSALM is developed for the selective sensing of neurotransmitters (NTs) with a limit of detection below the physiological range of NT concentrations in urine. This assay is formed by quick and simple nanoparticle (NP) “mix-and-measure” protocols, in which Fe^III bridges NTs and gold NPs inside the sensing hotspots. Detection limits of NTs from PreNP PSALM are significantly lower than those of PostNP PSALM, when urine is pretreated by affinity separation. Optimized PSALM enables the long-term monitoring of NT variation in urine in conventional settings for the first time, allowing the development of NTs as predictive or correlative biomarkers for clinical diagnosis.

The applications of nanomotors in the biomedical field have been attracting extensive attention. However, it remains a challenge to fabricate nanomotors in a facile way and effectively load drugs for active targeted therapy. In this work, we combine the microwave heating method and chemical vapor deposition (CVD) to fabricate magnetic helical nanomotors efficiently. The microwave heating method can accelerate intermolecular movement, which converts kinetic energy into heat energy and shortens the preparation time of the catalyst used for carbon nanocoil (CNC) synthesis by 15 times. Fe₃O₄ nanoparticles are in situ nucleated on the CNC surface by the microwave heating method to fabricate magnetically driven CNC/Fe₃O₄ nanomotors. In addition, we achieved precise control of the magnetically driven CNC/Fe₃O₄ nanomotors through remote manipulation of magnetic fields. Anticancer drug doxorubicin (DOX) is then efficiently loaded onto the nanomotors via π–π stacking interactions. Finally, the drug-loaded CNC/Fe₃O₄@DOX nanomotor can accurately accomplish cell targeting under external magnetic field control. Under short-time irradiation of near-infrared light, DOX can be quickly released onto target cells to effectively kill the cells. More importantly, CNC/Fe₃O₄@DOX nanomotors allow for single-cell or cell-cluster-targeted anticancer drug delivery, providing a dexterous platform to potentially perform many medically relevant tasks in vivo. The efficient preparation method and application in drug delivery are beneficial for future industrial production and provide inspiration for advanced micro/nanorobotic systems using the CNC as a carrier for a wide range of biomedical applications.

Intermetallic structures whose regular atomic arrays of constituent elements present unique catalytic properties have attracted considerable attention as efficient electrocatalysts for energy conversion reactions. Further performance enhancement in intermetallic catalysts hinges on constructing catalytic surfaces possessing high activity, durability, and selectivity. In this Perspective, we introduce recent endeavors to boost the performance of intermetallic catalysts by generating nanoarchitectures, which have well-defined size, shape, and dimension. We discuss the beneficial effects of nanoarchitectures compared with simple nanoparticles in catalysis. We highlight that the nanoarchitectures have high intrinsic activity owing to their inherent structural factors, including controlled facets, surface defects, strained surfaces, nanoscale confinement effects, and a high density of active sites. We next present notable examples of intermetallic nanoarchitectures, namely, facet-controlled intermetallic nanocrystals and multidimensional nanomaterials. Finally, we suggest the future research directions of intermetallic nanoarchitectures.

A prominent neurotransmitter (NT), dopamine (DA), is a chemical messenger that transmits signals between one neuron to the next to pass on a signal to and from the central nervous system (CNS). The imbalanced concentration of DA may cause numerous neurological sicknesses and syndromes, for example, Parkinson’s disease (PD) and schizophrenia. There are many types of NTs in the brain, including epinephrine, norepinephrine (NE), serotonin, and glutamate. Electrochemical sensors have offered a creative direction to biomedical analysis and testing. Researches are in progress to improve the performance of sensors and develop new protocols for sensor design. This review article focuses on the area of sensor growth to discover the applicability of polymers and metallic particles and composite materials as tools in electrochemical sensor surface incorporation. Electrochemical sensors have attracted the attention of researchers as they possess high sensitivity, quick reaction rate, good controllability, and instantaneous detection. Efficient complex materials provide considerable benefits for biological detection as they have exclusive chemical and physical properties. Due to distinctive electrocatalytic characteristics, metallic nanoparticles add fascinating traits to materials that depend on the material’s morphology and size. Herein, we have collected much information on NTs and their importance within the physiological system. Furthermore, the electrochemical sensors and corresponding techniques (such as voltammetric, amperometry, impedance, and chronoamperometry) and the different types of electrodes’ roles in the analysis of NTs are discussed. Furthermore, other methods for detecting NTs include optical and microdialysis methods. Finally, we show the advantages and disadvantages of different techniques and conclude remarks with future perspectives.

By addressing precursor prevalence and energetics using the DFT-based synthetic growth concept (SGC), the formation mechanism of self-induced InAlN core–shell nanorods (NRs) synthesized by reactive magnetron sputter epitaxy (MSE) is explored. The characteristics of In- and Al-containing precursor species are evaluated considering the thermal conditions at a typical NR growth temperature of around 700 °C. The cohesive and dissociation energies of In-containing precursors are consistently lower than those of their Al-containing counterparts, indicating that In-containing precursors are more weakly bonded and more prone to dissociation. Therefore, In-containing species are expected to exhibit lower abundance in the NR growth environment. At increased growth temperatures, the depletion of In-based precursors is even more pronounced. A distinctive imbalance in the incorporation of Al- and In-containing precursor species (namely, AlN/AlN⁺, AlN₂/AlN₂⁺, Al₂N₂/Al₂N₂⁺, and Al₂/Al₂⁺ vs InN/InN⁺, InN₂/InN₂⁺, In₂N₂/In₂N₂⁺, and In₂/In₂⁺) is found at the growing edge of the NR side surfaces, which correlates well with the experimentally obtained core–shell structure as well as with the distinctive In-rich core and vice versa for the Al-rich shell. The performed modeling indicates that the formation of the core–shell structure is substantially driven by the precursors’ abundance and their preferential bonding onto the growing edge of the nanoclusters/islands initiated by phase separation from the beginning of the NR growth. The cohesive energies and the band gaps of the NRs show decreasing trends with an increment in the In concentration of the NRs’ core and with an increment in the overall thickness (diameter) of the NRs. These results reveal the energy and electronic reasons behind the limited growth (up to ∼25% of In atoms of all metal atoms, i.e., In_xAl_1–xN, x ∼ 0.25) in the NR core and may be qualitatively perceived as a limiting factor for the thickness of the grown NRs (typically <50 nm).