Next Nanotechnology最新文献

Nanorobots with advanced capabilities that can accomplish various tasks have been the focus of significant research interests. Nanorobots can self-propel in different trajectories, be guided using external fields, and interact with objects and the environment. In recent years, various fabrication techniques, such as physical, chemical, microfluidic, and self-assembly methods, have been employed to integrate specific functions. Microfluidic platforms are utilized to encapsulate individual reactions and reaction networks, providing an experimental testbed system for designing the next generation of nanorobots. Due to significant progress in the field, man-made nanobots have been applied for a wide variety of operations. Today, a convergence between biomedical nanoparticles and nanorobots is apparent. This review discusses the next generation of nanorobots, the range of their fabrication techniques, and introduces integrated functions for bio-applications.

Prostate-specific antigen (PSA), is a protein produced by cancerous cells in the prostate gland, and its presence may indicate the likelihood of prostate cancer. For the purpose of detecting PSA, an innovative aptasensor utilizing magnetic sulfonated reduced graphene oxide/gold nanoparticles was developed. This unique nanocomposite has been used for the first time for biosensing of prostate cancer which resulted in significant enhancement of the biosensor’s performance. Unlike previous works, our biosensor incorporates two detection modes: a label-free detection mode in ferrocyanide solution and a labeled mode using methylene blue. Different tests such as FTIR, XRD and TEM were applied to recognize the characterization of the nanoparticles and to make sure of the linkage of particles. To examine the aptasensor at various stages, a range of electroanalytical techniques, such as cyclic voltammetry (CV), square-wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS), were employed. The aptasensor exhibited significant selectivity for PSA, as demonstrated by its ability to distinguish PSA from other components like glucose, carcinoembryonic antigen (CEA), etc. Ultimately, the detection limit (LOD) reached 1.371 ng/mL in the ferrocyanide environment with an R² value of 0.9777. Furthermore, the labeled electrode in phosphate buffer achieved the remarkable detection limit of 1.566 pg/mL with an R² value of 0.9676 and linear range of 2.5–12.5 pg/mL, demonstrating the impressive sensitivity and accuracy of the method.

Supercapacitors are energy storage devices that, in contrast to classical capacitors, are able to deliver larger amounts of energy keeping a fast charge/discharge rates. They can be considered as the meeting point between batteries and classical capacitors. Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) is one of the most used conductive polymers (CPs) due to its high thermal stability, low electronic resistance and its ease of application. The role of PEDOT:PSS in supercapacitors where it substitutes the liquid electrolyte is a very interesting approach. Not only it results in a better performing but also a safer option than classical electrolytic capacitors. Despite their wide use in this type of devices, the charge storage mechanism of a PEDOT:PSS layer is still not fully understood. When they were conceived, CPs were automatically classified as pseudocapacitors in terms of their capacitive properties. However, recent analysis of the characteristics of PEDOT:PSS has challenged the origin of the capacitive properties. The mixed ionic-electronic conductivity as a result of the two phases present in PEDOT:PSS (PEDOT rich regions and PSS rich regions) translates into the formation of multiple capacitors in the nanometric scale. These contribute to the total capacitance and they resemble the capacitive mechanism of electrochemical double layers capacitors (EDLC). The combination of PEDOT:PSS with the enlarged surface area of a valve metal such as aluminium gives rise to a solid-state polymer capacitor with low equivalent series resistance (ESR), high capacitance and safer operation conditions than the liquid counterparts. This review covers the recent literature on the main two groups of supercapacitors, namely EDLC and pseudocapacitors, and positions PEDOT:PSS according to the latest findings. Additionally, it presents the challenges of achieving the optimal combination of PEDOT:PSS and aluminium towards better solid-state polymer capacitors at the nanoscale.

When the catalyst size decreases down to the nanometer or even sub-nanometer scale, their geometric and electronic structures are very different from the bulk materials. Especially, their structural dynamics can greatly affect catalytic performances. Herein, we report a theoretical study on oxygen dissociation on Ag₁₉ cluster, a critical step of ethylene epoxidation, to investigate the effect of structural dynamics on the catalytic activity. Combining ab initio molecular dynamics (AIMD) and free energy calculation, we obtain the free energy profiles under different temperatures and find sudden drops in the reaction free energy and barrier at certain temperature ranges. The reaction entropy change shows a positive peak because of the different melting temperatures between initial and final states. Additionally, we further investigate the oxygen diffusion process on the Ag cluster and compare it with the Au and Cu clusters. We find that weak adsorption of oxygen on the silver cluster leads to its facile diffusion and thus reduces the melting temperature of the cluster, therefore facilitating partial oxidation under mild conditions.

Room-temperature sodium-sulfur (RT Na-S) batteries have attracted considerable research interests in the past years, due to their advantages in natural resources, materials cost, specific capacity, and energy density etc.; however, they are suffering from various threats from S cathodes, encompassing shuttle effect, low electronic conductivity, volume change, and sluggish kinetics etc. Transition metal sulfides are demonstrated as promising redox regulators to help tackle these key issues as a result of their excellent chemical affinity and/or catalytic ability and improve the overall performance of RT Na-S batteries. Herein, the recent advances in rational design of the mainstream transition metal sulfides for RT Na-S batteries are comprehensively reviewed, including cobalt sulfides, iron sulfides, nickel/zinc sulfides, molybdenum sulfides, and their heterostructures. The emphasis is on fundamental properties of these sulfides, interactions between metal sulfides and polysulfides, materials design strategies and electrochemical performance. Potential developmental directions are also put forward to promote the further progress on RT Na-S batteries.

Given the poor conductivity of reactants/products and the serious lithium polysulfide shuttle effect, chemical kinetic inhibition, as well as indisciplinable growth of lithium metal dendrites, the design of lithiophilicity-sulfiphilicity hosts is key to solving the problems associated with both sulfur and lithium electrodes in practical Li-S batteries. Herein, a multifunctional self-supporting scaffold (PVDF/C fiber/BN) composed of different electrospun fibers is rationally designed, which can simultaneously address the challenges of Li anodes and S cathodes. The 3D integrated scaffold has a highly promising lithiophilic-lithiophobic gradient interfacial layer, which can efficiently restrain Li dendrites growth and guarantee ultralong and stable Li plating/stripping. Furthermore, the abundant polar functional groups can provide synergistic functions such as physical restraint, chemical adsorption, and excellent electrocatalysis for LiPSs conversion. Combining these advantages, the Li-S full battery (S/PVDF/C fiber/BN || Li/PVDF/C fiber/BN) exhibits remarkable electrochemical performance, including an excellent discharge capacity of 953.3 mAh g⁻¹ after 200 cycles at 0.5 A g⁻¹. The designed full battery also delivers significant areal capacity (4.37 mAh cm⁻² at 0.1 A g⁻¹) even with a high loading of 6 mg cm⁻². This work lays down new design ideas for making dendrite-free, high-performance Li-S full batteries.

The present paper deals with the preparation of 2D material dispersions using a mixture of solvents that mimics whiskey. According to the Hansen’s model, we obtained the best solvent applying a design of experiment (DoE) approach to the components present in the whiskey, as reported in literature, in order to obtain a less hazardous and green solvent. The DoE approach was also applied in the exfoliation procedure, in order to maximize the exfoliation and stability of dispersions. We obtained dispersions with a stability lasting longer than nine months in the best case. After the electrical characterization, we deposited the dispersion onto an interdigitated device in order to obtain a moisture sensor. The device showed a sensitivity due to a negative response of sensing (Grotthuss mechanism). The DC characterization showed a good response in the range 50–95% in low voltage regime (up to 3 V). The impedance spectroscopy confirms this hypothesis: the evolution of the Nyquist plot when increasing the relative humidity suggests the intercalation of water molecules among the nanoparticles.

With the development of surface acoustic wave (SAW) technology, SAW devices have been widely applied in various areas, especially in optoelectronics fields. Compared with traditional optoelectronic devices, SAW devices exhibit higher sensitivity and can realize passive wireless operating. Although previously reported optoelectronic applications of the SAW mainly focused on ultraviolet wavelengths, recent years have witnessed its potential in visible and infrared wavelengths. In this review, the optoelectronic devices and applications of the SAW in visible and infrared wavelengths, especially on photodetection and photoelectric modulation, are introduced in detail. The research status of these devices are analyzed emphatically, including their structures, working principles, key parameters, acoustic wave types, material compositions, and performances. Finally, the future challenges and upcoming perspectives of SAW optoelectronic applications in the visible and infrared wavelengths are discussed.

Immunotherapy, although effective, may have a low response rate and off-target toxicity when used to boost the immune system in cancer treatment. However, the use of nanomaterials has revolutionized cancer treatment by enabling precise drug delivery, improving the efficacy of cancer vaccines, and manipulating the immune activity of macrophages and T cells.