Nanoscale Advances最新文献

Addressing the pressing need to develop affordable and efficient catalysts is essential. In this study, we successfully synthesized Cu₃BiS₃ nanostructures with a modified morphology using three different nitrogen bases: DBN, DBU, and DABCO via a hydrothermal technique. These nanostructures were used for the electrochemical detection of organic nitro groups, a previously unexplored application for this material. We conducted a thorough characterization of the Cu₃BiS₃ nanostructures using various analytical and spectroscopic methods, including PXRD, FESEM, TEM, XPS, UV-vis, and BET, ensuring the reliability of our results. We then investigated their performance in the electrochemical detection of 4-dinitrophenol (4-NP) and 2,4-dinitrophenol (2,4-DNP) using a modified glassy carbon (GC) electrode. The Cu₃BiS₃ material produced using DABCO exhibited better sensitivity towards 4-NP detection, with a low limit of detection (LOD) of 0.50 μM compared to the ones synthesized using DBN and DBU. Furthermore, the synthesized materials demonstrated the ability to detect their structural analogue, 2,4-DNP. The distinctive hierarchical nanostructures attained in Cu₃BiS₃ highlight the benefits of developing such catalysts and the impact of nitrogenous bases in defining the morphology of the materials with enhanced catalytic activities.

Carbon nanomaterials (CNMs), such as carbon nanotubes (CNTs), graphene quantum dots (GQDs), and carbon quantum dots (CQDs), are prevalent in biological systems and have been widely utilized in applications like environmental sensing and biomedical fields. While their presence in human matrices is projected to increase, the interfacial interactions between carbon-based nanoscopic platforms and biomolecular systems continue to remain underexplored. In this study, we investigated the effect of gelatin-sourced CQDs on the globular milk protein beta-lactoglobulin (BLG). Exposure to the CQDs resulted in the disruption of BLG's tertiary and secondary structural elements (transformation of isolated helices to coiled-coils and increased beta-sheet content), with IR amide backbone signatures further confirming CQD-induced alterations in protein structures. Importantly, the structural perturbations induced by CQDs compromised BLG : retinol interactions, potentially affecting its physiological ligand transport function. By contrast, cytotoxicity analyses revealed a high viability of neuroblastoma cells exposed to this CNM, suggesting biomolecule-specific effects. Collectively, the data reveal aberrant molecular and functional consequences associated with the interactions of a globular protein with an otherwise biocompatible CQD. In conclusion, this work represents the initial steps toward a comprehensive understanding at the atomic and molecular levels of the outcomes linked to the utilization of carbon-based nanomaterials and their potential adverse systemic consequences.

In an effort to meet the high demand for silver nanostructures in both research and consumer applications, we devise a simple and readily scaleable photochemical method through which silver nanostructures of varying morphologies, sizes, and optical properties can be synthesized using batch and flow photochemical strategies. For the latter we build upon the application of a wrapped-lamp photochemical flow system recently developed by our group to enable sequential irradiation with several wavelengths of LEDs in series in an approach that we describe as "plasmon pushing". We find that this strategy can accelerate the conversion of silver nanoparticle seeds to decahedral and triangular nanostructures, and that with it we have control over the tuning of the size and optical properties of triangular nanostructures in the red and near-IR regions. Moreover, through sequential flow irradiation, we gain a better understanding of the formation pathways and relative stability of decahedral and triangular silver nanostructures.

We proposed an ingenious, highly efficient TiO₂ meta-atom (MA)-based near-infrared disordered metalens structure harnessing bird's eye-inspired hyperuniform distribution and analyzed its optical and imaging properties employing the finite-difference time-domain (FDTD) method. The hyperuniform disordered MAs constructed an image at a focal length by engineering the phase shift of transmittance. We obtained a high focusing efficiency of 84.39% at a wavelength of 820 nm for disordered metalens structures. Amazingly, our proposed disordered metalens structures can mimic the optical properties of ordered metalens structures. Similar focusing efficiencies of disordered and ordered metalens structures were found in a wavelength range from 850 to 890 nm due to the long-range periodic properties of hyperuniform disordered structures. The focal length shifts and NAs of disordered metalens structures were comparable to the focal length shifts and NAs of periodic metalens structures in the entire operating region from 770 to 970 nm with a constant FWHM of 1.503 μm. Our proposed structure paves the way for designing new and innovative imaging, sensing, and spectroscopic technologies, such as lidar, medical devices, IR and machine vision cameras, display systems, and holography.

Nanocrystals are widely explored for a range of medical, imaging, sensing, and energy conversion applications. CdS nanocrystals have been reported as excellent photocatalysts, with thin film CdS also highly important in photovoltaic devices. To optimise properties of nanocrystals, control over phase, facet, and morphology are vital. Here, CdS nanocrystals were synthesised by the solvothermal decomposition of a Cd xanthate single source precursor. To attempt to control CdS nanocrystal surfaces and morphology, the solvent used in the nanocrystal synthesis was altered from pure trioctylphosphine oxide (TOPO) to a mixed TOPO : fluorinated aromatic amine (3-fluorobenzyl amine (3-FlBzAm) or 3-fluoroaniline (3-FlAn)), where ¹⁹F provides a sensitive NMR-active surface probe. Powder X-ray diffraction found that the CdS nanocrystals synthesised from TOPO : 3-FlAn solvent mixtures were predominantly cubic whilst the TOPO : 3-FlBzAm synthesised nanocrystals were predominantly hexagonal. Raman spectroscopy identified hexagonal CdS in all samples. Solid-state NMR of ¹¹³Cd, ¹⁹F, ¹³C, and ¹H was employed to investigate the local Cd environments, surface ligands, and ligand interactions. This showed there was a mixture of CdS phases present in all samples and that surfaces were capped with TOPO : fluorinated aromatic amine mixtures, but also that there was a stronger binding affinity of 3-FlBzAm compared with 3-FlAn on the CdS surface, which likely impacts growth mechanisms. This work highlights that fluorinated aromatic amines can be used to probe NC surfaces and also control NC properties through their influence during NC growth.

Here, a straightforward design is employed to synthesize a nanocatalyst based on a carbon-activated modified metal-organic framework using the solvothermal method. This work presents a simple and practical approach for producing the activated carbon derived from the Thymus plant (ACT) modified with amine-functionalized isoreticular metal-organic framework-3 (IRMOF-3) to create an ACT@IRMOF-3 core-shell structure. Successful functionalization was confirmed through N₂ adsorption isotherms, FT-IR, FE-SEM, TEM, EDS, elemental mapping, TGA, and XRD analysis. The ACT@IRMOF-3 nanocomposite demonstrated exceptional performance in the synthesis of novel benzodiazepine derivatives, facilitating high product yields using various 1,2-phenylenediamine and aromatic aldehydes under mild conditions. The obtained results demonstrated that the presence of IRMOF-3 on the surface of ACT remarkably increases the catalytic reaction yield. The present methodology offers several merits such as high catalytic activity, excellent yields, short reaction times, cleaner reactions, simple operations, and compatibility of a wide range of substrates. Furthermore, the catalyst can be easily isolated from the reaction mixture via filtration and retains remarkable reusability and catalytic activity even after six consecutive reaction cycles.

In this study, we introduce an in situ synthesis technique for incorporating gold nanoparticles (AuNPs) into a magnetic nanocomposite made of glucosamine and alginate (GluN/Alg) via ionotropic gelation. GluN acted as a reducing agent for gold ions, leading to the formation of AuNPs which embedded in the nanocomposite Fe₃O₄@GluN/Alg. Analytical techniques confirmed the crystallite structure of the nanocomposite AuNPs/Fe₃O₄@GluN/Alg, which had an average size of 30–40 nm. This nanocomposite demonstrated high catalytic efficiency in reducing 2-, 3-, and 4-nitrophenols, exhibiting rapid kinetics with pseudo-first order rate constants between 1.16 × 10⁻³ s⁻¹ and 2.29 × 10⁻³ s⁻¹. The reduction rates and recyclability for nitrophenols followed the order: 4-nitrophenol > 2-nitrophenol ∼ 3-nitrophenol. These results indicate that the nanocomposite holds significant promise for customized applications in environment and medicine, positioning it as a highly versatile material.

Surface-enhanced Raman spectroscopy (SERS) has shown its ability to characterize biological substances down to a single-molecule level without a specific biorecognition mechanism. Various nanofabrication technologies enable SERS substrate prototyping and mass manufacturing. This study reports a complete cycle of design, fabrication, prototyping, and metrology of SERS substrates based on two-photon polymerization (2PP). Highly controllable direct laser writing allows the fabrication of individual nanopillars with up to an aspect ratio of 4. The developed SERS substrates show up to 10⁶ Raman signal enhancement, comparable to commercial substrates. Moreover, the rapid prototyping of the 2PP-printed SERS substrates takes from a minute to less than 2 hours, depending upon the nano-printing approach and aspect ratio requirements. The process is well-controlled and reproducible for achieving a uniform distribution of nanostructure arrays, allowing the SERS substrates to be used for a broad range of applications and the characterization of different molecules.

The potential applicability of the C₂₄ nanocage and its boron nitride-doped analogs (C₁₈B₃N₃ and C₁₂B₆N₆) as pyrazinamide (PA) carriers was investigated using density functional theory. Geometry optimization and energy calculations were performed using the B3LYP functional and 6-31G(d) basis set. Besides, dispersion-corrected interaction energies were calculated at CAM (Coulomb attenuated method)-B3LYP/6-31G(d,p) and M06-2X/6-31G(d,p) levels of theory. The adsorption energy (E _ads), enthalpy (ΔH), and Gibbs free energy (ΔG) values for C₂₄-PA, C₁₈B₃N₃-PA, and C₁₂B₆N₆-PA structures were calculated. The molecular descriptors such as electrophilicity (ω), chemical potential (μ), chemical hardness (η) and chemical softness (S) of compounds were investigated. Natural bond orbital (NBO) analysis confirms the charge transfer from the drug molecule to nanocarriers upon adsorption. Based on the quantum theory of atoms in molecules (QTAIM), the nature of interactions in the complexes was determined. These findings suggest that C₂₄ and its doped analogs are promising candidates for smart drug delivery systems and PA sensing applications, offering significant potential for advancements in targeted tuberculosis treatment.

With advancements in photonic technologies, photonic crystal fibers (PCFs) have become crucial components in developing highly sensitive and efficient biosensors. This paper presents an optimized bowtie-shaped PCF biosensor that leverages surface plasmon resonance (SPR) phenomena for enhanced refractive index (RI) sensing. The proposed design uses an external sensing mechanism to effectively characterize performance across an RI range of 1.32 to 1.44. Fabrication is simplified by selecting a large pitch and gold layer height, while performance is enhanced by increasing pitch size, improving the gold layer, and optimizing air hole diameter. Simulations performed using the finite element method in COMSOL Multiphysics v5.4 demonstrate an impressive wavelength sensitivity (WS) of 143 000 nm per RIU and an amplitude sensitivity (AS) of 6242 per RIU. The sensor also exhibits a high resolution of 6.99 × 10⁻⁷ RIU and maintains excellent full width at half maximum (FWHM) characteristics, resulting in a very high figure of merit (FOM) of 2600, indicating superior performance. These promising results suggest that the optimized bowtie-shaped PCF biosensor can be effectively applied to detect a wide range of biological and chemical substances with high precision and sensitivity.