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Cell-Penetrating Peptides Transport Noncovalently Linked Thermally Activated Delayed Fluorescence Nanoparticles for Time-Resolved Luminescence Imaging
摘要： Luminescent probes and nanoparticles (NPs) with long excited state lifetimes are essential for time-resolved biological imaging. Generally, cell membranes are physiological barriers that could prevent the uptake of many unnatural compounds. It is still a big challenge to prepare biocompatible imaging agents with high cytomembrane permeability, especially for nonmetallic NPs with long-lived luminescence. Herein, an amphiphilic cell-penetrating peptide, F6G6(rR)3R2, was designed to transport hydrophobic fluorophores across cellular barriers. Three classical thermally activated delayed fluorescence (TADF) molecules, 4CzIPN, NAI-DPAC, and BTZ-DMAC, could self-assemble into well-dispersed NPs with F6G6(rR)3R2 in aqueous solution. These NPs showed low cytotoxicity and could penetrate membranes easily. Moreover, long-lived TADF enabled them to be used in time-resolved luminescence imaging in oxygenic environments. These findings greatly expanded the applications of cell-penetrating peptides for delivery of molecules and NPs by only noncovalent interactions, which were more flexible and easier than covalent modifications.
关键词： cell-penetrating peptide,Luminescent probes,time-resolved biological imaging,nanoparticles,noncovalent interactions,thermally activated delayed fluorescence
更新于2025-09-04 15:30:14
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Preparation and Comparison of Magnetic Nanoparticles and Magnetic Nanoparticles Doped with Cobalt for Photodegradation of Methyl Orange
摘要： This paper describes a study in which magnetic nanoparticles were fabricated via co-precipitation approach. These nanoparticles were then coated with cobalt as a means of enhancing their photocatalytic activity. A variety of different instruments were used to characterize the magnetic nanoparticles including transmission electron microscopy, X-ray diffraction analysis, and scanning electron microscope. They were then tested to determine the extent to which they could effectively degrade harmful dyes in the form of was methyl orange under UV lamp irradiation (365 nm). The performance of standard magnetic nanoparticles was compared with those coated with cobalt in terms of removal of methyl orange to determine the extent to which Co-doped magnetic nanoparticles can more effectively facilitate the photocatalytic degradation of methyl orange in comparison to standard magnetic nanoparticles.
关键词： Nanoparticles,Photocatalyst,Photocatalytic degradation,Methyl orange,Co-doped Fe3O4
更新于2025-09-04 15:30:14
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Specific Targeting of Breast Cancer Cells with Antibodies Conjugated Gold Nanoparticles
摘要： Background and Objective: Gold nanoparticles (AuNP) conjugated with either EpCAM or TARP antibodies and an anticancer agent, paclitaxel (PTX), for tumour targeting and therapy were synthesised using a simple chemistry. Methods: The AuNP surface was functionalised using a two-step modification approach. The conjugates were characterised using Transmission Electron Microscopy (TEM) and infrared spectroscopy. Results: The cytotoxicity assay of T47D cells treated with only antibodies conjugated to the gold nanoparticles did not show any cytotoxicity to the cells, which indicates these nanoconjugates are suitable for intracellular delivery of anticancer drugs. Conclusion: When using AuNPs with antibodies and the cancer chemotherapy agent PTX attached simultaneously to the functionalised AuNPs, the reduction of cell viability was significantly higher compared to PTX-thiol-AuNPs conjugate system where no antibodies were used.
关键词： drug delivery,antibodies,paclitaxel,EpCAM,Gold nanoparticles,TARP,cytotoxicity
更新于2025-09-04 15:30:14
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Comparative Measurements of Photoelectron Emission in Bulk Samples and Island Films of Silver
摘要： The photoelectron emission has been studied of silver island films excited by a laser pulse of 10-ns duration at three wavelengths: 355, 532, and 1064 nm. It has been shown that, for wavelengths of 355 and 532 nm, the photoemission of island films significantly differs from the photoemission of a bulk sample. For an island film, dependence on the pulse energy characteristic for single-photon emission has been observed at a 355-nm wavelength. It has also been shown that the surface plasmon resonance in nanoparticles significantly affects the photoemission and character of its dependence on the energy of the laser pulse.
关键词： laser pulse,photoelectron emission,nanoparticles,silver island films,surface plasmon resonance
更新于2025-09-04 15:30:14
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Synthesis of Fluorescent Core-Shell Metal Nanohybrids: A Versatile Approach
摘要： A ?exible way of fabricating core-shell noble metal-organic nanohybrids with tailored chemical and spectroscopic properties is proposed here. The synthetic protocol consists of a multi-step procedure able to guarantee acceptable reproducibility of core size and shape as well as control of the organic outer layer. The proposed method highlights limitations in obtaining highly controllable products, although the heterogeneity degree of the nanostructures is in line with that expected from bottom-up approaches in solution. Selective functionalization of the nanohybrids with properly-substituted ?uorescent dyes under variable experimental conditions allowed the preparation of composite systems of tunable spectroscopic properties to be employed as nanoprobes in sensing or photonic applications. To this end, preliminary investigation on embedding the nanohybrids in compatible polymeric matrices is also reported.
关键词： polymeric matrix,spectroscopic properties,core-shell architecture,noble metal nanoparticles,self-assembly
更新于2025-09-04 15:30:14
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Thin Film Processes - Artifacts on Surface Phenomena and Technological Facets || Layer-by-Layer Thin Films and Coatings Containing Metal Nanoparticles in Catalysis
摘要： The layer-by-layer (LbL) technique is one of the most promising ways of fabricating multilayer thin films and coatings with precisely controlled composition, thickness, and architecture on a nanometer scale. This chapter considers the multilayer thin films and coatings containing metal nanoparticles. The main attention was paid to LbL films containing metal nanoparticles assembled by convenient methods based on the different intermolecular interactions, such as hydrogen bonding, charge transfer interaction, molecular recognition, coordination interactions, as driving force for the multilayer buildup. Much attention has paid to the LbL films containing metal nanocomposites for multifunctional catalytic applications, in particular, photocatalysis, thermal catalysis, and electrocatalysis. The preparation protocol of LbL-assembled multilayer thin films containing metal nanoparticles (such as Au, Ag, Pd, Pt), metal oxides (Fe3O4), and sulfides (CdS) that are supported on the various surfaces of nanotubes of TiO2, Al2O3 membranes, graphene nanosheets, graphene oxide and further applications as catalysts with respect to photocatalytic, electrocatalytic performances is discussed. The systematization and analysis of literature data on synthesis, characterization, and application of multilayer thin films and coatings containing metal nanoparticles on the diverse supports may open new directions and perspectives in this unique and exciting subject.
关键词： semiconductors,metal nanoparticles,polyelectrolytes,layer-by-layer assembling,thin films and coatings,immobilization,catalysts
更新于2025-09-04 15:30:14
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Silver-Nanowire-Based Interferometric Optical Tweezers for Enhanced Optical Trapping and Binding of Nanoparticles
摘要： Light-induced self-assembly offers a new route to build mesoscale optical matter arrays from nanoparticles (NPs), yet the low stability of optical matter systems limits the assembly of large-scale NP arrays. Here it is shown that the interferometric optical fields created by illuminating a single Ag nanowire deposited on a coverslip can enhance the electrodynamic interactions among NPs. The Ag nanowire serves as a plasmonic antenna to shape the incident laser beam and guide the optical assembly of colloidal metal (Ag and Au) and dielectric (polystyrene) NPs in solution. By controlling the laser polarization direction, both the mesoscale interactions among multiple NPs and the near-field coupling between the NPs and nanowire can be tuned, leading to large-scale and stable optical matter arrays consisting of up to 60 NPs. These results demonstrate that single Ag nanowires can serve as multifunctional antennas to guide the optical trapping and binding of multiple NPs and provide a new strategy to control electrodynamic interactions using hybrid nanostructures.
关键词： self-assembly,colloidal nanoparticles,optical binding,interferometric optical tweezers
更新于2025-09-04 15:30:14
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Selective recognition of Cr (VI) ion as Cr <sub/>2</sub> O <sub/>7</sub><sup>2?</sup> in aqueous medium using CTAB‐capped anthracene‐based nanosensor: Application to real water sample analysis
摘要： Surfactant‐capped nanoparticles of 9, 10‐diphenyl anthracene prepared by reprecipitation method found highly fluorescent due to aggregation‐induced enhanced emission (AIEE). Cetyltrimethyl ammonium bromide (CTAB) surfactant not only generated positive zeta potential on the surface of nanoparticles to attract anions of interest but also stabilized nanoparticles into brick‐shape morphology. The fluorescence of nanoparticles is quenched by Cr2O7 ion very significantly in comparison with other diverse ions, namely, MnO4, S2O8 showed increase in the fluorescence of nanoparticles, the interference found is negligible in the Cr (VI) analysis. The selectivity and sensitivity of nanoparticles for recognition of Cr2O7 were explored by systematic fluorescence titration. The fluorescence quenching data fits into the usual Stern‐Volmer equation. A calibration curve constructed by plotting quenching of fluorescence (ΔF) against concentration of Cr (VI) exhibiting a linear fit in the equation, ΔF = 3070x, is used for the estimation of chromium concentration (x). The correlation coefficient value R2 = 0.998 obtained from curve is nearly equal to 1 indicates linear fit between quenching data and concentration of Cr (VI). The estimated values of limit of detection (LOD) in the method 0.01392 μg.mL?1 is far below the permissible value of Cr (VI) 0.05 μg.mL?1 in drinking water approved by world health organization (WHO) and United State Environmental Protection Agency (USEPA). The proposed method of Cr (VI) detection is applied for real sample collected from hard chrome deposition industry from nearby region. The amount of Cr (VI) estimated by present method is comparable with AAS determination for the same samples.
关键词： Diphenylanthracene nanoparticles,Cr (VI) ion,CTAB,aggregation induced enhanced emission,electrostatic interaction
更新于2025-09-04 15:30:14
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Raman and Surface-Enhanced Raman Scattering for Biofilm Characterization
摘要： Bio?lms are a communal way of living for microorganisms in which microorganism cells are surrounded by extracellular polymeric substances (EPS). Most microorganisms can live in bio?lm form. Since microorganisms are everywhere, understanding bio?lm structure and composition is crucial for making the world a better place to live, not only for humans but also for other living creatures. Raman spectroscopy is a nondestructive technique and provides ?ngerprint information about an analyte of interest. Surface-enhanced Raman spectroscopy is a form of this technique and provides enhanced scattering of the analyte that is in close vicinity of a nanostructured noble metal surface such as silver or gold. In this review, the applications of both techniques and their combination with other bio?lm analysis techniques for characterization of composition and structure of bio?lms are discussed.
关键词： Raman spectroscopy,surface-enhanced Raman spectroscopy,biofilm,nanoparticles,bacteria
更新于2025-09-04 15:30:14
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Tuning the Surface Plasmon Resonance of Lanthanum Hexaboride to Absorb Solar Heat: A Review
摘要： While traditional noble metal (Ag, Au, and Cu) nanoparticles are well known for their plasmonic properties, they typically only absorb in the ultraviolet and visible regions. The study of metal hexaborides, lanthanum hexaboride (LaB6) in particular, expands the available absorbance range of these metals well into the near-infrared. As a result, LaB6 has become a material of interest for its energy and heat absorption properties, most notably to those trying to absorb solar heat. Given the growing popularity of LaB6, this review focuses on the advances made in the past decade with respect to controlling the plasmonic properties of LaB6 nanoparticles. This review discusses the fundamental structure of LaB6 and explains how decreasing the nanoparticle size changes the atomic vibrations on the surface and thus the plasmonic absorbance band. We explain how doping LaB6 nanoparticles with lanthanide metals (Y, Sm, and Eu) red-shifts the absorbance band and describe research focusing on the correlation between size dependent and morphological effects on the surface plasmon resonance. This work also describes successes that have been made in dispersing LaB6 nanoparticles for various optical applications, highlighting the most difficult challenges encountered in this field of study.
关键词： heat absorption,nanoparticles,plasmon,LaB6,lanthanum hexaboride
更新于2025-09-04 15:30:14