A Surface‐Charge Study on Cellular‐Uptake Behavior of F3‐Peptide‐Conjugated Iron Oxide Nanoparticles

Surface‐charge measurements of mammalian cells in terms of Zeta potential are demonstrated as a useful biological characteristic in identifying cellular interactions with specific nanomaterials. A theoretical model of the changes in Zeta potential of cells after incubation with nanoparticles is established to predict the possible patterns of Zeta‐potential change to reveal the binding and internalization effects. The experimental results show a distinct pattern of Zeta‐potential change that allows the discrimination of human normal breast epithelial cells (MCF‐10A) from human cancer breast epithelial cells (MCF‐7) when the cells are incubated with dextran coated iron oxide nanoparticles that contain tumor‐homing F3 peptides, where the tumor‐homing F3 peptide specifically bound to nucleolin receptors that are overexpressed in cancer breast cells.     

Effect of Magnetized Ethanol on the Shape Evolution of Zinc Oxide from Nanoparticles to Microrods: Experimental and Molecular Dynamic Simulation Study

In the current research, ethanol was exposed to an external magnetic field, called magnetized ethanol, and then, used as a solvent in the solvothermal method to synthesize various ZnO structures. Moreover, the morphologies of the synthesized structures are compared with those obtained using ordinary ethanol. The attained results evidently demonstrated the formation of ZnO nanoparticles and microrods by using ordinary and magnetized ethanol, respectively. Moreover, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were utilized for characterizing the synthesized ZnO structures. The XRD results demonstrated that the synthesized products are in Zincite hexagonal phase. Besides, molecular dynamics simulation suggested that the molecular mobility is diminished upon using the magnetic field. It was found that the interactions among ZnO particles were enhanced by the slight increase in the magnetic field while the number of interactions between ZnO and solvent was reduced revealing the magnetic-field-induced particle growth from the molecular level insight.     

Understanding the Enhancement Mechanisms of Surface Plasmon‐Mediated Photoelectrochemical Electrodes: A Case Study on Au Nanoparticle Decorated TiO2 Nanotubes

Surface plasmon resonance (SPR) enhancement in photocatalyst and photovoltaics has been widely studied and different enhancement mechanisms have been established based on different heterostructure interface configurations. This work is intended to unveil the mechanisms behind charge or energy transfer in different plasmonic configurations of metal particle–semiconductor interfaces, especially with a dielectric layer. For this purpose, a series of composite photoelectrodes based on anodic TiO₂ nanotube (TONT) backbones coated with Au, Al₂O_3, or both are designed and characterized systematically. In conjunction with both experimental measurements and numerical simulations, it is revealed that in the TONT‐Al₂O₃‐Au electrode system (i.e., a thin nonconductive spacer between semiconductor and metal), the enhancement is dominantly governed by SPR‐mediated hot‐electron injection rather than conventional‐thought near‐field electromagnetic enhancement. Among all configurations, the TONT‐Au‐Al₂O₃ electrode shows the best photoresponse in both UV and visible regions. The superior visible light response of the TONT‐Au‐Al₂O₃ electrode is ascribed to the Al₂O₃ intensified local electromagnetic field that enhances the hot‐electron injection through the TiO₂‐Au interface, and an effective surface passivation by the Al₂O₃ coating.