Photochromic transparent wooden materials are highly critical and attractive for smart windows, which have been scarcely investigated. In this context, we develop photochromic and fluorescent translucent wood with a color switching ability in the UV and visible spectrum regions, which is associated with color shifting properties. The fluorescent and photochromic translucent wood were generated by permeating a lignin-modified wooden substrate using a formulation containing methyl methacrylate (MMA) and a photoluminescent lanthanide-doped aluminum strontium oxide (SrAl2O4:Eu2+, Dy3+; ASOED) pigment characterized by good photo- and thermal stability. For a better preparation of photoluminescent transparent wood, the ASOED phosphor must be efficiently dispersed without aggregation in pre-polymerized MMA. This translucent wooden substrate demonstrated a color change from colorless in visible light to green under irradiation with UV as designated by CIE Lab colorimetric results. The morphological characteristics of the generated pigment nanoparticles (NPs) were studied using transmission electron microscopic micrographs. Scanning electron microscopy, elemental mapping, energy-dispersive X-ray spectroscopic analysis, wavelength-dispersive X-ray fluorescence spectroscopy, and hardness properties, in addition to UV–vis absorption and emission spectroscopy of the photochromic translucent wood samples, were used. The prepared photoluminescence transparent wood showed an absorption signal at 365 nm and two emission signals at 433 and 517 nm. The findings demonstrated that the generated transparent luminescent wood exhibited improved UV protection and superhydrophobic activity. The produced transparent luminescent wood showed fast and reversible photochromic responses to UV light without fatigue.

The use of programmed electrical signals to influence biological events has been a widely accepted clinical methodology for neurostimulation. An optimal biocompatible platform for neural activation efficiently transfers electrical signals across the electrode–cell interface and also incorporates large-area neural guidance conduits. Inherently conducting polymers (ICPs) have emerged as frontrunners as soft biocompatible alternatives to traditionally used metal electrodes, which are highly invasive and elicit tissue damage over long-term implantation. However, fabrication techniques for the ICPs suffer a major bottleneck, which limits their usability and medical translation. Herein, we report that these limitations can be overcome using colloidal chemistry to fabricate multimodal conducting polymer nanoparticles. Furthermore, we demonstrate that these polymer nanoparticles can be precisely assembled into large-area linear conduits using surface chemistry. Finally, we validate that this platform can act as guidance conduits for neurostimulation, whereby the presence of electrical current induces remarkable dendritic axonal sprouting of cells.

A simple method for the preparation of multifunctional nanocomposite was developed towards the production of water-repellent, electrically conductive, and photoluminescent film onto cotton fibres. The nanocomposite was composed of lanthanide-doped strontium aluminium oxide and silicon rubber dispersed in petroleum ether. The electrically conductive fabric was woven from nickel strips twisted with cotton filaments as core yarns, which were wrapped with pure cotton yarns. The nanoparticles (NPs) of lanthanide-doped strontium aluminium oxide were mixed with environmentally friendly room-temperature vulcanizing silicon rubber (RTV-SR) dis-

Randomly distributed colloidal magnetic nanoparticles in solution are polarized in the presence of an external magnetic field, and the interparticle dipole–dipole attraction drives their assembly into linear chains. In this Communication, we report using a model A3-coupling reaction, that the field-directed self-assembly of gold-coated magnetite (Fe3O4@Au) nanoparticles can be used to remotely control the rate of reaction by manipulating their colloidal assembly of catalyst in situ.

Gold nanorods are one of the most widely explored inorganic materials in nanomedicine for diagnostics, therapeutics and sensing 1 . It has been shown that gold nanorods are not cytotoxic and localize within cytoplasmic vesicles following endocytosis, with no nuclear localization 2,3 , but other studies have reported alterations in gene expression profiles in cells following exposure to gold nanorods, via unknown mechanisms 4 . In this work we describe a pathway that can contribute to this phenomenon. By mapping the intracellular chemical speciation process of gold nanorods, we show that the commonly used Au-thiol conjugation, which is important for maintaining the noble (inert) properties of gold nanostructures, is altered following endocytosis, resulting in the formation of Au(i)-thiolates that localize in the nucleus 5 . Furthermore, we show that nuclear localization of the gold species perturbs the dynamic microenvironment within the nucleus and triggers alteration of gene expression in human cells. We demonstrate this using quantitative visualization of ubiquitous DNA G-quadruplex structures, which are sensitive to ionic imbalances, as an indicator of the formation of structural alterations in genomic DNA.Traditionally, gold nanorods (GNRs) are synthesized with a non-covalently bound bilayer of cetyltrimethylammonium bromide (CTAB) that dissociates from the GNR surface under physiological conditions, resulting in significant cytotoxicity. This can be overcome by exchanging CTAB with a thiolated analogue-(16-mercaptohexadecyl)trimethylammonium bromide (MTAB)-to enable covalent interaction between the gold surface and pendant thiol groups resulting in highly efficient non-toxic cellular internalization 6 . In this study, we synthesized two distinct MTAB-modified GNRs of different lengths (54.1 ± 5.2 nm and 91.8 ± 11.3 nm) and identical diameters (19.0 ± 2.0 nm and 18.9 ± 2.4 nm) with corresponding aspect ratios (ARs) of 2.8 and 4.9, respectively ( Fig. 1b-d). We also synthesized MTAB-coated gold nanoparticles (GNPs, Fig. 1a) of similar diameter to the GNRs as a control to evaluate shapedependent contributions. The complete exchange of CTAB for its thiolated analogue MTAB was validated by the detection of sulfur using electron energy loss spectra (EELS) ( Supplementary Fig. 1). The zeta potentials of the GNPs/GNRs were 32.8 ± 0.6 (GNP), 36.8 ± 0.6 (AR 2.8) and 25.8 ± 1.2 (AR 4.9) ( Supplementary Fig. 2). The UV-vis absorbance of the GNRs demonstrated a characteristic redshift in the longitudinal surface plasmon resonance (LSPR) from 679 to 953 nm for the short (NRS) and long (NRL) nanorods, respectively (Fig. 1e). The presence of the sharp LSPR for the GNRs (full-width at half-maximum (FWHM) = 106.9 nm (AR 2.8) and 195.0 nm (AR 4.9)) is indicative of their narrow size distribution. Both GNR samples had negligible amounts of shape impurities (for example, spheres) (Fig. 1b,c).We next evaluated the toxicity profile and cellular internalization of the GNRs in HEK-293T and MCF-7 cells. The toxicity profiles included...