Fluorescent Holographic Fringes with a Surface Relief Structure Based on Merocyanine Aggregation Driven by Blue-violet Laser

Preparation and properties of a polyurethane film based on novel photochromic spirooxazine chain extension

A smart polyurethane material with good photoresponsiveness and reversible surface wettability based on a photoresponsive chain extender (SO–OH).

Plasmon-driven light harvesting in poly(vinyl alcohol) films for precise surface topography modulation

Efficient light harvesting is essential for advanced photonic devices. Complex micro/nano surface relief structures can be produced via light-triggered mechanical movement, but limited in organic active molecular units. In this Letter, we propose to embed noble-metal particles into light-inactive polyvinyl alcohol matrix to construct a light harvesting system driven by plasmon for inscription of surface relief gratings. Ultra-small-sized silver nuclei are generated in the polymer by pre-thermal treatment, acting as an accelerator for the subsequent photoinduced particle growth, hydrogen group cleavage, and matrix softening. Based on such properties, a complex plasmonic array carrying ultra-high-density information is achieved with peristrophic multiplexing holography. This Letter paves a bright way to realize data storage, information encryption, and optical microcavity.

Improved photothermal therapy of brain cancer cells and photogeneration of reactive oxygen species by biotin conjugated gold photoactive nanoparticles

Herein, we report on the design and development of functionalized acrylic polymeric nanoparticles with Spiropyrans (SPs) and imidazole moieties via superficial polymerizations. Then, Au³⁺ ions were immobilized and reduced on their surface to obtain photoresponsive gold-decorated polymer nanoparticles(Au-NPs). The synthesized Au-NPs were surface adapted with biotin as specific targeting tumor penetration cells and enhance the intercellular uptake through the endocytosis. FT-IR (Fourier-transform Infrared Spectroscopy), UV-Vis (Ultra Violet-Visible Spectrophotometer), EDS (Energy Dispersive X-Ray Spectroscopy), SEM (Scanning Electron Microscope) and HR-TEM (High-resolution transmission electron microscopy) descriptions were engaged to illustrate their spectral analysis and morphological examinations of Bt@Au-NPs. Fluorescence microscopy images of cellular uptake descriptions and ICP-MS (Inductively coupled plasma mass spectrometry) investigation established the cell lines labeling ability and enhanced targetting efficacy of biotin-conjugated Au-NPs (Bt@Au-NPs) toward C6 glioma cells (brain cancer cells) with 72.5% cellular uptake relative to 30.2% for non-conjugated lone. These were further established through intracellular ROS examinations and in vitro cytotoxicity investigation on the C6 glioma cell line. The solid surface plasmon absorptions of the Au-NPs and Bt@Au-NPs providing raised photothermal therapy under UV irradiation. The synthesized multifunctional Bt@Au-NPs with an inclusive combination of potential resources presented encouraging nanoprobe with targeting capability, improved photodynamic and photothermal cancer therapy.

Design of Collective Motions from Synthetic Molecular Switches, Rotors, and Motors

Precise control over molecular movement is of fundamental and practical importance in physics, biology, and chemistry. At nanoscale, the peculiar functioning principles and the synthesis of individual molecular actuators and machines has been the subject of intense investigations and debates over the past 60 years. In this review, we focus on the design of collective motions that are achieved by integrating, in space and time, several or many of these individual mechanical units together. In particular, we provide an in-depth look at the intermolecular couplings used to physically connect a number of artificial mechanically active molecular units such as photochromic molecular switches, nanomachines based on mechanical bonds, molecular rotors, and light-powered rotary motors. We highlight the various functioning principles that can lead to their collective motion at various length scales. We also emphasize how their synchronized, or desynchronized, mechanical behavior can lead to emerging functional properties and to their implementation into new active devices and materials.

Merocyanines based on 1,2-diphenyl-3,5-pyrazolidinedione

The acceptor strength of the 1,2-diphenyl-3,5-pyrazolidinedione residue is re-evaluated based on the spectral-fluorescent properties of donor–acceptor dyes. Low fluorescence of the title compounds is explained by the low-lying forbidden ππ*-state.