Vanadium oxide/poly (3,4‐ ethylenedioxythiophene)(V2O5‐PEDOT) hybrid materials were prepared in a rotating quartz plasma reactor via capacitively coupled radio frequency (RF 13.56 MHz) plasma. Thin films of V2O5‐PEDOT hybrid and V2O5 were obtained by electron beam evaporation technique onto flexible PET substrate for electrochromic devices (ECDs) applications. As a counter electrode, both RF magnetron sputtered MoO3 onto ITO coated PET and only ITO coated PET electrodes were used. Characterizations of the films were carried out via using scanning electron microscopy‐energy dispersive X‐ray spectroscopy (SEM‐EDX) and X‐ray diffraction (XRD). Hybrid ECDs results showed that synergistic effect depending on improved stability between V2O5 and PEDOT. As a result, we developed all solid complementary electrochromic devices including V2O5, V2O5‐PEDOT and MoO3 films. The electrochromic device characteristics such as electrochromic contrast, coloration efficiency, switching time were calculated from optical and electrochemical measurements. The highest coloration efficiency and optical contrast were obtained as 53 cm2/C and 17 % for V2O5‐PEDOT/MoO3‐based ECD.

Future biomedical applications of nanomachines require elimination of fuel requirements since most of the fuels have potential toxic effects. Herein, we report fuel-free magnetically powered gold–nickel (Au–Ni) nanowires as nanomotors for multipurpose biomedical applications. Fabrication of the nanowire-based nanomotors developed in this study is unique, and this protocol was dependent on the electrochemical preparation of Au nanowires followed by the direct current (DC) magnetron sputtering of Ni part. DC magnetron sputtering-based preparation used for the first time in the literature not only ensured homogeneous distribution and rapid deposition of the metal directly but also provided reproducible thin layers of magnetic Ni resulting in a significant improvement at nanomotor speeds. Besides magnetic propulsion, acoustic propulsion was also successfully applied. The effects of both propusion mechanisms were tested on the speed and direction of Au–Ni nanomotors. Biomedical applications of the motors accomplished in this study are rapid and sensitive detection of an important cancer biomarker microRNA-21 (miRNA-21) and pH-dependent and near-infrared (NIR) triggered release of a commonly used chemotherapeutic drug doxorubicin (DOX). Sensitive and selective miRNA-21 detection was achieved by using dye-labeled single-stranded DNA (ssDNA probe) modified Au–Ni nanomotors with a wide linear concentration range of 0.01 nM to 25 nM. Low detection limits of 2.9 pM and 1.6 pM were obtained for fluorescence and speed-based detection, respectively (n = 3). In addition, magnetically powered DOX-loaded Au–Ni nanomotors were guided on cancer cells (human breast cancer cell lines, MCF-7) in a controllable way for the efficient and controlled delivery of DOX. Cytotoxicity studies of the nanomotors presented negligible influence on the cell viability.

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This study focuses on the electrochromic device (ECD) applications of poly(3,4‐ethylenedioxythiophene)/tungsten oxide (PEDOT/WO3) hybrid nanofibers prepared via electrospinning method. Nanoporous WO3 films were initially electrosynthesized on Pt sheet. The PEDOT layer was electropolymerized onto the entire surface of the WO3 nanoporous host framework in the presence of different ionic liquids: 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BMIMBF4), 1‐butyl‐3‐methylimidazolium hexafluorophosphate (BMIMPF6), 1‐butyl‐ 3‐methylimidazolium bis(trifluoromethylsulfonyl) imide (BMIMTFSI), and 1‐butyl‐1‐methylpyrrolidinium bis(trifluoromethylsulfonyl) imide (BMPTFSI). The morphological features and elemental surface characterization of hybride nanofibers were monitored by scanning electron microscopy and energy dispersive X‐ray spectroscopy. ECDs changed color reversibly from transparent to light brown by switching from +3 V to −3 V. It was found that the highest optical modulation of 47.89 % and maximum coloration efficiency of 363.72 cm2/C is achieved for PEDOT/WO3/BMIMPF6 based electrochromic device. Hybrid nanofibers exhibited excellent long term stability even after 1000 chronoamperometric cycles. This work could not only push forward the facile preparation of PEDOT/WO3 nanofibers but also represent, for the first time, the possibility that the hybrid nanofibers could be a promising material for the highly efficient ECDs.

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