Visual Detection of Thiocyanate Based on Fabry-Perot Etalons with a Responsive Polymer Brush as the Transducer.

The detection of thiocyanate (SCN-) is particularly important in industrial effluents and biological fluids because of the toxic nature of SCN-. Herein, a metal-insulator-metal (MIM) resonator for visual detection of SCN- is presented based on a poly[(2-(methacryloyloxy)ethyl) trimethylammonium chloride] (PMETAC) brush. The MIM resonator exhibits obvious color change as the concentration of SCN- changes, which can be easily distinguished by the naked eyes. In addition, the as-prepared MIM resonator also shows the advantages of good anti-interference, excellent reusability, and fast response rate. Combining the above advantages, the proposed MIM resonator may provide a broad perspective for a wide variety of visible-light applications.

Dynamic Tunable Color Display Based on Metal-Insulator-Metal Resonator with Polymer Brush Insulator Layer as Signal Transducer.

Dynamic color-changing nanomaterials have been widely investigated for applications in fields like optical sensors, wearable activity monitors, smart electronic devices, and anticounterfeiting materials due to the excellent ability to change their optical properties with external variation. Here, a simple metal-insulator-metal (MIM) trilayer Fabry-Perot resonance cavity with a poly(N-isopropylacrylamide) (PNIPAm) brush layer as a responsive element is reported as a thermal-induced colorimetric response platform. The dynamic changes of conformation and physical properties of PNIPAm brush layer in response to external signals give rise to a significant color change of the MIM Fabry-Perot resonance cavity. This MIM Fabry-Perot resonance cavity shows the advantages of dynamic color change, rapid response, good repeatability, and simple construction. Additionally, the as-prepared MIM cavity shows great potential in various applications such as color printing, multicolor indicator, and information anticounterfeiting.