Photonic hydrogel sensors

Analyte-sensitive hydrogels that incorporate optical structures have emerged as sensing platforms for point-of-care diagnostics. The optical properties of the hydrogel sensors can be rationally designed and fabricated through self-assembly, microfabrication or laser writing. The advantages of photonic hydrogel sensors over conventional assay formats include label-free, quantitative, reusable, and continuous measurement capability that can be integrated with equipment-free text or image display. This Review explains the operation principles of photonic hydrogel sensors, presents syntheses of stimuli-responsive polymers, and provides an overview of qualitative and quantitative readout technologies. Applications in clinical samples are discussed, and potential future directions are identified

Polyyne Hybrid Compounds from Notopterygium incisum with Peroxisome Proliferator-Activated Receptor Gamma Agonistic Effects

[Image: see text] In the search for peroxisome proliferator-activated receptor gamma (PPARγ) active constituents from the roots and rhizomes of Notopterygium incisum, 11 new polyacetylene derivatives (1–11) were isolated. Their structures were elucidated by NMR and HRESIMS as new polyyne hybrid molecules of falcarindiol with sesquiterpenoid or phenylpropanoid moieties, named notoethers A–H (1–8) and notoincisols A–C (9–11), respectively. Notoincisol B (10) and notoincisol C (11) represent two new carbon skeletons. When tested for PPARγ activation in a luciferase reporter assay with HEK-293 cells, notoethers A–C (1–3), notoincisol A (9), and notoincisol B (10) showed promising agonistic activity (EC(50) values of 1.7 to 2.3 μM). In addition, notoincisol A (9) exhibited inhibitory activity on NO production of stimulated RAW 264.7 macrophages

Orientation of mesochannels in continuous mesoporous silica films by a high magnetic field

The effect of a high magnetic field on the orientation of mesochannels in continuous mesoporous silica films is demonstrated; the orientation of mesochannels in the film can be induced parallel to the magnetic field, though the effect is not complete

Photoresponsive glass-forming butadiene-based chiral liquid crystals with circularly polarized photoluminescence

The synthesis and study of the photo- and thermoresponsive behavior of a series of novel trimesogens consisting of a diphenylbutadiene core linked to cholesterol moieties on either side via flexible alkyl chains are reported. These molecules possess the combined glass-forming properties of bischolesterols and the photochromic and luminescent properties of the butadiene moiety. The pitch of the cholesteric phase of these materials could be continuously varied thermally and photochemically, making it possible to tune the color of the film over the entire visible region. The color images thus generated could be stabilized by converting them to N<SUP>&#8727;</SUP> glasses. These materials were also highly photoluminescent, exhibiting circularly polarized characteristics in the glassy liquid-crystalline state even by linearly polarized excitation

Indane-1,3-dione and cholesterol containing butadiene derivatives: photoresponsive liquid crystalline glasses for imaging applications

Synthesis, thermo-optical and glass forming properties of a series of photoresponsive luminescent mesogenic materials containing a butadiene moiety linked to a cholesterol group (CBIN, CBIN8 and CBIN12) as well as colour imaging devices based on them are described. These molecules exhibited relatively high fluorescence quantum efficiency in the solid and liquid crystalline states. The cholesteric phase was observed to be the major phase in these molecules and the pitch of cholesteric helix was sensitive to external stimuli such as temperature and light, making it possible to tune their iridescent colour in the visible region. The colour reflected by the cholesteric films could be stabilized by converting them to the glassy state by sudden cooling from their cholesteric phase to ~0 °C. Selective exposure of the material in its liquid crystalline phase to light resulted in trans-cis photoisomerization of the butadiene chromophore. Consequently the pitch of the irradiated portion changed depending upon the intensity of the illuminating light. The coloured images thus formed could be stored for long periods by converting the films to glasses by sudden cooling. The images stored in the glassy state were stable over long periods of time (>one year)