A fluorescently labeled dendronized polymer-enzyme conjugate carrying multiple copies of two different types of active enzymes

A hybrid structure of a synthetic dendronized polymer, two different types of enzymes (superoxide dismutase and horseradish peroxidase), and a fluorescent dye (fluorescein) was synthesized. Thereby, a single polymer chain carried multiple copies of the two enzymes and the fluorescein. The entire attachment chemistry is based on UV/vis-quantifiable bis-aryl hydrazone bond formation that allows direct quantification of bound molecules: 60 superoxide dismutase, 120 horseradish peroxidase, and 20 fluorescein molecules on an average polymer chain of 2000 repeating units. To obtain other enzyme ratios the experimental conditions were altered accordingly. Moreover, it could be shown that both enzymes remained fully active and catalyzed a two-step cascade reaction.

Nanometer-size anisotropy of injection-molded polymer micro-cantilever arrays

Understanding and controlling the structural anisotropies of injection-molded polymers is vital for designing products such as cantilever-based sensors. Such micro-cantilevers are considered as cost-effective alternatives to single-crystalline silicon-based sensors. In order to achieve similar sensing characteristics,structure and morphology have to be controlled by means of processing parameters including mold temperature and injection speed. Synchrotron radiation-based scanning small- (SAXS) and wide-angle x-ray scattering techniques were used to quantify crystallinity and anisotropy in polymer micro-cantilevers with micrometer resolution in real space. SAXS measurements confirmed the lamellar nature of the injection-molded semi-crystalline micro-cantilevers. The homogenous cantilever material exhibits a lamellar periodicity increasing with mold temperature but not with injection speed. We demonstrate that micro-cantilevers made of semi-crystalline polymers such as polyvinylidenefluoride, polyoxymethylene, and polypropylene show the expected strong degree of anisotropy along the injection direction.