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Tubular polyaniline (PANI)/Zn micro-rockets are described that display effective autonomous motion in extreme acidic environments, without any additional chemical fuel. These acid-driven hydrogen-bubble-propelled microrockets have been electrosynthesized using the conical polycarbonate template. The effective propulsion in acidic media reflects the continuous thrust of hydrogen bubbles generated by the spontaneous redox reaction occurring at the inner Zn surface. The propulsion characteristics of PANI/Zn microrockets in different acids and in human serum are described. The observed speed-pH dependence holds promise for sensitive pH measurements in extreme acidic environments. The new microrockets display an ultrafast propulsion (as high as 100 body lengths/s) along with attractive capabilities including guided movement and directed cargo transport. Such acid-driven microtubular rockets offer considerable potential for diverse biomedical and industrial applications. [ABSTRACT FROM AUTHOR]

The first aryldiimine NCN-pincer ligated rare earth metal dichiorides (2,6-(2,6-C6H3R2N=CH)2-C6H3)LnCl2(THF)2 (Ln = Y, R = Me (1), Et (2), iPr (3); R = Et, Ln = La (4), Nd (5), Gd (6), Sm (7), Eu (8), Tb (9), Dy (10), Ho (11), Yb (12), Lu (13)) were successfully synthesized via transmetalation between 2,6-(2,6-C6H3-R2N=CH)2-C6H3Li and LnCl3(THF)1~3.5. These complexes are isostructural monomers with two coordinating THF molecules, where the pincer ligand coordinates to the central metal ion in a κC:κN:κN′ tridentate mode, adopting a meridional geometry. Complexes 1-6, 9-11, and 13 combined with aluminum tris(alkyl)s and [Ph3C][B(C6F5)4] established a homogeneous Ziegler-Natta catalyst system, which exhibited high activities and excellent cis-1,4 selectivities for the polymerizations of butadiene (Tp = 25 °C, 99.9%; 0 °C, 100%) and isoprene (T~ = 25 °C, 98.8%). Remarkably, such high cis-1,4 selectivity almost remained at elevated polymerization temperatures up to 80 °C and did not vary with the type of the central lanthanide element, however, which was influenced obviously by the ortho substituent of the N-aryl ring of the ligands and the bulkiness of the aluminum alkyls. The Ln-Al bimetallic cations were considered as the active species. These results shed new light on improving the catalytic performance of the conventional Ziegler-Natta catalysts for the specific selective polymerization of dienes. [ABSTRACT FROM AUTHOR]

Intracellular H2O2 plays an important role in regulating a variety of cellular functions. Fluorescent probes that can make response to intracellular levels of H2O2 would provide valuable tools for revealing the functions of H2O2 in living organisms. However, traditional pH-in sensitive probes and lysosome-targetable probes can only provide spatially nonspecific visualization of intracellular H2O2 and specific sensing of lysosomal H2O2, respectively. In this work, we developed a H2O2-responsive and pH-switchable fluorescent probe (HP-Ll) which can make response sequentially to intracellular H2O2 and lysosomal pH. The fluorescent probe is comprised of a H2O2- responsive boronate moiety and a pH-switchable spirobenzopyran fluorophore. When the probe was applied for intracellular H2O2 sensing, only fluorescent emission from lysosomes is visible, and the fluorescence from other regions is not able to be obviously detected, which is due to the pH-switchable property of the spirobenzopyran fluorophore. Thus, the developed fluorescence probe enables the spatially confined (Le., lysosome-spedfic) visualization of the intracellular H2O2. We envisioned that this kind of fluorescent probe (or the proposed sensing strategy) would allow the visualization of the overall levels of intracellular H202 without interferences of possible fluorescent signals from other sources (e.g., dyes for cellular staining and multiplex analysis). [ABSTRACT FROM AUTHOR]

New template-based self-propelled gold/nickel/polyaniline/platinum(Au/Ni/PANI/Pt) microtubular engines, functionalized with the ConcanavalinA (ConA) lectin bioreceptor, are shown to be extremely useful forthe rapid, real-time isolation of Escherichia coli(E. coli) bacteria from fuel-enhanced environmental,food, and clinical samples. These multifunctional microtube enginescombine the selective capture of E. coliwith theuptake of polymeric drug-carrier particles to provide an attractivemotion-based theranostics strategy. Triggered release of the capturedbacteria is demonstrated by movement through a low-pH glycine-baseddissociation solution. The smaller size of the new polymer-metal microenginesoffers convenient, direct, and label-free optical visualization ofthe captured bacteria and discrimination against nontarget cells. [ABSTRACT FROM AUTHOR]