Melamine Foam-Derived Carbon Scaffold for Dendrite-Free and Stable Zinc Metal Anode.

Aqueous Zn-ion batteries (AZIBs) are one of the most promising large-scale energy storage devices due to the excellent characteristics of zinc metal anode, including high theoretical capacity, high safety and low cost. Nevertheless, the large-scale applications of AZIBs are mainly limited by uncontrollable Zn deposition and notorious Zn dendritic growth, resulting in low plating/stripping coulombic efficiency and unsatisfactory cyclic stability. To address these issues, herein, a carbon foam (CF) was fabricated via melamine-foam carbonization as a scaffold for a dendrite-free and stable Zn anode. Results showed that the abundant zincophilicity functional groups and conductive three-dimensional network of this carbon foam could effectively regulate Zn deposition and alleviate the Zn anode's volume expansion during cycling. Consequently, the symmetric cell with CF@Zn electrode exhibited lower voltage hysteresis (32.4 mV) and longer cycling performance (750 h) than the pure Zn symmetric cell at 1 mA cm-2 and 1 mAh cm-2. Furthermore, the full battery coupling CF@Zn anode with MnO2 cathode can exhibit a higher initial capacity and better cyclic performance than the one with the bare Zn anode. This work brings a new idea for the design of three-dimensional (3D) current collectors for stable zinc metal anode toward high-performance AZIBs.

The Detection of Food Additives Using a Fluorescence Indicator Based on 6- p-Toluidinylnaphthalence-2-sulfonate and Cationic Pillar[6]arene.

The current study investigated host-guest complexation in 6-p-toluidinylnaphthalene-2-sulfonate (TNS), a fluorescence probe used to investigate hydrophobic regions that contain the water-soluble cationic pillar[6]arene (CP6). After complexation with CP6, the fluorescence intensity of TNS was significantly increased. The decreases in the fluorescence intensity of the TNS•CP6 complex when phenolic food-additives are added have been used in indicator displacement assays to detect food additives in the water.

Carboxylato-Pillar[6]arene-Based Fluorescent Indicator Displacement Assays for Caffeine Sensing.

In the present work, we have developed a new indicator displacement system based on pillararene for anionic water-soluble carboxylato pillar [6] arene (WP6) and aromatic fluorescent dye safranine T (ST). A large fluorescence enhancement and colour change of ST were observed after complexation with electron-rich cavity in WP6 because of host-guest twisted intramolecular charge-transfer interactions. The constructed pillararene-indicator displacement system can be applied for caffeine selective detection in water.

Kinematics of Stewart Platform Explains Three-Dimensional Movement of Honeybee's Abdominal Structure.

The Stewart platform is a typical parallel mechanism, used extensively in flight simulators with six degrees of freedom. It is rarely found in animals and has never been reported to regulate and control physiological activities. Now an equivalent Stewart platform structure is found in the honey bee (Hymenoptera: Apidae: Apis mellifera L.) abdomen to explain its three-dimensional movements. The stereoscope and scanning electron microscope are used to observe the internal structures of honeybees' abdomens. Experimental observations show that the muscles and intersegmental membranes connect the terga with the sterna and guarantee the honey bee abdominal movements. From the perspective of mechanics, a Stewart platform is evolved from the lateral connection structure of the honey bee abdomen, and the intrasegmental muscles between the sternum and tergum function as actuators between planes of the Stewart platform. The extraordinary structure provides various advantages for a honey bee to complete a variety of physiological activities. This equivalent Stewart platform structure can also be used to illustrate the flexible abdominal movements of other insects with the segmental abdomen.

Acetylcholinesterase responsive polymeric supra-amphiphiles for controlled self-assembly and disassembly.

We have fabricated enzyme responsive polymeric supra-amphiphiles by mixing a block copolymer of poly(ethylene glycol)-block-poly(acrylic acid) with myristoylcholine chloride in water. The polymeric supra-amphiphiles self-assemble into spherical aggregates with sizes varying from about 40 to 150 nm. Moreover, the spherical aggregates can be disassembled triggered by acetylcholinesterase, an enzyme which can cut off the ester linkage of myristoylcholine chloride. Nile red can be loaded into the spherical aggregates and released in several hours upon the treatment of acetylcholinesterase. The releasing rate is rather fast considering that it takes more than 150 h for Nile red to diffuse out of the spherical aggregates without addition of acetylcholinesterase. It is anticipated that the new enzyme responsive polymeric supra-amphiphile may be explored as a carrier for drug delivery.

Host-guest chemistry at interface for photoswitchable bioelectrocatalysis.

Photoswitchable bioelectrocatalysis of glucose with glucose oxidase in an "On-Off" state is fabricated from host-guest chemistry at an interface by using the photocontrolled reversible immobilization and detachment of ferrocene-labeled redox-polymer as mediator.

Unconventional layer-by-layer assembly of graphene multilayer films for enzyme-based glucose and maltose biosensing.

We have developed an unconventional method for the layer-by-layer (LbL) assembly of graphene multilayer films. Unconventional LbL assembly was achieved by the following two-step process. Graphene sheets were modified by pyrene-grafted poly(acrylic acid) (PAA) in aqueous solution, and then the modified graphene sheets were used for layer-by-layer alternating deposition with poly(ethyleneimine) (PEI). The graphene-multilayer-film-modified electrode shows enhanced electron transfer for the redox reactions of Fe(CN)(6)(3-) and excellent electrocatalytic activity of H(2)O(2). On the basis of this property, a bienzyme biosensing system for the detection of maltose was fabricated by successive LbL assembly of graphene, glucose oxidase (GOx), and glucoamylase (GA). LbL assembly of graphene combines the excellent electrochemical properties of graphene and the versatility of LbL assembly, showing great promise in highly efficient sensors and advanced biosensing systems.

Combining host-guest systems with nonfouling material for the fabrication of a biosurface: toward nearly complete and reversible resistance of cytochrome c.

In this letter, a pH-responsive reactivated biointerface is fabricated using an inclusion reaction between an azobenzene-containing self-assembled monolayer and pH-responsive poly(ethylene glycol)-block-poly(acrylic acid) grafted with cyclodextrins. The pH-responsive interface can be switched between an extended state and a relaxed state for the reversible resistance of cytochrome c adsorption completely in cooperation with protein-resistant poly(ethylene glycol).