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Photosynthetic inorganic biohybrid systems (PBSs) combining an inorganic photosensitizer with intact living cells provide an innovative view for solar hydrogen production. However, typical whole-cell biohybrid systems often suffer from sluggish electron transfer kinetics during transmembrane diffusion, which severely limits the efficiency of solar hydrogen production. Here, a unique biohybrid system with a quantum yield of 8.42% was constructed by feeding bismuth-doped carbon dots (Bi@CDS) to Escherichia coli(E. coli). In this biohybrid system, Bi@CDScan enter the cells and transfer the electrons upon light irradiation, greatly reducing the energy loss and shortening the distance of electron transfer. More importantly, the photocatalytic hydrogen production of the E. coli–Bi@CDs biohybrid system reached up to 0.95 mmol within 3 h under light irradiation (420–780 nm, 2000 W m–2), which is 1.36 and 2.38 times higher than that in the E. coli–CDs biohybrid system and the E. colisystem, respectively. In addition, the mechanism of enhanced hydrogen production was further explored. It was found that the accelerated decomposition of glucose, the accelerated production of pyruvate, the inhibition of lactic acid, and the increase of formic acid were the reasons for the increase of hydrogen production. This work provides a novel strategy for improving the hydrogen production in photosynthetic inorganic biohybrid systems.

Natural killer (NK) cell-based adoptive immunotherapy has demonstrated encouraging therapeutic effects in clinical trials for hematological cancers. However, the effectiveness of treatment for solid tumors remains a challenge due to insufficient recruitment and infiltration of NK cells into tumor tissues. Herein, a programmed nanoremodeler (DAS@P/H/pp) is designed to remodel dense physical stromal barriers and for dysregulation of the chemokine of the tumor environment to enhance the recruitment and infiltration of NK cells in tumors. The DAS@P/H/pp is triggered by the acidic tumor environment, resulting in charge reversal and subsequent hyaluronidase (HAase) release. HAase effectively degrades the extracellular matrix, promoting the delivery of immunoregulatory molecules and chemotherapy drugs into deep tumor tissues. In mouse models of pancreatic cancer, this nanomediated strategy for the programmed remodeling of the tumor microenvironment significantly boosts the recruitment of NK92 cells and their tumor cell-killing capabilities under the supervision of multiplexed near-infrared-II fluorescence.

Selective labeling of the protein of interest (POI) in genetically unmodified live cells is crucial for understanding protein functions and kinetics in their natural habitat. In particular, spatiotemporally controlled installation of the labels on a POI under light control without affecting their original activity is in high demand but is a tremendous challenge. Here, we describe a novel ligand-directed photoclick strategy for spatiotemporally controlled labeling of endogenous proteins in live cells. It was realized with a designer labeling reagent skillfully integrating the photochemistries of 2-nitrophenylpropyloxycarbonyl and 3-hydroxymethyl-2-naphthol with an affinity ligand. Highly electrophilic ortho-naphthoquinone methide was photochemically released and underwent a proximity coupling reaction with nucleophilic amino acid residues on the POI in live cells. With fluorescein as a marker, this photoclick strategy enables time-resolved labeling of carbonic anhydrase subtypes localized either on the cell membrane or in the cytoplasm and a discriminable visualization of their metabolic kinetics. Given the versatility underlined by facilely tethering other functional entities (e.g., biotin, a peptide short chain) via acylation or (in cell) Huisgen cycloaddition, this affinity-driven photoclick chemistry opens up enormous opportunities for discovering dynamic functions and mechanistic interrogation of endogenous proteins in live cells.

Increasing resistance to carbapenem antibiotics has become a particular concern. Combination therapy might constitute an effective way to control drug-resistant bacterial infections. Here, we show that AuRh nanoparticles (NPs) have a synergistic antibacterial effect with a small-molecule antibiotic (imipenem), and they exhibit excellent antibacterial efficacies by increasing intracellular reactive oxygen species levels and enhancing the permeability of the bacterial membrane. In particular, the combination therapy restores the efficacy of imipenem against carbapenem-resistant Klebsiella pneumoniae(CRKP), with a 128-fold reduction in the minimum inhibitory concentration. In the treatment of lung infections, the combination of AuRh NPs (2 mg kg−1) and imipenem (2 mg kg−1) more effectively inhibits CRKP infection, with a 50% increase in the survival rate of mice compared with groups treated with imipenem or AuRh NPs alone. For in vitroand in vivosafety studies, AuRh NPs combined with imipenem show no significant toxicity, even at an injected concentration of 100 mg kg−1in mice. This combination therapeutic provides an effective treatment for drug-resistant bacterial infections.

In electrocatalytic conversion of earth-abundant small molecules (e.g., H2O, O2, CO2, N2), thorough understanding of the interface chemistry under the operating conditions is the cornerstone of design and construction of high-performance catalytic systems (electrolytes and electrodes). Frequently, limited comprehension of characterization tools leads to bewilderment in the system selection and/or experimental design. This perspective discusses the advance, limitation, and outlook of the state-of-the-art operandotechniques involving investigation of electrocatalytic interfaces, including IR, Raman, UV-vis, XAFS, Mössbauer spectroscopy, AP-XPS, AFM, and SECCM. This perspective aims to help researchers in aspects of system selection, experimental design, and mechanism study in electrocatalysis.

Electrochemical water splitting into hydrogen is a promising strategy for hydrogen production powered by solar energy. However, the cell voltage of an electrolyzer is still too high for practical application, which is mainly limited by the sluggish oxygen evolution reaction process. To this end, hybrid water electrolyzers have drawn tremendous attention. Herein, coaxial Ni/Ni3S2@N-doped nanofibers are directly grown on nickel foam (NF), which is highly active for hydrogen evolution reaction. Meanwhile, the Ni3S2@N-doped nanofibers on NF prepared in an Ar atmosphere display superior urea oxidation reaction performance to previously reported catalysts. The cell voltage is about 1.50 V in urea electrolysis to deliver a current density of 20 mA cm–2, lower than that of a traditional water electrolyzer (1.82 V). The current density is around 77% relative to its initial value of 20 mA cm–2after 20 h, superior to Pt/C|Ir/C-based urea electrolysis (14%). It is found that the synergistic effect between metallic Ni and Ni3S2, as well as the interfacial effect between metal centers and N-doped carbon, favors the initial dissociation of H2O and the adsorption/desorption of H* with thermal neutral Gibbs free energy. Meanwhile, the in-situ generated NiOOH on the outer surface of Ni3S2possessed lower electrochemical activation energy for urea decomposition. Meanwhile, the abundant oxygen vacancies in electrodes could expose more active sites for the adsorption of intermediates, including H* and OOH*. It is also found that the hierarchical nanostructure of densely packed nanowires provides ideal electronic and ionic transport paths for fast electrocatalytic kinetics. The present work indicated that the modulation of compositions and hierarchical nanostructure is effective to prepare efficient catalysts for H2production viaurea electrolysis.

Oral administration is a facile and safe way for medication. However, most of the reported nanomedicines could not be taken orally, partially due to their unsatisfied stability, poor absorbance, or toxicity in the gastrointestinal tract. Here, we demonstrate that we could robustly synthesize gold nanoparticles (GNPs) in vivoby orally administering two starting materials, tetrachloroauric acid and aminophenyl boronic acid (ABA). The ABA-activated GNPs (A-GNPs) synthesized in vivocould be absorbed by the gastrointestinal tract and reach the remote infection lesions such as peritonitis caused by multidrug resistant (MDR) bacteria in mice. The A-GNPs exhibit excellent antibacterial efficacy (MIC, 3 μg/mL), long half-life (16–17 h), effective clearance (residual concentration is near 0 within 72 h), and high biosafety (safe dose/effective dose, 8 times). Our study is a pioneering attempt for synthesizing and taking nanomedicines orally just like preparing and drinking a cocktail.

Multidrug-resistant (MDR) bacteria-induced infections are becoming challenging issues threatening human health and life. Current antibiotics can hardly tackle this problem. Herein, we present a strategy to prepare mercaptophenylboronic acid (MBA)-activated gold nanoparticles (Au NPs) as an antibacterial agent against MDR bacteria. Both Au NPs and MBA cannot serve as antibiotics. However, when MBA attaches on Au NPs, the Au_MBA NPs show potent antibacterial activities against Gram-positive MDR clinical isolates (e.g., MDR Staphyloccocus aureus, MDR S. aureus; MDR Staphyloccocus epidermidis, MDR S. epidermidis). Furthermore, Au_MBA NPs show an extremely high median lethal dose (LD50,i.v.,960 mg/kg), which is much higher than those of most of the clinically used antibiotics. As an application example, we dope Au_MBA NPs with electrospun poly(ε-caprolactone) (PCL)/gelatin nanofibrous membranes as wound dressings, which show striking ability to remedy S. aureus- or MDR S. aureus-infected full-thickness skin wounds on rats. Our study provides a novel strategy for treating MDR bacteria-infected wounds in a simple, low-cost, and efficient way, which holds promise for broad clinical applications.

With the widespread use of antibiotics, the number of complex infection cases caused by unknown pathogens is increasing and novel antibiotics with tunable antibacterial spectra and low toxicity are highly desirable. Herein, we report that, by selecting thiol or amine, two groups with different binding affinities with gold, as anchoring groups, phenylboronic acid can be decorated on gold nanoparticles (AuNPs) with different densities, which contributes to Gram-selective antibacterial activities of the AuNPs. The AuNPs modified with amine- or thiol-tethered phenylboronic acids specifically bind to lipopolysaccharide (LPS, Gram-negative) or lipoteichoic acid (LTA, Gram-positive), respectively. By modifying AuNPs with different ratios of thiol- and amine-tethered phenylboronic acids, the resulting AuNPs show potent and tunable antibacterial activity. The AuNP-based antibacterial agents with optional Gram selectivity are promising for applications in personalized therapy.

There is a growing demand for antibacterial materials around the world in recent years because they can be used for preventing pathogen infection, which is one of the major threats to human health. However, the mechanical damage of the antibacterial materials may weaken their protective effect since bacteria can invade through the cracks of the material. Therefore, antibacterial materials with self-healing ability, in which the mechanical damage can be spontaneously healed, exhibit better reliability and a longer lifespan. In this article, we prepared a series of low-cost antibacterial polymer blends and polymer/small molecule blend materials with excellent self-healing ability and high mechanical strength by a one-pot reaction under mild conditions. These materials were facilely obtained by blending a tiny amount of commercialized cationic antibacterial chemicals, poly(ethylene imine) (PEI) or cetyltrimethylammonium bromide (CTAB), into a self-healing, mechanically robust polymer, poly(ether-thioureas) (PETU). It can be found that they can effectively kill Escherichia coli(Gram-negative) and Staphylococcus aureus(Gram-positive) on their surface. Meanwhile, the distinguished advantages of PETU, including self-healing property, excellent mechanical robustness, recyclability, and transparency, were perfectively maintained. Furthermore, it was shown that their cytotoxicity was satisfactory and their hemolytic activity was insignificant. The above advantages of the blend materials suggested their potential applications in health care, food industry, and environmental hygiene.

Highly efficient recognition of cancer cells by immune cells is important for successful therapeutic-cell-based cancer immunotherapy. Herein, we present a facile NIR-II nanoadaptor [hyaluronic acid (HA)/dibenzocyclooctyne (DBCO)-Au:Ag2Te quantum dots (QDs)] for enhancing the tumor recognition and binding ability of natural killer (NK) cells via a bio-orthogonal click reaction in vivo. The Nanoadaptor possesses superior tumor-targeting capacity, facilitating the accumulation of the chemical receptor DBCO at the tumor sites. Subsequently, the enrichment of DBCO on tumor cell surfaces provides multivalent recognition sites for capturing pretreated azide engineered NK92 cells (NK92-N3) through an efficient click reaction, thereby significantly enhancing the therapeutical efficiency. The dynamic process of nanoadaptor-mediated recognition of NK cells to tumor cells could be vividly observed using multiplexed NIR-II fluorescence imaging in a mouse model of lung cancer. Such a nanoadaptor strategy can be extended to other therapeutic cellular systems and holds promise for future clinical applications.

Soft robots have great potential applications in manufacturing, disaster rescue, medical treatment, etc. Artificial muscle is one of the most important components of a soft robot. In previous years, hydrogel actuators that can be controllably deformed by the stimuli of external signals have been developed as good candidates for muscle-like materials. In this article, we successfully prepared a chemical fuel-driven self-resettable bilayer hydrogel actuator mimicking natural muscles with the aid of a new negative feedback reaction network. The actuator can temporarily deform upon the addition of H+(chemical fuel). Subsequently, H+accelerated the reaction between BrO3–and Fe(CN)64–, which consume H+. It resulted in the spontaneous recovery of the pH as well as the shape of the actuator. Such an actuator exhibits a great similarity with natural muscles in actuation mechanisms and automaticity in the manipulation compared to the widely reported stimuli-responsive hydrogel actuators. This illustrates that fuel-driven self-resettable hydrogel is a promising dynamic material for mimicking the functions of living creatures.

In this study, a yeast@ZIF-8 core–shell composite material was successfully synthesized under room temperature in aqueous solution. The ZIF-8 shell endowed the inner yeast cells with a considerably extended lifetime without any nutrients at 4°C. Compared with the bare yeast cells, most coated yeast cells were kept alive even when cultured in zymolyase solution for 3 h. Furthermore, the encapsulated yeast cells could be reactivated and regrown by dissolving the ZIF-8 shell with competitive coordination interactions. 在本文中, 沸石型金属有机框架材料ZIF-8在温和的条件下被成功包覆于活细胞酿酒酵母表面. ZIF-8壳层展示出对酿酒酵母细胞明显的保护作用. 与裸露酵母相比, 包覆酵母在4°C纯水中可以保持更长时间的代谢活性. 当包覆酵母和裸露酵母在酵母裂解酶存在的溶液中共同培养时, 包覆酵母仍然保持约80%的活性, 而裸露酵母则几乎全部死亡. 除此之外, 用EDTA将ZIF-8壳层溶解之后, 包覆的酵母仍然具有再生增殖能力, 且其生长曲线与裸露酵母类似.

Dissipative self-assembly is an intriguing but challenging research topic in chemistry, materials science, physics, and biology because most functional self-assembly in nature, such as the organization and operation of cells, is actually an out-of-equilibrium system driven by energy dissipation. In this article, we successfully fabricated an I2-responsive supra-amphiphile by a PEGylated poly(amino acid) and realize its dissipative self-assembly in batch reactor by coupling it with the redox reaction between NaIO3and thiourea, in which I2is an intermediate product. The formation and dissipative self-assembly of the supra-amphiphile can be repeatedly initiated by adding the mixture of NaIO3and thiourea, which herein acts as “chemical fuel”, while the lifetime of the transient nanostructures formed by the dissipative self-assembly is easily tuned by altering thiourea concentration in the “chemical fuel”. Furthermore, as an application demo, the dissipative self-assembly of the supra-amphiphile is examined to control dispersion of multiwalled carbon nanotubes in water, exhibiting a good performance of organic pollutant removal.

Over the past years the performance of electrochromic smart windows with the promising potential for significant energy savings has been progressively improved; however, the electrochromic windows have not yet to come into use at scale mainly because the electrochromic materials suffer from some significant drawbacks such as low coloration efficiency, slow switching time, bad durability and poor functionality. Herein, we fabricate the optically modulated electrochromic smart devices through sequential deposition of the crown-type polyoxometalates, K28Li5H7P8W48O184·92H2O (P8W48), and W18O49nanowires. Unlike most reported electrochromic smart devices, the resulting P8W48and W18O49nanocomposites allow active and selective manipulation of the transmittance of near-infrared (750–1360 nm) and visible light (400–750 nm) by varying the applied potential. Furthermore, thanks to the stable nature of both P8W48and W18O49and precise structural control over the nanocomposites, the prepared electrochromic smart devices exhibit high efficiency, quick response and excellent stability.

Microbial fuel cells (MFCs) have been shown as a promising technology for sustainable energy production and wastewater treatment. However, the still relatively insignificant power generation and high costs of MFCs limit its large-scale application. Herein, we report a facile and low-cost route to construct nitrogen-doped 3D macroporous carbon (NPVP-RFC) via pyrolysis of self-assembled structure of cross-linked resorcinol–formaldehyde resin (RF), polyvinyl pyrrolidone (PVP) and dicyandiamide (DCDA). The as-prepared NPVP-RFC material provides a large specific surface area for high-density loading of bacteria. Moreover, the incorporation of active N species into carbon frameworks offers a hydrophilic surface with good electrolyte wettability and increased conductivity for promoting biofilm adhesion and enhancing extracellular electron transfer (EET) process, thus enabling a high-power output. Thus, the NPVP-RFC MFCs achieve fast start-up time of 2.9 days and maximum volumetric power density of 9.23 W/m3at 21.48 A/m3. Notably, the NPVP-RFC MFCs show good and stable performance for beer brewery wastewater treatment, achieving a maximum volumetric power density of 6.38 W/m3, chemical oxygen demand (COD) removal efficiency of 84.83%, and a columbic efficiency of 35.57%. This work provides a facile and low-cost synthesis technique for fabricating high-performance MFC anodes for use in microbial energy harvesting.

The oxygen reduction reaction (ORR) is one of the key steps in clean and efficient energy conversion techniques such as in fuel cells and metal–air batteries; however, several disadvantages of current ORRs including the kinetically sluggish process and expensive catalysts hinder mass production of these devices. Herein, we develop carbonized nanoparticles, which are derived from monodisperse nanoscale metal organic frameworks (MIL-88B-NH3), as the high performance ORR catalysts. The onset potential and the half-wave potential for the ORR at these carbonized nanoparticles is up to 1.03 and 0.92 V (vsRHE) in 0.1 M KOH solution, respectively, which represents the best ORR activity of all the non-noble metal catalysts reported so far. Furthermore, when used as the cathode of the alkaline direct fuel cell, the power density obtained with the carbonized nanoparticles reaches 22.7 mW/cm2, 1.7 times higher than the commercial Pt/C catalysts.

Vertically aligned CdTe–ZnO composite nanorods are constructed on the indium tin oxide substrates by layer-by-layer deposition of CdTe quantum dots on ZnO nanorod arrays. The CdTe shell forms an intact interface with the wurtzite ZnO nanorod, and its thickness can be accurately tuned by changing the deposition cycles. Photoluminescent measurements further disclose the band alignment between the CdTe shell and the ZnO core, which makes CdTe–ZnO composite nanorods exhibiting good photoelectron-chemical properties and being a prospective material for removal of phenol from wastewater under visible light irradiation. Impressively, about 75% degradation of 100 mg/L phenol solution and up to 53.2% removal of the total organic carbon are achieved within 150 min using the optimized CdTe–ZnO composite nanorods as photoelectrocatalysts under visible light.

Copper chalcogenide nanoparticles (NPs) represent a promising material for solar energy conversion, electrical charge storage, and plasmonic devices. However, it is difficult to achieve high-quality NP dispersions in experimentally convenient and technologically preferred aqueous media. Also problematic is the transition from NP dispersion to continuously crystalline nanoscale materials, for instance, nanowires, nanoribbons, or similar high aspect ratio nano/microstructures capable of charge transport necessary for such applications. All previous examples of copper sulfide assemblies contained insulating gaps between NPs. Here we show that aqueous synthesis of high-quality monodispersed high-chalcocite β-Cu2S NPs, with sizes from 2 to 10 nm, is possible. When reaction time increased, the NP shape evolved from nearly spherical particles into disks with predominantly hexagonal shape. Moreover, the monodispersed β-Cu2S NPs were found to spontaneously self-assemble into nanochains and, subsequently, to nanoribbons. The width and length of the nanoribbons were 4–20 nm and 50–950 nm, respectively, depending on the assembly conditions. We observed the formation of the nanoribbons with continuous crystal lattice and charge transport pathways, making possible the utilization of self-assembly processes in the manufacturing of photovoltaic, plasmonic, and charge storage devices.

Image-guided phototherapy is considered to be a prospective technique for cancer treatment because it can provide both oncotherapy and bioimaging, thus achieving an optimized therapeutic efficacy and higher treatment accuracy. Compared to complicated systems with multiple components, using a single material for this multifunctional purpose is preferable. In this work, we strategically fabricated poly(acrylic acid)- (PAA-) coated Cu2(OH)PO4quantum dots [denoted as Cu2(OH)PO4@PAA QDs], which exhibit a strong near-infrared photoabsorption ability. As a result, an excellent photothermal conversion ability and the photoactivated formation of reactive oxygen species could be realized upon NIR irradiation, concurrently meeting the basic requirements for photothermal and photodynamic therapies. Moreover, phototherapeutic investigations on both cervical cancer cells in vitro and solid tumors of an in vivo mice model illustrated the effective antitumor effects of Cu2(OH)PO4@PAA upon 1064-nm laser irradiation, with no detectable lesions in major organs during treatment. Meanwhile, Cu2(OH)PO4@PAA is also an exogenous contrast for photoacoustic tomography (PAT) imaging to depict tumors under NIR irradiation. In brief, the Cu2(OH)PO4@PAA QDs prepared in this work are expected to serve as a multifunctional theranostic platform.

A variety of functional nanostructured organic/inorganic hybrid materials from the europium‐exchanged derivative of a Preyssler‐type polyoxometalate (POM), [EuP5W30O110]12−, and functional organic surfactants were prepared by the ionic self‐assembly (ISA) route. The effect of organic surfactants on the structure, photoluminescent, electrochemical and electrochromic properties of the POM anions was investigated in detail. All obtained hybrid materials are amphotropic, i.e., exhibit both thermotropic and lyotropic liquid‐crystalline phase behaviour. Investigations of their photophysical properties have shown that the interactions of the various surfactants with the polyanions influence the coordination environments and site symmetry of Eu3+in different ways. The functional groups in the organic surfactants significantly influence the electrochromic properties and photoluminescence of POMs. Different from normal and pyridine‐containing complexes, no photoluminescence and no electrochromism were observed from the ferrocene‐containing complexes. This may be explained in view of charge transfer between the POM anion and the ferrocenyl group.

Microbial fuel cells (MFCs) are promising ecofriendly techniques for harvesting bioenergy from organic and inorganic matter. Currently, it is challenging to design MFC anodes with favorable microorganism attachment and fast extracellular electron transfer (EET) rate for high MFC performance. Here we prepared N-doped carbon nanotubes (NCNTs) on carbon felt (CF) and used it as a support for growing hierarchical Co8FeS8-FeCo2O4/NCNTs core–shell nanostructures (FeCo/NCNTs@CF). We observed improved wettability, specific areal capacitance, and diffusion coefficient, as well as small charge transfer resistance compared with bare CF. MFCs equipped with FeCo/NCNTs@CF displayed a power density of 3.04 W/m2and COD removal amount of 221.0 mg/L/d, about 47.6 and 290.1% improvements compared with that of CF. Biofilm morphology and 16s rRNA gene sequence analysis proved that our anode facilitated the enrichment growth of exoelectrogens. Flavin secretion was also promoted on our hierarchical elelctrode, effectively driving the EET process. This work disclosed that hierarchical nanomaterials modified electrode with tailored physicochemical properties is a promising platform to simultaneously enhance exoelectrogen attachment and EET efficiency for MFCs.

The combination of metallosupramolecular modules (MEMOs) as functional and amphiphiles as structural components is presented in detail to illustrate our current understanding of encapsulation using surfactants, lipids, and dendrimers. The simplicity of fabrication and the availability of the starting components allow this technique as an attractive tool to create new nanoscale molecular materials. The interaction of amphiphiles and MEMOs occurs spontaneously and is driven by the release of counterions as well as electrostatic and hydrophobic interactions.

Polyoxometalates (POMs) comprise a structurally diverse class of inorganic transition metal oxygen clusters which—owing to their unique electronic properties—hold promise for a host of technological applications such as electrochromic windows, sensors, or heterogeneous catalysts, prototypic examples of which will be briefly exemplified. The integration of POMs into functional architectures and devices, however, necessitates the development of general methods that allow positioning these clusters in well-defined supramolecular architectures, thin films, or mesophases. This short review highlights recent advances in the preparation of composite multilayers fabricated by electrostatic layer-by-layer self-assembly (ELSA) of POMs and a variety of water-soluble cationic species, including transition metal complexes, cationic surfactants, polycations and bipolar pyridine.

The electrochemical properties of PW12O$\rm{_{40}^{3-}}$(abbreviated as PW12) anion in poly(ethylene glycol) (PEG) have been studied by cyclic voltammetry, complex impedance and FT‐IR spectroscopy. The PW12anion in PEG‐LiClO4electrolyte shows reasonable facile electrochemistry, and the diffusion coefficients of PW12were measured with microelectrode. It is shown that ionic conductivity of polymer electrolytes based on low molecular weight PEG can be improved by the addition of PW12. The increase of conductivity is coupled with decrease of transient cross‐links density of polymer chains which is evidenced by the downshift of COC stretching mode. The phenomena are explained in view of ion‐ion and ion‐polymer interactions.

The electrochemical properties of PW12O$\rm{_{40}^{3-}}$ (abbreviated as PW12) anion in poly(ethylene glycol) (PEG) have been studied by cyclic voltammetry, complex impedance and FT-IR spectroscopy. The PW12 anion in PEG-LiClO4 electrolyte shows reasonable facile electrochemistry, and the diffusion coefficients of PW12 were measured with microelectrode. It is shown that ionic conductivity of polymer electrolytes based on low molecular weight PEG can be improved by the addition of PW12. The increase of conductivity is coupled with decrease of transient cross-links density of polymer chains which is evidenced by the downshift of C&bond;O&bond;C stretching mode. The phenomena are explained in view of ion-ion and ion-polymer interactions.

In this paper, a new method of fabricating multilayers on a carbon substrate is presented. First, a uniformly charged carbon surface was prepared through molecular design. Then an ultrathin film consisting of layer-pairs of oppositely charged polymeric cationic poly(diallyldimethylammonium chloride) (PDDA) and silicotungstate, SiW₁₂O₄₀⁴⁻ (SiW₁₂), was grown layer-by-layer onto the grafted carbon substrate using a molecular self-assembly technique and an electrochemical method. The technique allows one to prepare highly adherent, dense and smooth films of polyoxometalates with special properties. By combining cyclic voltammetry (CV) and X-ray (XR) reflectometry, it was determined that the average surface density of SiW₁₂ was 2.10 × 10⁻¹⁰ mol cm⁻², and the thickness increase per adsorption of PDDA–SiW₁₂ was 1.7 ± 0.2 nm, indicating that the amount of SiW₁₂ anion per one layer adsorption corresponded to a monolayer coverage. Atomic force microscopy (AFM) was also used to examine the surface morphology and determine the grain size distribution and roughness for multilayer films. An increase in root-mean-square (RMS) surface roughness from 7 to 9 Å was observed as the number of layer-pairs in the film increased from 2 to 6. FTIR results showed that the good stability of the multilayer films was due to Coulomb interactions between the SiW₁₂ anion and the polymeric cations PDDA. Moreover, the multilayer films, in acidic aqueous solution, showed good electrocatalytic activity toward the reduction of NO₂⁻, and the catalytic currents increased with increasing the layer numbers of SiW₁₂ adsorption. These characteristics of the multilayer films might find potential applications in the field of sensors and microelectronics devices.

A composite film containing heteropolyanion was fabricated on gold by attaching the Keggin-type heteropolyanion, PMo12O403−, on a 4-aminothiophenol SAM via Au–S bonding. Reflection FTIR, cyclic voltammetry and XPS were used for the characterization of the composite film. Reflection FTIR studies indicate that there is some Coulombic interaction between PMo12O403−and the surface amino group in the composite film, which greatly improves the film stability and prevents effectively the destructive intermolecular aggregation. The composite film shows three reversible redox couples within the pH range pH≤7.0, attributed to three two-electron and two-proton electrochemical reduction–oxidation processes of PMo12O403−. Compared with PMo12O403−in the solution, the PMo12O403−of the composite film electrode can exist in a larger pH range, and shows smaller peak-to-peak separation, and more reversible reaction kinetics. Moreover, the composite film obtained shows a good catalytic activity for the reduction of BrO3−.

A novel organic‐inorganic composite film was formed by attaching Keggin‐type heteropolyanion, SiW12O404−(devoted briefly as SiW12), on a glassy carbon electrode derivatized by 4‐aminophenyl group. The composite film has an ionic bonding character between SiW12and the surface amino group, which greatly improves the film stability and exhibits a more reversible electrochemical behavior. The modified electrode offers an excellent and stable electrocatalytic response for the reduction of nitrite. Possible mechanism was provided for the reaction of nitrite with SiW12O404−/aminophenyl composite film.

Narrowing the mechanical mismatch between biological tissues (typically soft) and neural interfaces (hard) is essential for maintaining signal quality for the electrical recording of neural activity. However, only a few materials can satisfy all requirements for such electronics, which need to be both biocompatible and sufficiently soft. Here, a highly stretchable electrode array (SEA) is introduced, based on the liquid metal–polymer conductor (MPC), achieving high mechanical flexibility and good cytocompatability for neural interfaces. By utilizing the MPC, the SEA exhibits high stretchability (≈100%) and excellent cycling stability (>400 cycles). The cytocompatability of the SEA can allow for long‐term culturing of primary neurons and enable signal recording of primary hippocampal neurons. In the future, the SEA could serve as a reliable and robust platform for diagnostics in neuronal tissues and greatly advance brain–machine interfaces. Based on the liquid metal–polymer conductor, a stretchable electrode array (SEA) is developed for in vitro electrophysiology. The SEA exhibits high stretchability and stable electrical properties. The excellent cytocompatability of the SEA can allow for long‐term culturing of primary neurons and enable signal recording of primary hippocampal neurons.

Convenient and rapid self-measurement of the glucose level in the body is of great significance for diabetics to know their health conditions in time. In view of this, a polymer functionalized graphene field-effect transistor (P-GFET) portable biosensing device is demonstrated for glucose monitoring. The polymer is synthesized by acrylamide (AAm)/3-acrylamidophenylboronic acid (AAPBA)/N, N-Dimethylaminopropyl acrylamide (DMAAPA). In the presence of glucose, the P-GFET shows Dirac point shifts and current changes, as a result of the covalent bond between glucose and AAPBA in the synthesized polymer on graphene. The sensitivity of this P-GFET sensor can increase compared while the density of AAPBA in polymer increases. The used sensor could regain the detection capability after hydrochloric acid treatment due to the reversible reaction between polymer and glucose. Additionally, the chemisorption interaction between polymer and glucose, which is stronger than physisorption interaction with other objects in urine, has been supported by the density functional theory study. The P-GFET shows high sensitivity of 822 μA*cm−2*mM−1with a limit of detection (LOD) of 1.9 μM during human urine glucose monitoring. The sensor holds a detection range of 0.04 to 10 mM and good reusability over 20 times. With the customized portable real-time measurement capability in urine, our P-GFET sensor can offer advantages over current glucose detection methods.

Molecular or supramolecular systems capable of electro- and photostimulated color changes are still rare. We present a device design based on an electrostatic complex of a nanoscopic polyoxometalate cluster and a polyelectrolyte. The coating reversibly changes color from transparent to blue by photo- and/or electroinduced stimulation. The choice of the components results in perfect transparency over the entire visible range, a large optical response, reversible operation, and excellent stability.

A highly organized phenyl-capped teraniline (PC-teraniline) film at the molecular level was fabricated on carbon surfaces by electrochemical reduction of diazonium salts. Cyclic voltammetry (CV), scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS) were employed for the characterization of the film.

The polyoxometalate cluster [Coii₄(H₂O)₂P₄W₃₀O₁₁₂]16− (Co-POM) embedded in a self-assembled polyelectrolyte matrix shows a remarkable pH dependence of its electrochemical response, opening a route to use Co-POM as a molecular probe or to fabricate pH microelectrodes.