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Nanoporous Ca3Co4O9 exhibits high thermoelectric properties and low thermal conductivity and can be made mechanically flexible by nanostructural design. To improve the mechanical flexibility with retained thermoelectric properties near room temperature, however, it is desirable to incorporate an organic filler in this nanoporous inorganic matrix material. Here, double-layer nanoporous Ca3Co4O9/PEDOT:PSS thin films were synthesized by spin-coating PEDOT:PSS into the nanopores. The obtained hybrid films exhibit high Seebeck coefficient (~+130 mu V/K) and thermoelectric power factor (0.75 mu W cm(-1) K-2) at room temperature with no deterioration in electrical properties after cyclic bending tests (98% preservation of electrical conductivity after 1000 cycles bending to a bending radius of 3 mm). Compared with the nanoporous Ca3Co4O9 thin film, the mechanical flexibility of the hybrid film can be effectively improved after hybrid with PEDOT:PSS with only a slight decrease of the thermoelectric properties. Funding Agencies|Knut and Alice Wallenberg Foundation [KAW 2020.0196]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Link?ping University [2009 00971]; Swedish Research Council [2021-03826]; Swedish Energy Agency [46519-1]; China Scholarship Council

Gelatin is an excellent gelling agent and is widely employed for hydrogel formation. Because of the poor mechanical properties of gelatin when dry, gelatin-aerogels are comparatively rare. Herein we demonstrate that protein nanofibrils can be employed to improve the mechanical properties of gelatin aerogels, and the materials can moreover be functionalized with a an electrically conductive polyelectrolyte resulting in formation of an elastic electrically conductive aerogel that can be employed as a piezoresistive pressure sensor. The aerogel sensor shows a good linear relationship in a wide pressure range (1.8-300 kPa) with a sensitivity of 1.8 kPa(-1). This work presents a convenient way to produce electrically conductive elastic aerogels from low-cost protein precursors.

Continuous harvesting of electricity from the ambient environment has attracted great attention as a facile approach to green and sustainable energy. Natural water evaporation-driven electricity generators with active materials from economical and environment-friendly sources are highly sought after. Herein, we present devices made from a combination of protein nanofibrils (PNFs) and low-cost graphene nanoplatelets (GNPs) that can be employed for electricity generation, simply by partly inserting the device into evaporating standing water. The origin of the electricity generation can be explained by the ionovoltaic effect where ionic motion, driven by evaporating water, leads to movement of charge carriers in the electrically conductive GNP-phase. Moreover, the device performance can be improved by adding a small amount of salt to the active layer. A device, composed of GNP:PNF:AlCl3, produces a sustained voltage of about 0.48 V, and a current of 89 nA. Furthermore, the device can tolerate saline water, with only a modest decrease of voltage, which provides potential for harvesting electricity from both evaporating saline water and fresh water. Funding Agencies|Formas [2019-00679]; China Scholarship Council

Herein we demonstrate a novel way of modifying the colloidal stability of proteins by the presence of hydrophobic molecules. A protein capable of self-assembly into protein nanofibrils (PNFs) is milled with a hydrophobic molecular material. Upon dissolution in acidic water followed by heating, the proteins are converted into PNFs containing hydrophobic dyes. When aqueous dispersions of such PNFs are heated, films are formed at the air-water interface. The films contain ordered, optically anisotropic domains, and the shape of the reaction vessel can influence the PNF packing. We demonstrate the generality of the process by employing PNFs derived from the three proteins bovine insulin (INS), beta-lactoglobulin (BLG), and hen egg white lysozyme (HEWL) in combination with the dyes alpha-sexithiophene (6T) and 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM). As individual dye molecules are oriented along the long PNF axis, whole ensembles of dyes become aligned and, as a result, display emission of polarized light. Moreover, in the case of PNFs stained with DCM, stimulated emission is demonstrated. Funding Agencies|China Scholarship Council (CSC)China Scholarship Council; Carl Tryggers foundation; Polish National Agency for Academic Exchange Bekker programmePolish National Agency for Academic Exchange (NAWA); Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009-00971]

Mechanochemical transformations have made chemists enter unknown territories, forcing a different chemistry perspective. While questioning or revisiting familiar concepts belonging to solution chemistry, mechanochemistry has broken new ground, especially in the panorama of organic synthesis. Not only does it foster new "thinking outside the box", but it also has opened new reaction paths, allowing to overcome the weaknesses of traditional chemistry exactly where the use of well-established solution-based methodologies rules out progress. In this Review, the reader is introduced to an intriguing research subject not yet fully explored and waiting for improved understanding. Indeed, the study is mainly focused on organic transformations that, although impossible in solution, become possible under mechanochemical processing conditions, simultaneously entailing innovation and expanding the chemical space.

Hybrids between biopolymeric materials and low-cost conductive carbon-based materials are interesting materials for applications in electronics, potentially reducing the need for materials that generate environmentally harmful electronic waste. Herein we investigate a scalable ball-milling method to form graphene nanoplatelets (GNPs) by milling graphite flakes with aqueous dispersions of proteins or protein nanofibrils (PNFs). Aqueous GNP dispersions with high concentrations (up to 3.2 mg mL–1) are obtained under appropriate conditions. The PNFs/proteins help to exfoliate graphite and stabilize the resulting GNP dispersions by electrostatic repulsion. PNFs are prepared from hen egg white lysozyme (HEWL) and β-lactoglobulin (BLG). The GNP dispersions can be processed into free-standing films having an electrical conductivity of up to 110 S m–1. Alternatively, the GNP dispersions can be drop-cast on PET substrates, resulting in mechanically flexible films having an electrical conductivity of up to 65 S m–1. The drop-cast films are investigated regarding their thermoelectric properties, having Seebeck coefficients of about 50 μV K–1. By annealing drop-cast films and thus carbonizing residual PNFs, an increase of electrical conductivity, coupled with a modest decrease in Seebeck coefficient, is obtained resulting in materials displaying power factors of up to 4.6 μW m–1 K–2., A green method for preparation of graphene nanoplatelets is presented and the thermoelectric properties of the GNP materials are investigated.

Deoxyribonucleic acid (DNA) and a self-doped conjugated polyelectrolyte, poly(4-(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl-methoxy)-1-butanesulfonic acid (PEDOT-S), are assembled for organic optoelectronics and bioelectronics. The DNA’s helix–coil phase transition in water is studied as a function of composition by thermo-optical analysis. DNA and PEDOT-S are functionalized by using a surfactant, cetyltrimethylammonium chloride (CTMA), and DNA:CTMA, PEDOT-S:CTMA, and DNA:CTMA:PEDOT-S:CTMA complexes were characterized regarding thermal, optical, morphological, and structural properties. Finally, DNA and DNA:PEDOT-S mixtures are processed in water for fabricating organized films through brushing. The electrical properties of these films are characterized using an interdigitated electrode. The films show an electronic conductivity of ∼10–6–10–5 S/cm in a range of semiconductors.

A green, though black, sustainable and low-cost carbon material-charcoal produced from wood-is developed for electricity storage. Charcoal electrodes are fabricated by ball-milling charcoal and adding protein nanofibril binders. The charcoal electrode presents a capacitance of 360 F g(-1) and a conductivity of 0.2 S m(-1). A pair of redox peaks is observed in the cyclic voltammetry and assigned to originate from quinone groups. Compared with other wooden electrodes, these charcoal electrodes display better cycling stability with 88% capacity retention after 1000 cycles. Their discharge capacity is 2.5 times that of lignosulfonate/graphite hybrid electrodes. Funding Agencies|Knut and Alice Wallenberg Foundation (KAW)Knut & Alice Wallenberg Foundation; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]

Mechanochemistry is a versatile methodology that can be employed both for covalent bond formation in organic synthesis as well as a mediator to allow preparation novel colloidal dispersions for drug delivery. Herein, ball-milling was employed for the solid-state preparation of fluorescent hydrophobic hydantoins, followed by the unprecedented mechanochemically-mediated complexation of hydrophobic hydantoins within hydrophilic protein beta-lactoglobulin (BLG) and BLG nanofibrils (BLGNFs). These hydantoin:protein materials were in turn incorporated into hydrogels. The effect of incorporation of hydantoins into proteins, as well as the effect of protein structure, on the release properties were then investigated. The conversion of BLG to BLGNFs led to a more sustained release demonstrating that heat treatment of BLG into BLGNFs could be employed to modify release properties. To the best of our knowledge, this is the first example where protein : hydantoin complexes were prepared by mechanochemical methodology and mechanochemistry was combined with self-assembly in order to prepare protein nanomaterials for drug-delivery applications. In addition, the use of the developed protein materials is not limited to delivery of drugs but can for example be employed as components of smart food (delivery of nutrients) or release systems of pesticides. Funding Agencies|COST (European Cooperation on Science and Technology) [CA18112]; Region Occitanie (France) [ESR_PREMAT-00262]; China Scholarship CouncilChina Scholarship Council

The layered cobaltates A(x)CoO(2) (A = Li, Na, Ca, Ba, Sr) are of interest for energy applications such as thermoelectrics and batteries. However, it is challenging to obtain these phases in pure from as thin films. Here, phase-pure CaxCoO2 (x similar to 0.5) thin films were obtained by annealing of Ca(OH)(2)/Co3O4 multilayers made by moisture treatment of sputter-deposited CaO/Co3O4 multilayer films. The pure CaxCoO2 thin films exhibit an average optical transmittance of approximately 36% in the visible region and greater than 70% in the near-infrared (NIR) region. In addition, the electrical conductivity can be increased by incorporating a secondary Ca3Co4O9 phase into the CaxCoO2 thin film without large changes in optical properties and Seebeck coefficient. (C) 2021 The Authors. Published by Elsevier Ltd. Funding Agencies|Knut and Alice Wallenberg Foundation through the Wallenberg Academy Fellows program [KAW 2020.0196]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [200900971]; Swedish Energy AgencySwedish Energy Agency [46519-1]; China Scholarship CouncilChina Scholarship Council

The development towards a sustainable society requires a radical change of many of the materials we currently use. Besides the replacement of plastics, derived from petrochemical sources, with renewable alternatives, we will also need functional materials for applications in areas ranging from green energy and environmental remediation to smart foods. Proteins could, with their intriguing ability of self-assembly into various forms, play important roles in all these fields. To achieve that, the code for how to assemble hierarchically ordered structures similar to the protein materials found in nature must be cracked. During the last decade it has been demonstrated that amyloid-like protein nanofibrils (PNFs) could be a steppingstone for this task. PNFs are formed by self-assembly in water from a range of proteins, including plant resources and industrial side streams. The nanofibrils display distinct functional features and can be further assembled into larger structures. PNFs thus provide a framework for creating ordered, functional structures from the atomic level up to the macroscale. This review address how industrial scale protein resources could be transformed into PNFs and further assembled into materials with specific mechanical and functional properties. We describe what is required from a protein to form PNFs and how the structural properties at different length scales determine the material properties. We also discuss potential chemical routes to modify the properties of the fibrils and to assemble them into macroscopic structures.

A combination of mechanochemistry and aqueous self-assembly is employed to prepare protein nanofibrils (PNFs) functionalized with perylene diimide (PDI) dyes. These materials are then mixed with poly(vinyl alcohol) (PVA) and casted into bioplastic films. The functionalization process not only results in luminescent hybrid materials, but the presence of the dye modifies the physical properties of the PNFs. Films formed from PNFs functionalized with PDIs display anisotropic organization, which enables emission of polarized light. Crucially, the presence of PDI dyes improves the stability of PNF-PVA films in water and moreover the films are processable when wet. By applying water, films can be glued together or self-healed by applying water. Mechanochemical methodology can thus be employed for modifying properties of protein materials. This represents a new highly flexible and novel strategy for tuning both properties and functionality of protein materials. Funding Agencies|Formas [2019-00679]; China Scholarship Council

The potential of area selective deposition (ASD) with a newly developed chemical vapor deposition method, which utilize plasma electrons as reducing agents for deposition of metal films, is demonstrated using temperature sensitive polymer-based masking materials. The masking materials tested were polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), polystyrene (PS), parafilm, Kapton tape, Scotch tape, and office paper. The masking materials where all shown to prevent film growth on the masked area of the substrate without being affected by the film deposition process. X-ray photoelectron spectroscopy analysis confirms that the film deposited consist mainly of metallic iron, whereas no film material is found on the masked areas after mask removal. SEM analysis of films deposited with non‑adhesive masking materials show that film growth extended for a small distance underneath the masking material, indicating that the CVD process with plasma electrons as a reducing agent is not a line-of-sight deposition technique. The reported methodology introduces an inexpensive and straightforward approach for ASD that opens for exciting new possibilities for robust and less complex area selective metal‑on‑metal deposition.

Lignin has been proposed as electricity storage materials due to the redox activity of quinone (Q) and hydroquinone (QH(2)) groups, which can be formed in lignin. Scalable and low-cost lignosulfonate (LS)/graphite hybrid material electrodes have been developed. It is important to investigate the self discharge mechanism for these electrodes since a high self-discharge rate was observed, which results in loss of energy density and power density. In this work, self-discharge measurements and models are applied to clarify the self-discharge mechanism of the LS/graphite electrodes. A combination of diffusion controlled, activation controlled and charge equilibration mechanisms are indicated during the self discharge process at different charging voltages, due to the faradaic reactions of the Q/QH(2) confined in the electrodes. Our work contributes deeper understanding of the structure and the self-discharge mechanisms of the biopolymer/graphite hybrid electrodes. (C) 2021 The Author(s). Published by Elsevier Ltd.

potential of area selective deposition (ASD) with a newly developed chemical vapor deposition method, which utilize plasma electrons as reducing agents for deposition of metal-containing films, is demonstrated using temperature sensitive polymer-based masking materials. The masking materials tested were polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), polystyrene (PS), parafilm, Kapton tape, Scotch tape, and office paper. The masking materials were all shown to prevent film growth on the masked area of the substrate without being affected by the film deposition process. X-ray photoelectron spectroscopy analysis confirms that the films deposited consist mainly of iron, whereas no film material is found on the masked areas after mask removal. SEM analysis of films deposited with non-adhesive masking materials show that film growth extended for a small distance underneath the masking material, indicating that the CVD process with plasma electrons as reducing agents is not a line-of-sight deposition technique. The reported methodology introduces an inexpensive and straightforward approach for ASD that opens for exciting new possibilities for robust and less complex area selective metal-on-metal deposition.

Counterion exchange has been introduced as a method to modify properties of anionic conjugated polyelectrolyte (CPE) blends. Blending of two self-doped CPEs having metallic and semiconducting behavior has been achieved from two different solvents, by exchanging the counterion of the metallic component. Different blending conditions lead to films exhibiting different optical properties, depending on the aggregation states of the CPEs. Conductance responses for the blends showed the opportunity to tune threshold voltage of the films both by blending and counterion exchange. Therefore, the blends have been exploited for the fabrication of accumulation mode organic electrochemical transistors. These devices exhibit short switching times and high transconductance, up to 15.3 mS, as well as high stability upon fast pulsed cycles, retaining 88% of the drain currents after 2 × 103 cycles.

This paper presents the work carried out within the European project RENAISSANCE-ITN, which was dedicated to the development of innovative polyelectrolytes for energy and environmental applications. Within the project different types of innovative polyelectrolytes were synthesized such as poly(ionic liquid)s coming from renewable or natural ions, thiazolium cations, catechol functionalities or from a new generation of cheap deep eutectic monomers. Further, macromolecular architectures such as new poly(ionic liquid) block copolymers and new (semi)conducting polymer/polyelectrolyte complexes were also developed. As the final goal, the application of these innovative polymers in energy and the environment was investigated. Important advances in energy storage technologies included the development of new carbonaceous materials, new lignin/conducting polymer biopolymer electrodes, new iongels and single-ion conducting polymer electrolytes for supercapacitors and batteries and new poly(ionic liquid) binders for batteries. On the other hand, the use of innovative polyelectrolytes in sustainable environmental technologies led to the development of new liquid and dry water, new materials for water cleaning technologies such as flocculants, oil absorbers, new recyclable organocatalyst platforms and new multifunctional polymer coatings with antifouling and antimicrobial properties. All in all this paper demonstrates the potential of poly(ionic liquid)s for high-value applications in energy and enviromental areas. © 2017 Society of Chemical Industry

Herein we utilize insulin to prepare amyloid based chiral heliceswith either right or left handed helicity. We demonstrate that thehelices can be utilized as structural templates for the conductingpolymer alkoxysulfonate poly(ethylenedioxythiophene) (PEDOT-S).The chirality of the helical assembly is transferred to PEDOT-S asdemonstrated by polarized optical microscopy (POM) and CircularDichroism (CD). Analysis of the helices by conductive atomic force(c-AFM) shows significant conductivity. In addition the morphologyof the template structure is stabilized by PEDOT-S. Theseconductive helical structures represent promising candidates in ourquest for THz resonators. Funding agencies: Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [SFO-Mat-LiU 2009-00971]; Strategic Research Foundation through the project OPEN; Knut and Alice Wallenberg foundation; Wallenberg Scholar gran

Lignin is a promising candidate for energy storage because of its abundance, wide geographic distribution, and low cost as it is mainly available as a low value product from processing of wood into paper pulp. Lignin contains large amounts of potential quinone groups, which can be oxidized and reduced in a two electron process. This redox reaction makes lignin suitable for charge storage. However, lignin is insulating and therefore conductive materials are necessary in lignin electrodes, for whom the cost of the conductive materials hinders the scalable application. Among the organic conductive materials, graphite is one of the cheapest and is easily acquired from nature. In this work, we combine graphite and lignosulfonate (LS) and fabricate LS/graphite organic electrodes under a solvent-free mechanical milling method, without additives. The graphite is sheared into small particles with a size range from 50 nm to 2000 nm. Few-layer graphene is formed during the ball milling process. The LS/graphite hybrid material electrodes with primary stoichiometry of 4/1 (w/w) gives a conductivity of 280 S m

Hydrophobic, self-doped conjugated polyelectrolytes (CPEs) are introduced as highly stable active materials for organic electrochemical transistors (OECTs). The hydrophobicity of CPEs renders films very stable in aqueous solutions. The devices operate at gate voltages around zero and show no signs of degradation when operated for 104 cycles under ambient conditions. These properties make the produced OECTs ideal devices for applications in bioelectronics.

Humic acid (HA) is a biopolymer formed from degraded plants, making it a ubiquitous, renewable, sustainable, and low cost source of biocarbon materials. HA contains abundant functional groups, such as carboxyl-, phenolic/alcoholic hydroxyl-, ketone-, and quinone/hydroquinone (Q/QH2)-groups. The presence of Q/QH2 groups makes HA redox active and, accordingly, HA is a candidate material for energy storage. However, as HA is an electronic insulator, it is essential to combine it with conductive materials in order to enable fabrication of HA electrodes. One of the lowest cost types of conductive materials that can be considered is carbon-based conductors such as graphite. Herein, we develop a facile method allowing the biocarbon to meet carbon, HA (in the form of a sodium salt) is mixed with graphite by a solvent-free mechanochemical method involving ball milling. Few-layer graphene sheets are formed and the HA/graphite mixtures can be used to fabricate HA/graphite hybrid material electrodes. These electrodes exhibit a conductivity of up to 160 S&middot, m&minus, 1 and a discharge capacity as large as 20 mAhg&minus, 1. Our study demonstrates a novel methodology enabling scalable fabrication of low cost and sustainable organic electrodes for application as supercapacitors.

In this work, we report a novel protein-based nanoprobe (PNP) that can be employed for quantitative analysis of Cu2+ in pure water medium and real samples. Structurally, the proposed nanoprobe comprises a biofriendly protein (hen egg-white lysozyme (HEWL)) and a Cu2+-specific chromogenic agent, where HEWL acts as a nanocarrier encapsulating a structurally tailored rhodamine B derivate. The resulting PNP exhibits a hydrodynamic diameter of ~ 106 nm and efficiently disperses in water, enabling the detection of Cu2+ in pure aqueous systems without the aid of any organic co-solvents. The high sensitivity and selectivity of PNP allow the colorimetric detection of Cu2+ in the presence of other metal interferents with a low detection limit of 160 nM. The satisfying recovery of trace level Cu2+ in environmental samples demonstrate the great potential of employing PNP for the determination of Cu2+ in actual applications. Most importantly, the simple co-grinding method employing proteins and chromogenic agents provides a novel strategy to generate sensing systems that are useful detection of pollutants in aqueous samples.

The redox reactions of quinones can be used in electrical energy storage systems. Biopolymers are one of the important sources for quinones due to sustainability and low cost. In this work, biomass materials that contain a large fraction of potential quinone groups are used to directly fabricate biomass/graphite hybrid material electrodes, without extraction or separation of the redox active components from other elements. Among these biomass electrodes based on barks, the bark from holm oak (Quercus ilex) and graphite hybrid electrode exhibits a discharge capacity of 20 mAh g(-1), with 68% capacity retention after 1000 cycles. Moreover, various quinone chemicals from the biological world are used to generate the quinone/graphite hybrid material electrodes that display higher quinone loadings at the carbon electrodes. The alizarin/graphite hybrid material electrode presents a capacity of 70 mAh g(-1), which is approximate to 30 times higher than that of the graphite electrode. It is demonstrated that barks and quinones are capable of exfoliating graphite into few-layer graphene sheets with reduced crystallite size. Processing into electrodes is facilitated by the use of another biopolymer, proteins in the form of misfolded protein fibrils, which also help to improve the available charge in electrodes formed from biomass or quinones. Funding Agencies|Knut and Alice Wallenberg foundation (KAW)Knut & Alice Wallenberg Foundation; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]; China Scholarship Council (CSC)China Scholarship Council

In the following report, a conjugated polyelectrolyte (CPE) blend has been introduced for the first time as a fluorescent probe of membrane organization. Insertion of the blend into the lipid doubl ...

Many proteins undergoe self-assembly into fibrillar structures known as amyloid fibrils. During the self-assembly process, related structures known as spherulites can be formed. Herein we report a facile method where the balance between amyloid fibrils and spherulites can be controlled by stirring of the reaction mixture during the initial stages of the self-assembly process. Moreover, we report how this methodology can be used to prepare non-covalently functionalized amyloid fibrils. By stirring the reaction mixture continuously or for a limited time during the lag phase, the fibril length, and hence the propensity to form liquid crystalline phases, can be influenced. This phenomena is utilized in order to prepare films consisting of aligned protein fibrils incorporating the laser dye Nile red. The resulting films display polarized Nile red fluorescence.

Developing sustainable organic electrode materials for energy storage applications is an urgent task. We present a promising candidate based on the use of lignin, the second most abundant biopolymer in nature. This polymer is combined with a conducting polymer, where lignin as a polyanion can behave both as a dopant and surfactant. The synthesis of PEDOT/Lig biocomposites by both oxidative chemical and electrochemical polymerization of EDOT in the presence of lignin sulfonate is presented. The characterization of PEDOT/Lig was performed by UV-Vis-NIR spectroscopy, FTIR infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, cyclic voltammetry and galvanostatic charge–discharge. PEDOT doped with lignin doubles the specific capacitance (170.4 F g−1) compared to reference PEDOT electrodes (80.4 F g−1). The enhanced energy storage performance is a consequence of the additional pseudocapacitance generated by the quinone moieties in lignin, which give rise to faradaic reactions. Furthermore PEDOT/Lig is a highly stable biocomposite, retaining about 83% of its electroactivity after 1000 charge/discharge cycles. These results illustrate that the redox doping strategy is a facile and straightforward approach to improve the electroactive performance of PEDOT.

Herein, we investigate the suitability of hen egg-white lysozyme (HEWL) as a protein matrix for dispersal of various hydrophobic dyes. Moreover, we investigate the use of a mixer mill for grinding operation as an alternative to hand grinding by mortar and pestle. HEWL and various dyes are mixed by mechanochemistry, and the resulting composite material is dissolved in aqueous acid. The samples are then exposed to conditions promoting self-assembly of HEWL into protein nanofibrils (PNFs). The effect of PNF formation on dye photophysics is investigated by spectroscopic examination by absorption and luminescence spectroscopy, and product morphology is examined by scanning electron microscopy. The self-assembly process results in protein nanofibrils functionalized with luminescent dyes. Such structures may find future applications in various devices for light emission. In addition, we demonstrate that the anticancer drug camptothecin can be incorporated into protein nanofibrils giving materials that can find application as drug delivery agents. Funding Agencies|China Scholarship Council; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009-00971]

Two self-doped conjugated polyelectrolytes, having semiconducting and metallic behaviors, respectively, have been blended from aqueous solutions in order to produce materials with enhanced optical and electrical properties. The intimate blend of two anionic conjugated polyelectrolytes combine the electrical and optical properties of these, and can be tuned by blend stoichiometry. In situ conductance measurements have been done during doping of the blends, while UV–vis and EPR spectroelectrochemistry allowed the study of the nature of the involved redox species. We have constructed an accumulation/depletion mode organic electrochemical transistor whose characteristics can be tuned by balancing the stoichiometry of the active material.

Herein we report on the investigation of self-assembled protein nanofibrils functionalized with metallic organic compounds. We have characterized the electronic behaviour of individual nanowires using conductive atomic force microscopy. In order to follow the self assembly process we have incorporated fluorescent molecules into the protein and used the energy transfer between the internalized dye and the metallic coating to probe the binding of the polyelectrolyte to the fibril.

The presence of a fluorescent hydrophobic oligothiophene (6T) dramatically influences the process where insulin self-assembles into spherulites, resulting in large (up to 1.4 mm) fluorescent spherulites.

Herein, we demonstrate that it is possible to rapidly screen hydrophobic fluorescent aromatic molecules with regards to their properties as amyloid probes. By grinding the hydrophobic molecule with the amyloidogenic protein insulin, we obtained a water-soluble composite material. When this material is dissolved and exposed to conditions promoting amyloid formation, the protein aggregates into amyloid fibrils incorporating the hydrophobic molecule. As a result, changes in the fluorescence spectra of the hydrophobic molecule can be correlated to the formation of amyloid fibrils, and the suitability of the hydrophobic molecular skeleton as an amyloid probe can thus be assessed. As a result, we discovered two new amyloid probes, of which one is the well-known laser dye DCM. The grinding method can also be used for rapid preparation of novel composite materials between dyes and proteins, which can be used in materials science applications such as organic electronics and photonics.

A number of human diseases are associated with the formation of insoluble protein aggregates commonly known as amyloid fibrils or amyloid plaques. Similar materials can be prepared in vitro resulting in so-called amyloid-like fibrils. Herein is discussed how to prepare such fibrils labeled with magnetic nanoparticles. Such materials have the potential to be used as magnetic probes for magnetic resonance imaging applications.

Several organic materials and blends have been studied with the use of electron tomography. Tomography reconstructions of active layers of organic solar cells, where various preparation techniques ...

In this review we discuss our efforts in using protein nanowires (amyloid fibrils) as structural templates for use in organic electronics applications, mainly focusing on organic light-emitting diodes (OLEDs). We discuss different ways of functionalising amyloid fibrils. In one method, the amyloid fibril is used to organise luminescent polymers. We also discuss an alternative preparative method, resulting in amyloid-like materials functionalised with phosphorescent organometallic complexes. We discuss the incorporation of such materials in organic electronics devices, such as OLEDs. When amyloid fibrils are integrated into the OLED active layer, consisting of an electroluminescent blue-emitting polyfluorene, the efficiency of the device increases by a factor of 10. Furthermore, when amyloid fibrils incorporating phosphorescent metal complexes are used, the phosphorescent guest functions more efficiently than in the corresponding case where naked metal complexes are used. By preparing amyloid fibrils incorporating green- and red-emitting phosphorescent complexes, and combining these with blue-emitting polyfluorene, we can fabricate devices for white-light emission. The origin of the effects of the biomaterial on device performance is discussed.

A method to prepare amyloid-like fibrils functionalized with magnetic nanoparticles has been developed. The amyloid-like fibrils are prepared in a two step procedure, where insulin and magnetic nanoparticles are mixed simply by grinding in the solid state, resulting in a water soluble hybrid material. When the hybrid material is heated in aqueous acid, the insulin/nanoparticle hybrid material self assembles to form amyloid-like fibrils incorporating the magnetic nanoparticles. This results in magnetically labeled amyloid-like fibrils which has been characterized by Transmission Electron Microscopy (TEM) and electron tomography. The influence of the aggregation process on proton relaxivity is investigated. The prepared materials have potential uses in a range of bio-imaging applications.

A bi-functional mesoporous silica material, containing both carboxylic acid and amino groups, acts as a catalyst for the reaction between aldehydes and carbon nucleophiles. We demonstrate reaction conditions under which even aldehydes containing deactivating electron donating groups, or sterically demanding substituents, undergo the catalyzed reaction with acetone, affording primarily the condensation products. Moreover, we demonstrate that acetophenone and ethyl methyl ketone can replace acetone as nucleophile. The bi-functional mesoporous silica is a convenient catalyst, as it is simple to remove from the reaction media, thereby facilitating workup.

Many proteins undergoe self-assembly into fibrillar structures known as amyloid fibrils. During the self-assembly process, related structures known as spherulites can be formed. Herein we report a facile method where the balance between amyloid fibrils and spherulites can be controlled by stirring of the reaction mixture during the initial stages of the self-assembly process. Moreover, we report how this methodology can be used to prepare non-covalently functionalized amyloid fibrils. By stirring the reaction mixture continuously or for a limited time during the lag phase, the fibril length, and hence the propensity to form liquid crystalline phases, can be influenced. This phenomena is utilized in order to prepare films consisting of aligned protein fibrils incorporating the laser dye Nile red. The resulting films display polarized Nile red fluorescence.

Electrical interfaces between biological cells and man-made electrical devices exist in many forms, but it remains a challenge to bridge the different mechanical and chemical environments of electronic conductors (metals, semiconductors) and biosystems. Here we demonstrate soft electrical interfaces, by integrating the metallic polymer PEDOT-S into lipid membranes. By preparing complexes between alkyl-ammonium salts and PEDOT-S we were able to integrate PEDOT-S into both liposomes and in lipid bilayers on solid surfaces. This is a step towards efficient electronic conduction within lipid membranes. We also demonstrate that the PEDOT-S@alkyl-ammonium: lipid hybrid structures created in this work affect ion channels in the membrane of Xenopus oocytes, which shows the possibility to access and control cell membrane structures with conductive polyelectrolytes. Funding Agencies|Knut and Alice Wallenberg Foundation; Swedish Research Council

Electrophilic allylic substitution of allylstannanes with aldehyde and imine substrates could be achieved by employment of palladium pincer complex catalysts. It was found that the catalytic activity of the pincer complexes is highly dependent on the ligand effects. The best results were obtained by employment of PCP pincer complexes with weakly coordinating counterions. In contrast to previous applications for electrophilic allylic substitutions via bisallylpalladium complexes, the presented reactions involve monoallylpalladium intermediates. Thus, employment of pincer complex catalysts extends the synthetic scope of the palladium-catalyzed allylic substitution reactions. Moreover, use of these catalysts eliminates the side reactions occurring in transformations via bisallylpalladium intermediates. The key intermediate of the electrophilic substitution reaction was observed by (1)H NMR spectroscopy. This intermediate was characterized as an eta(1)-allyl-coordinated pincer complex. Density functional theory (DFT) modeling shows that the electrophilic attack can be accomplished with a low activation barrier at the gamma-position of the eta(1)-allyl moiety. According to the DFT calculations, this reaction takes place via a six-membered cyclic transition-state (TS) structure, in which the tridentate coordination state of the pincer ligand is preserved. The stereoselectivity of the reaction could be explained on the basis of the six-membered cyclic TS model.

The mechanism of the η3 → η1 → η3 isomerization of (η3-allyl)palladium complexes occurring as catalytic intermediates in important synthetic transformations has been studied by applying density functional theory at the B3PW91(DZ+P) level. It was found that under catalytic conditions, in the condensed phase, the isomerization process involves tetracoordinated (η1-allyl)palladium intermediates. In these intermediates a solvent molecule or another ancillary ligand coordinates to palladium. The stability of the (η1-allyl)palladium intermediates critically depends on the electronic effects and on the coordination ability of the solvent molecules and the ancillary ligands. The theoretical calculations indicate a dσ → π* type hyperconjugative interaction occurring in the η1-allyl moiety of the intermediary complexes. These hyperconjugative interactions influence the structure of the complexes and the activation barrier to rotation through the C1−C2 bond. Alkyl substitution of the metalated carbon leads to destab...

Molecular transport through nanoscale pores in films, membranes and wall structures is of fundamental importance in a number of physical, chemical and biological processes(1-6). However, there is a lack of experimental methods that can obtain information on the structure and orientation of the molecules as they pass through the pore, and their interactions with the pore during passage. Imaging with a transmission electron microscope is a powerful method for studying structural changes in single molecules as they move(7,8) and for imaging molecules confined inside carbon nanotubes(9). Here, we report that such imaging can be used to observe the structure and orientation of a hydrocarbon chain as it passes through nanoscale defects in the walls of a single-walled carbon nanotube to the vacuum outside, and also to study the interactions between the chain and the nanopore. Based on experiments at 293 K and 4 K we conclude that the major energy source for the molecular motions observed at 4 K is the electron beam used for the imaging.

[chemical reaction: see text]. A variety of phosphorous compounds such as secondary phosphines, phosphine oxides, phosphinates, and phosphonates undergo addition to [60]fullerene in DMSO/C6H5Cl without extraneous reagents to produce hydrophosphorylated fullerene derivatives in moderate to high yield.