Graphene has exceptional mechanical and electronic properties, but its hydrophobic nature is a disadvantage in biologically related applications. Amyloid fibrils are naturally occurring protein aggregates that are stable in solution or under highly hydrated conditions, have well-organized supramolecular structures and outstanding strength. Here, we show that graphene and amyloid fibrils can be combined to create a new class of biodegradable composite materials with adaptable properties. This new composite material is inexpensive, highly conductive and can be degraded by enzymes. Furthermore, it can reversibly change shape in response to variations in humidity, and can be used in the design of biosensors for quantifying the activity of enzymes. The properties of the composite can be fine-tuned by changing the graphene-to-amyloid ratio.

Conventional metal-organic framework (MOF) powders have periodic micro/mesoporous crystalline architectures tuned by their three-dimensional coordination of metal nodes and organic linkers. To add practical macroscopic shapeability and extrinsic hierarchical porosity, fibrous MOF aerogels were produced by synthesizing MOF crystals on the template of TEMPO-cellulose nanofibrils. Cellulose nanofibrils not only offered extrinsic porosities and mechanical flexibility for the resultant MOF aerogels, but also shifted the balance of nucleation and growth for synthesizing smaller MOF crystals, and further decreased their aggregation possibilities. Thanks to their excellent shapeability, hierarchical porosity up to 99%, and low density below 0.1 g/cm, these MOF aerogels could make the most of their pores and accessible surface areas for higher adsorption capacity and rapid adsorption kinetics of different molecules, in sharp contrast to conventional MOF powders. Thus, this scalable and low-cost production pathway is able to convert MOF powders into a shapeable and flexible form and thereby extend their applications in more broad fields, for example, adapting a conventional filtration setup.

Conjugated polymer systems, including homopolymers, 1 alternating/random copolymers, 2 blends, 3 and block copolymers, 4,5 as semiconductors for electronic and optoelectronic applications are of continuing great interest. 6,7 In general, multicomponent conjugated polymer systems such as blends and block copolymers offer the opportunity to optimize and tailor electronic and optical properties while also having the potential to observe novel phenomena (e.g., energy transfer, charge transfer) not feasible in homopolymers and random/alternating copolymers.5 Compared to blends, 3 block copolymers are of special interest because of their superior self-assembly features and the improved control of the nanoscale domain sizes of their assembled structures. Indeed, the synthesis, self-assembly, and properties of rod-coil block copolymers, having a π-conjugated (rodlike) block and a coillike nonconjugated block, have been extensively studied. 4 Although experimental examples of allconjugated block copolymers have been known since 1996, 5a their synthesis, solution-phase self-assembly, melt-phase selfassembly, and properties remain to be fully investigated. 5,8 Recently, block copolythiophenes with crystalline-amorphous diblock architecture incorporating a crystalline poly(3-hexylthiophene) (P3HT) block were successfully synthesized by quasiliving chain growth polymerization, including poly{3-[2-(2-methoxyethoxy)ethoxy]methylthiophene}, 8b poly[3-(2-ethylhexylthiophene)], 8c or poly(3-phenoxymethylthiophene) 8d as the amorphous segment. The thin-film morphology of these crystalline-amorphous diblock copolythiophenes was shown by atomic force microscopy (AFM) to be microphase-separated into crystalline and amorphous domains. For many electronic and optoelectronic applications such as field-effect transistors and photovoltaic devices, where high carrier mobilities and high absorption coefficients are important, 6,7 amorphous domains are undesirable. We report herein the synthesis and self-assembly of crystalline-crystalline diblock copoly(3-alkylthiophene)s. Two compositions of the new regioregular poly(3-butylthiophene)-b-poly(3-octylthiophene) (P3BT-b-P3OT) were found to self-assemble into crystalline nanowires in solution and shown by wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) to be microphase-separated from the melt phase into two distinct crystalline domains with a lamellar structure.The synthesis of the diblock copoly(3-alkylthiophene)s was carried out by a modified Grignard metathesis method (GRIM), 1b,8 as illustrated in Scheme 1. The P3OT block was first synthesized by polymerization of 2,5-dibromo-3-octylthiophene, followed by the addition of activated 2,5-dibromo-3-butylthiophene monomer solution, giving the diblock copolymer system, poly(3-butylthiophene)-b-poly(3-octylthiophene). Two compositions, denoted BO50 and BO76, were synthesized by using the feed ratios of 2,5-dibromo-3-octylthiophene to 2,5-dibromo-3-butylthiophene of 1:1 and 1:2, respectively. The actual compositions...

Recent advances in bio-nanotechnology have not only rapidly broadened the applications and scope of hybrid nanomaterials in biological fields, but also greatly enriched the examples of ordered materials based on supramolecular self-assembly. Among eminent examples of functional nanostructured materials of undisputed impact in nanotechnology and biological environments, carbon nanomaterials (such as fullerenes, carbon nanotubes and graphene) and amyloid fibrils have attracted great attention because of their unique architectures and exceptional physical properties. Nonetheless, combination of these two classes of nanomaterials into functional hybrids is far from trivial. For example, the presence of carbon nanomaterials can offer either an inhibitory effect or promotion of amyloid fibrillation, depending on the structural architectures of carbon nanomaterials and the starting amyloid proteins/peptides considered. To date, numerous studies have been devoted to evaluating both the biological toxicity of carbon nanomaterials and their use in developing therapies for amyloidosis. At the same time, hybridization of these two classes of nanomaterials offers new possibilities for combining some of their desirable properties into nanocomposites of possible use in electronics, actuators, sensing, biomedicine and structural materials. This review describes recent developments in the hybridization of carbon nanomaterials and amyloid fibrils and discusses the current state of the art on the application of carbon nanomaterial-amyloid fibril hybrids in bio-nanotechnology.

A "bottom up" strategy is proposed to synthesize high aspect ratio hydroxyapatite (and brushite) platelets, and combine them with amyloid fibrils into layered hybrid nanocomposites. Their hierarchical structure, despite the differences from natural bone, confers to the nanocomposites a density and elastic modulus matching those of cancellous bone. Evidence of good adhesion and spreading of human trabecular bone-derived pre-osteoblasts cells on these nanocomposites is provided.

Liquid metal (LM) droplets show the superiority in coalescing into integral liquid conductors applicable in flexible and deformable electronics. However, the large surface tension, oxide shells and poor compatibility with most other materials may prevent spontaneous coalescence of LM droplets and/or hybridisation into composites, unless external interventions (e.g., shear and laser) are applied. Here, we show that biological nanofibrils (NFs; including cellulose, silk fibroin and amyloid) enable evaporation-induced sintering of LM droplets under ambient conditions into conductive coating on diverse substrates and free-standing films. The resultants possess an insulating NFs-rich layer and a conductive LM-rich layer, offering flexibility, high reflectivity, stretchable conductivity, electromagnetic shielding, degradability and rapid actuating behaviours. Thus this sintering approach not only extends fundamental knowledge about sintering LM droplets, but also starts a new scenario of producing flexible coating and free-standing composites with flexibility, conductivity, sustainability and degradability, and applicable in microcircuits, wearable electronics and soft robotics.

Amyloid fibrils and silk fibroin (SF) fibrils are proteinaceous aggregates occurring either naturally or as artificially reconstituted fibrous systems, in which the constituent β-strands are aligned either orthogonally or parallel to the fibril main axis, conferring complementary physical properties. Here, it is shown how the combination of these two classes of protein fibrils with orthogonally oriented β-strands results in composite materials with controllable physical properties at the molecular, mesoscopic, and continuum length scales.

Combination of proteins with other nanomaterials offers a promising strategy to fabricate novel hybrids with original functions in biology, medicine, nanotechnology, and materials science. Under carefully selected experimental conditions, we show that graphene nanosheets are able to direct one-dimensional self-assembly of silk fibroin, forming an unprecedented type of nanohybrids. These silk/graphene hybrids combine physical properties of both constituents and form functional composites with well-ordered hierarchical structures. Due to the facile fabrication process and their tunable nanostructures, the resultant hybrids show promise in applications as diverse as tissue engineering, drug delivery, nanoelectronics, nanomedicine, biosensors, and functional composites.