[en] The combination of nanoscaled materials and biological self-assembly is a key step for the development of novel approaches for biotechnology and bionanoelectronic devices. Here we propose a route to merge these two subsystems and report on the formation of highly concentrated aqueous solutions of silanized silicon nanowires wrapped in a lipid bilayer shell. We developed protocols and investigated the dynamics of lipid films on both planar surfaces and silicon nanowires using fluorescence recovery after photobleaching, demonstrating fully intact and fluid bilayers without the presence of a lipid molecule reservoir. Finally, the experimental setup allowed for in situ observation of spontaneous bilayer formation around the nanowire by lipid diffusion from a vesicle to the nanowire. Such aqueous solutions of lipid coated nanowires are a versatile tool for characterization purposes and are relevant for newly emerging bioinspired electronics and nanosensorics. (paper)

[en] A flexible sensor is presented for electrochemical detection of ascorbic acid in sweat based on single-step modified gold microelectrodes. The modification consists of electrodeposition of alginate membrane with trapped CuO nanoparticles. The electrodes are fabricated at a thin polyimide support and the soft nature of the membrane can withstand mechanical stress beyond requirements for skin monitoring. After characterization of the membrane via optical and scanning electron microscopy and cyclic voltammetry, the oxidative properties of CuO are exploited toward ascorbic acid for amperometric measurement at micromolar levels in neutral buffer and acidic artificial sweat, at ultralow applied potential (− 5 mV vs. Au pseudo-reference electrode). Alternatively, measurement of the horizontal shift of redox peaks by cyclic voltammetry is also possible. Obtaining a limit of detection of 1.97 μM, sensitivity of 0.103 V log (μM)⁻¹ of peak shift, and linear range of 10–150 μM, the effect of possible interfering species present in sweat is minimized, with no observable cross-reaction, thus maintaining a high degree of selectivity despite the absence of enzymes in the fabrication scheme. With a lateral flow approach for sample delivery, repeated measurements show recovery in few seconds, with relative standard deviation of about 20%, which can serve to detect increased loss or absence of vitamin, and yet be improved in future by optimized device designs. This sensor is envisioned as a promising component of wearable devices for e.g. non-invasive monitoring of micronutrient loss through sweat, comprising features of light weight, low cost, and easy fabrication needed for such application.

[en] Highlights: • The composite film of carbon nanotubes and silicon carbide nanowires possessing two different wire-like nanostructures is obtained by the catalyst-assisted method. • The composite film without any functionalization on surface possesses the superhydrophobicity with a high contact angle closing to 160°. • The superhydrophobicity of the self-cleaning composite film is attributed to enhanced water/air inter facial area due to the presence of the silicon carbide nanowires. - Abstract: The composite film of carbon nanotubes and silicon carbide nanowires was synthesized directly on the silicon substrate by the catalyst-assisted method. The carbon nanotubes crimped together decorated with silicon carbide nanowires covering the whole substrate. The appropriate amount of aluminum powders is a crucial factor to achieve the composite film. The composite film exhibited excellent intrinsic superhydrophobicity without any further functionalization. By using the nano/micropillar composite structure model, the presence of silicon carbide nanowires is found to be the key factor that results in the superhydrophobicity of the films. The feasible synthesis of the superhydrophobic coating could have potential application in water-repelling devices, like biochemical sensors and microfluidic systems.

[en] Despite the recent progress in the synthesis of crystalline boronate ester covalent organic frameworks (BECOFs) in powder and thin-film through solvothermal method and on-solid-surface synthesis, respectively, their applications in electronics, remain less explored due to the challenges in thin-film processability and device integration associated with the control of film thickness, layer orientation, stability and crystallinity. Moreover, although the crystalline domain sizes of the powder samples can reach micrometer scale (up to $\approx <!--\; ???\; -->$ 1.5 $\mathrm{\mu <!--\; ??\; -->}$m), the reported thin-film samples have so far rather small crystalline domains up to 100 nm. Here we demonstrate a general and efficient synthesis of crystalline two-dimensional (2D) BECOF films composed of porphyrin macrocycles and phenyl or naphthyl linkers (named as 2D BECOF-PP or 2D BECOF-PN) by employing a surfactant-monolayer-assisted interfacial synthesis (SMAIS) on the water surface. The achieved 2D BECOF-PP is featured as free-standing thin film with large single-crystalline domains up to $\approx <!--\; ???\; -->$ 60 $\mathrm{\mu <!--\; ??\; -->}$m${}^2$ and tunable thickness from 6 to 16 nm. A hybrid memory device composed of 2D BECOF-PP film on silicon nanowire-based field-effect transistor is demonstrated as a bio-inspired system to mimic neuronal synapses, displaying a learning-erasing-forgetting memory process. (© 2020 Wiley‐VCH Verlag GmbH and Co. KGaA, Weinheim)