Bioactive Ion-Confined Ultracapacitive Memristors with Neuromorphic Functions.

The field of bioinspired iontronics, bridging electronic devices and ionic systems, has multiple biological applications. Carbon-based ultracapacitive devices hold promise for controlling bioactive ions via electric double layers due to their high-surface-area and biocompatible porous carbon electrodes. However, the interplay between complex bioactive ions and porous carbons remains unclear due to the variety of structures of bioactive ions present in biological systems. Herein, we investigate the adsorption behavior of a series of bioactive ammonium-based cations with varying alkyl chain lengths in nanoporous carbons. We find that strong physisorption results from the synergistic hydrophobic interaction and electrostatic attraction between porous carbons (with a negative zeta potential) and bioactive cations. Bioactive cations with varying alkyl chain lengths can be irreversibly physically adsorbed and confined within nanoporous carbons resulting in anion enrichment and depletion during electric polarization. This situation, in turn, results in a characteristic memristive behavior in all-carbon capacitive ionic memristor devices. Our findings highlight the relationship between the resistance state of the memristor and ion adsorption mechanisms in all-carbon capacitive devices, which hold potential for future transmitter delivery, biointerfacing, and neuromorphic devices.

Unlocking Four-electron Conversion in Tellurium Cathodes for Advanced Magnesium-based Dual-ion Batteries.

Magnesium (Mg) batteries hold promise as a large-scale energy storage solution, but their progress has been hindered by the lack of high-performance cathodes. Here, we address this challenge by unlocking the reversible four-electron Te0/Te4+ conversion in elemental Te, enabling the demonstration of superior Mg//Te dual-ion batteries. Specifically, the classic magnesium aluminum chloride complex (MACC) electrolyte is tailored by introducing Mg bis(trifluoromethanesulfonyl)imide (Mg(TFSI)2), which initiates the Te0/Te4+ conversion with two distinct charge-storage steps. Te cathode undergoes Te/TeCl4 conversion involving Cl- as charge carriers, during which a tellurium subchloride phase is presented as an intermediate. Significantly, the Te cathode achieves a high specific capacity of 543 mAh gTe -1 and an outstanding energy density of 850 Wh kgTe -1, outperforming most of the previously reported cathodes. Our electrolyte analysis indicates that the addition of Mg(TFSI)2 reduces the overall ion-molecule interaction and mitigates the strength of ion-solvent aggregation within the MACC electrolyte, which implies the facilized Cl- dissociation from the electrolyte. Besides, Mg(TFSI)2 is verified as an essential buffer to mitigate the corrosion and passivation of Mg anodes caused by the consumption of the electrolyte MgCl2 in Mg//Te dual-ion cells. These findings provide crucial insights into the development of advanced Mg-based dual-ion batteries.

General Design Concepts for CAPodes as Ionologic Devices.

Capacitive analogues of semiconductor diodes (CAPodes) present a new avenue for energy-efficient and nature-inspired next-generation computing devices. Here, we disclose the generalized concept for bias-direction-adjustable n- and p-CAPodes based on selective ion sieving. Controllable-unidirectional ion flux is realized by blocking electrolyte ions from entering sub-nanometer pores. The resulting CAPodes exhibit charge-storage characteristics with a high rectification ratio (96.29 %). The enhancement of capacitance is attributed to the high surface area and porosity of an omnisorbing carbon as counter electrode. Furthermore, we demonstrate the use of an integrated device in a logic gate circuit architecture to implement logic operations ('OR', 'AND'). This work demonstrates CAPodes as a generalized concept to achieve p-n and n-p analogue junctions based on selective ion electrosorption, provides a comprehensive understanding and highlights applications of ion-based diodes in ionologic architectures.

Bioactive Ion-Based Switchable Supercapacitors.

Switchable supercapacitors (SCs) enable a reversible electrically-driven uptake/release of bioactive ions by polarizing porous carbon electrodes. Herein we demonstrate the first example of a bioactive ion-based switchable supercapacitor. Based on choline chloride and porous carbons we unravel the mechanism of physisorption vs. electrosorption by nuclear magnetic resonance, Raman, and impedance spectroscopy. Weak physisorption facilitates electrically-driven electrolyte depletion enabling the controllable uptake/release of electrolyte ions. A new 4-terminal device is proposed, with a main capacitor and a detective capacitor for monitoring bioactive ion adsorption in situ. Ion-concentration control in printed choline-based switchable SCs realizes switching down to 8.3 % residual capacitance. The exploration of adsorption mechanisms in printable microdevices will open an avenue of manipulating bioactive ions for the application of drug delivery, neuromodulation, or neuromorphic devices.

Identification of the polyketide synthase PKS7 responsible for the production of lecanoric acid and ethyl lecanorate in Claviceps purpurea.

Claviceps purpurea is a plant pathogenic fungus which is still highly relevant in modern agriculture as it infects grasses such as rye and wheat. The disease caused by the consumption of contaminated grain or flour has been known since the Middle Ages and is termed ergotism. The main cause for the toxicity of this fungus is attributed to the ergot alkaloids. Apart from these alkaloids and the ergochromes known as ergot pigments, the secondary metabolism of C. purpurea is not well investigated. This study demonstrated the function of the polyketide synthase PKS7 in C. purpurea by determining the effect of its overexpression on metabolite profiles. For the first time, the depsides lecanoric acid, ethyl lecanorate, gerfelin, and C10-deoxy gerfelin were discovered as secondary metabolites of C. purpurea. Additionally, to estimate the contribution of isolated secondary metabolites to the toxic effects of C. purpurea, lecanoric acid, ethyl lecanorate, and orsellinic acid were tested on HepG2 and CCF-STTG1 cell lines. This study provides the first report on the function of C. purpurea PKS7 responsible for the production of depsides, among which lecanoric acid and ethyl lecanorate were identified as main secondary metabolites.