Oxidative photocatalysis on membranes triggers non-canonical pyroptosis.

Intracellular membranes composing organelles of eukaryotes include membrane proteins playing crucial roles in physiological functions. However, a comprehensive understanding of the cellular responses triggered by intracellular membrane-focused oxidative stress remains elusive. Herein, we report an amphiphilic photocatalyst localised in intracellular membranes to damage membrane proteins oxidatively, resulting in non-canonical pyroptosis. Our developed photocatalysis generates hydroxyl radicals and hydrogen peroxides via water oxidation, which is accelerated under hypoxia. Single-molecule magnetic tweezers reveal that photocatalysis-induced oxidation markedly destabilised membrane protein folding. In cell environment, label-free quantification reveals that oxidative damage occurs primarily in membrane proteins related to protein quality control, thereby aggravating mitochondrial and endoplasmic reticulum stress and inducing lytic cell death. Notably, the photocatalysis activates non-canonical inflammasome caspases, resulting in gasdermin D cleavage to its pore-forming fragment and subsequent pyroptosis. These findings suggest that the oxidation of intracellular membrane proteins triggers non-canonical pyroptosis.

Influence of the Lithium-Ion Concentration in Electrolytes on the Performance of Dye-Sensitized Photorechargeable Batteries.

Dye-sensitized photorechargeable batteries (DSPBs) have recently gained attention for realizing energy recycling systems under dim light conditions. However, their performance under high storage efficiency (i.e., the capacity charged within a limited time) for practical application remains to be evaluated. Herein, we varied the lithium (Li)-ion concentration, which plays a dual role as energy charging and storage components, to obtain the optimized energy density of DSPBs. Electrochemical studies showed that the Li-ion concentration strongly affected the resistance characteristics of DSPBs. In particular, increasing the Li-ion concentration improved the output capacity and decreased the output voltage. Consequently, the energy density of the finely optimized DSPB improved from 8.73 to 12.64 mWh/cm3 when irradiated by a 1000-lx indoor light-emitting-diode lamp. These findings on the effects of Li-ion concentrations in electrolytes on the performance of DSPBs represent a step forward in realizing the practical application of DSPBs.

Singlet Oxygen Generation from Polyaminoglycerol by Spin-Flip-Based Electron Transfer.

Reactive oxygen species have drawn attention owing to their strong oxidation ability. In particular, the singlet oxygen (1O2) produced by energy transfer is the predominant species for controlling oxidation reactions efficiently. However, conventional 1O2 generators, which rely on enhanced energy transfer, frequently suffer from poor solubility, low stability, and low biocompatibility. Herein, we introduce a hyperbranched aliphatic polyaminoglycerol (hPAG) as a 1O2 generator, which relies on spin-flip-based electron transfer. The coexistence of a lone pair electron on the nitrogen atom and a hydrogen-bonding donor (the protonated form of nitrogen and hydroxyl group) affords proximity between hPAG and O2. Subsequent direct electron transfer after photo-irradiation induces hPAG•+-O2 •- formation, and the following spin-flip process generates 1O2. The spin-flip-based electron transfer pathway is analyzed by a series of photophysical, electrochemical, and computational studies. The 1O2 generator, hPAG, is successfully employed in photodynamic therapy and as an antimicrobial reagent.

Sono-Cavitation and Nebulization-Based Synthesis of Conjugated Microporous Polymers for Energy Storage Applications.

Conjugated microporous polymers (CMPs) are promising energy storage materials owing to their rigid and cross-linked microporous structures. However, the fabrication of nano- and microstructured CMP films for practical applications is currently limited by processing challenges. Herein, we report that combined sono-cavitation and nebulization synthesis (SNS) is an effective method for the synthesis of CMP films from a monomer precursor solution. Using the SNS, the scalable fabrication of microporous and redox-active CMP films can be achieved via the oxidative C-C coupling polymerization of the monomer precursor. Intriguingly, the ultrasonic frequency used during SNS strongly affects the synthesis of the CMP films, resulting in an approximately 30% improvement in reaction yields and ca. 1.3-1.7-times enhanced surface areas (336-542 m2/g) at a high ultrasonic frequency of 180 kHz compared to those at 120 kHz. Furthermore, we prepare highly conductive, three-dimensional porous electrodes [CMP/carbon nanotube (CNT)] by a layer-by-layer sequential deposition of CMP films and CNTs via SNS. Finally, an asymmetric supercapacitor comprising the CMP/CNT cathode and carbon anode shows a high specific capacitance of 477 F/g at 1 A/g with a wide working potential window (0-1.4 V) and robust cycling stability, exhibiting 94.4% retention after 10,000 cycles.

Dual-Functional Electrolyte Additives toward Long-Cycling Lithium-Ion Batteries: Ecofriendly Designed Carbonate Derivatives.

Long-term stability of the solid electrolyte interphase (SEI) and cathode-electrolyte interface (CEI) layers formed on anodes and cathodes is imperative to mitigate the interfacial degradation of electrodes and enhance the cycle life of lithium-ion batteries (LIBs). However, the SEI on the anode and CEI on the cathode are vulnerable to the reactive species of PF5 and HF produced by the decomposition and hydrolysis of the conventional LiPF6 electrolyte in a battery inevitably containing a trace amount of water. Here, we report a new class of cyclic carbonate-based electrolyte additives to preserve the integrity of SEI and CEI in LIBs. This new class of additives is designed and synthesized by an ecofriendly approach that involves fixing CO2 with functional epoxides bearing various reactive side chains. It was found that the cyclic carbonates of 3-(1-ethoxyethoxy)-1,2-propylene carbonate and 3-trimethoxysilylpropyloxy-1,2-propylene carbonate, possessing high capability for the stabilization of Lewis-acidic PF5, exhibit a capacity retention of 79.0% after 1000 cycles, which is superior to that of the pristine electrolyte of 54.7%. Moreover, TMSPC has HF-scavenging capability, which, along with PF5 stabilization, results in enhanced rate capability of commercial LiNi0.6Mn0.2Co0.2O2 (NCM622)/graphite full cells, posing a significant potential for high-energy-density LIBs with long cycle stability.

Molecular Engineering for Enhanced Charge Transfer in Thin-Film Photoanode.

We developed three types of dithieno[3,2-b;2',3'-d]thiophene (DTT)-based organic sensitizers for high-performance thin photoactive TiO2 films and investigated the simple but powerful molecular engineering of different types of bonding between the triarylamine electron donor and the conjugated DTT π-bridge by the introduction of single, double, and triple bonds. As a result, with only 1.3 µm transparent and 2.5-µm TiO2 scattering layers, the triple-bond sensitizer (T-DAHTDTT) shows the highest power conversion efficiency (η = 8.4%; VOC = 0.73 V, JSC = 15.4 mA·cm-2, and FF = 0.75) in an iodine electrolyte system under one solar illumination (AM 1.5, 1000 W·m-2), followed by the single-bond sensitizer (S-DAHTDTT) (η = 7.6%) and the double-bond sensitizer (D-DAHTDTT) (η = 6.4%). We suggest that the superior performance of T-DAHTDTT comes from enhanced intramolecular charge transfer (ICT) induced by the triple bond. Consequently, T-DAHTDTT exhibits the most active photoelectron injection and charge transport on a TiO2 film during operation, which leads to the highest photocurrent density among the systems studied. We analyzed these correlations mainly in terms of charge injection efficiency, level of photocharge storage, and charge-transport kinetics. This study suggests that the molecular engineering of a triple bond between the electron donor and the π-bridge of a sensitizer increases the performance of dye-sensitized solar cell (DSC) with a thin photoactive film by enhancing not only JSC through improved ICT but also VOC through the evenly distributed sensitizer surface coverage.