MXene/polymer dot-decorated flexible sensor for cancer cell-responsive hydrogel with tunable elastic modulus, porosity, and conductivity.

This study reports a facile strategy for cancer cell modulated mechanically and electronically tunable hydrogel based on MXene-immobilized hyaluronic acid polymer dot (M-PD). Elevated levels of reactive oxygen species (ROS), such as HO in cancer cells cleave MXene owing to the oxygen-titanium affinity of TiCT, altering the physico-mechanical, electrochemical, and fluorescence (FL) properties of the sensor. The HO-induced cleavage of M-PD in the hydrogel causes the quenched FL intensity by the Forster resonance energy transfer effect (FRET) to recover, alongside an increase in pore size, influencing shifts in hydrogen bonding and inducing viscoelastic changes in the flexible sensor.

Electrochemical and fluorescent dual-mode sensor of acetylcholinesterase activity and inhibition based on MnO@PD-coated surface.

We developed an electrochemical and fluorescent dual-mode sensor for assessing acetylcholinesterase (AChE) activity and inhibition by taking advantage of the high redox sensitivity of surface-coated mesoporous MnO@polymer dot (MnO@PD) towards AChE. The following phenomena constitute the basis of the detection mechanism: fluorescence resonance energy transfer (FRET) effect between MnO and PD; catalytic hydrolysis of acetylthiocholine (ATCh) to thiocholine (TCh) by AChE expressed by PC-12 cells, inducing fluorescence restoration and change in the conductivity of the system due to MnO decomposition; the presence of the inhibitor neostigmine preventing the conversion of ATCh to TCh. The surface-coated biosensor presents both fluorescence-based and electrochemical approaches for effectively monitoring AChE activity and inhibition.

N,S-co-doped FeCo Nanoparticles Supported on Porous Carbon Nanofibers as Efficient and Durable Oxygen Reduction Catalysts.

Finding high-performance, low-cost, efficient catalysts for oxygen reduction reactions (ORR) is essential for sustainable energy conversion systems. Herein, highly efficient and durable iron (Fe) and cobalt (Co)-supported nitrogen (N) and sulfur (S) co-doped three-dimensional carbon nanofibers (FeCo-N, S@CNFs) were synthesized via electrospinning followed by carbonization. The as-prepared FeCo-N,S@CNFs served as efficient ORR catalysts in alkaline 0.

Hollow Porous N and Co Dual-Doped Silicon@Carbon Nanocube Derived by ZnCo-Bimetallic Metal-Organic Framework toward Advanced Lithium-Ion Battery Anodes.

Silicon (Si) has been recognized as a promising alternative to graphite anode materials for advanced lithium-ion batteries (LIBs) owing to its superior theoretical capacity and low discharge voltage. However, Si-based anodes undergo structural pulverization during cycling due to the large volume expansion (ca. 300-400%) and continuous formation of an unstable solid electrolyte interphase (SEI), resulting in fast capacity fading.

Ultrahigh Energy Density and Long-Life Cyclic Stability of Surface-Treated Aluminum-Ion Supercapacitors.

In this study, aluminum-graphene supercapacitors (denoted as aluminum-ion supercapacitors; ASCs), consisting of a battery-type aluminum anode, a capacitor-type graphene cathode, and ionic liquid 1-ethyl-3-methylimidazolium chloride (EMImCl) and aluminum chloride (AlCl) electrolyte, were prepared. This study primarily aimed to investigate the enhanced electrochemical performance of ASCs arising from changes in the surface oxide layer and morphology via electrochemical surface treatments, including electropolishing and electrodeposition of aluminum anodes. The ASC devices based on an electrodeposited anode at a current density of 3 A g exhibited a high specific capacity of 211 F g compared to that of the electropolished anode (∼186 F g); these were 20 and 5.

Robust Co alloy design for Co interconnects using a self-forming barrier layer.

With recent rapid increases in Cu resistivity, RC delay has become an important issue again. Co, which has a low electron mean free path, is being studied as beyond Cu metal and is expected to minimize this increase in resistivity. However, extrinsic time-dependent dielectric breakdown has been reported for Co interconnects.

Thermodynamically driven self-formation of Ag nanoparticles in Zn-embedded carbon nanofibers for efficient electrochemical CO reduction.

The electrochemical CO reduction reaction (CORR), which converts CO into value-added feedstocks and renewable fuels, has been increasingly studied as a next-generation energy and environmental solution. Here, we report that single-atom metal sites distributed around active materials can enhance the CORR performance by controlling the Lewis acidity-based local CO concentration. By utilizing the oxidation Gibbs free energy difference between silver (Ag), zinc (Zn), and carbon (C), we can produce Ag nanoparticle-embedded carbon nanofibers (CNFs) where Zn is atomically dispersed by a one-pot, self-forming thermal calcination process.

High-Defect-Density Graphite for Superior-Performance Aluminum-Ion Batteries with Ultra-Fast Charging and Stable Long Life.

Rechargeable aluminum-ion batteries (AIBs) are a new generation of low-cost and large-scale electrical energy storage systems. However, AIBs suffer from a lack of reliable cathode materials with insufficient intercalation sites, poor ion-conducting channels, and poor diffusion dynamics of large chloroaluminate anions (AlCl and AlCl). To address these issues, surface-modified graphitic carbon materials [i.

Electrochemical oxidation of boron-doped nickel-iron layered double hydroxide for facile charge transfer in oxygen evolution electrocatalysts.

The oxygen evolution reaction (OER) is the key reaction in water splitting systems, but compared with the hydrogen evolution reaction (HER), the OER exhibits slow reaction kinetics. In this work, boron doping into nickel-iron layered double hydroxide (NiFe LDH) was evaluated for the enhancement of OER electrocatalytic activity. To fabricate boron-doped NiFe LDH (B:NiFe LDH), gaseous boronization, a gas-solid reaction between boron gas and NiFe LDH, was conducted at a relatively low temperature.

Fast charging with high capacity for aluminum rechargeable batteries using organic additive in an ionic liquid electrolyte.

Aluminum-ion batteries have many advantages such as the natural abundance of aluminum, high theoretical capacity, and low cost. However, the ionic liquid commonly used as the electrolyte for aluminum-ion batteries has high viscosity, which hinders the migration of charge carriers. In this study, we used various organic solvents as additives for the ionic liquid electrolyte and investigated their effect on the battery performance.

NIR-vis-Induced pH-Sensitive TiO Immobilized Carbon Dot for Controllable Membrane-Nuclei Targeting and Photothermal Therapy of Cancer Cells.

This study investigated a selective and sensitive theragnosis system for the specific targeting of the membrane and nuclei based on visible-light and pH-responsive TiO-integrated cross-linked carbon dot (C-CD/TiO) for tumor detection and controllable photothermal therapy. The cross-linking system was formed by boronate ester linkages between the TiO-immobilized Dopa-decyl (D-CD) and zwitterionic-formed CD (Z-CD) for nuclear targeting, which showed fluorescence "off" at physiological pH. The fluorescence recovered to the "on" state in acidic cancer cells owing to cleavages of the boronate ester bonds, resulting in the disruption of the Förster resonance energy transfer that generated different CDs useful for tumor-selective biosensors and therapy.

Nitrogen-doped TiO(B) nanobelts enabling enhancement of electronic conductivity and efficiency of lithium-ion storage.

To enhance the intrinsic electrical conductivities of TiO(B) nanobelts, nitrogen(N)-doped TiO(B) nanobelts (N-TNB) were prepared in this study by a facile and cost-effective hydrothermal method using urea as the nitrogen source with TiO (P25) nanoparticles. x-ray photoelectron spectroscopy confirmed that the N-atoms preferentially occupied up to ∼0.516 atom% in the interstitial sites of the N-TNB and the maximum concentration of substituted-N bonds in the N-TNB was ∼0.

Diselenide-Bridged Carbon-Dot-Mediated Self-Healing, Conductive, and Adhesive Wireless Hydrogel Sensors for Label-Free Breast Cancer Detection.

Recently, a great deal of research has focused on the study of self-healing hydrogels possessing electronic conductivity due to their wide applicability for use in biosensors, bioelectronics, and energy storage. The low solubility, poor biocompatibility, and lack of effective stimuli-responsive properties of their sp carbon-rich hybrid organic polymers, however, have proven challenging for their use in electroconductive self-healing hydrogel fabrication. In this study, we developed stimuli-responsive electrochemical wireless hydrogel biosensors using ureidopyriminone-conjugated gelatin (Gel-UPy) hydrogels that incorporate diselenide-containing carbon dots (dsCD) for cancer detection.

One-dimensional hierarchical nanostructures of NiCoO, NiCoS and NiCoSe with superior electrocatalytic activities toward efficient oxygen evolution reaction.

Oxygen evolution reaction (OER), a sluggish multistep process in electrochemical water splitting, is still a challenging issue to achieve with cheap, earth-abundant non-precious and non-polluting materials. In this work, three different electrocatalysts, specifically NiCoO, NiCo S, and NiCo Se synthesized by simple hydrothermal process, show excellent OER activity. This report not only projects OER performances but also demonstrates a modified method for the transformation of NiCoO to NiCo S and NiCo Se via sulfidation and selenization reactions.

Metal-organic Framework-driven Porous Cobalt Disulfide Nanoparticles Fabricated by Gaseous Sulfurization as Bifunctional Electrocatalysts for Overall Water Splitting.

Both high activity and mass production potential are important for bifunctional electrocatalysts for overall water splitting. Catalytic activity enhancement was demonstrated through the formation of CoS nanoparticles with mono-phase and extremely porous structures. To fabricate porous structures at the nanometer scale, Co-based metal-organic frameworks (MOFs), namely a cobalt Prussian blue analogue (Co-PBA, Co[Co(CN)]), was used as a porous template for the CoS.

Reduction-Triggered Paclitaxel Release Nano-Hybrid System Based on Core-Crosslinked Polymer Dots with a pH-Responsive Shell-Cleavable Colorimetric Biosensor.

Herein, we describe the fabrication and characterization of carbonized disulfide core-crosslinked polymer dots with pH-cleavable colorimetric nanosensors, based on diol dye-conjugated fluorescent polymer dots (L-PD), for reduction-triggered paclitaxel (PTX) release during fluorescence imaging-guided chemotherapy of tumors. L-PD were loaded with PTX (PTX loaded L-PD), via π-π stackings or hydrophobic interactions, for selective theragnosis by enhanced release of PTX after the cleavage of disulfide bonds by high concentration of glutathione (GSH) in a tumor. The nano-hybrid system showed fluorescence quenching behavior with less than 2% of PTX released under physiological conditions.

Nb-doped TiO support with enhanced durability as a cathode for polymer electrolyte membrane fuel cells.

Stability is one of the key requirements of electrocatalyst support materials for polymer electrolyte membrane fuel cells. To develop a highly stable Pt catalyst support material, in this work, we have synthesized Nb-doped TiO electrocatalyst supports. The amount of Nb dopant is measured using inductively coupled plasma mass spectrometry, while the characteristics of the as-prepared Nb-doped TiO supports are analyzed by transmission electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy.

RGO-Coated TiO Microcones for High-Rate Lithium-Ion Batteries.

Reduced graphene oxide (RGO)-coated TiO microcones have been synthesized via simple anodization and cyclic voltammetry for use in lithium-ion batteries (LIBs). Microcones had a perpendicularly oriented hollow core, an anatase structure, and a high surface area, allowing higher capacity than other nanosized TiO structures. TiO has low electrical conductivity, leading to the limitation of fast charging and high capacity; however, this was improved by the application of an RGO coating in this work.

Thermally Stable Amorphous Oxide-based Schottky Diodes through Oxygen Vacancy Control at Metal/Oxide Interfaces.

Amorphous oxide semiconductor (AOS)-based Schottky diodes have been utilized for selectors in crossbar array memories to improve cell-to-cell uniformity with a low-temperature process. However, thermal instability at interfaces between the AOSs and metal electrodes can be a critical issue for the implementation of reliable Schottky diodes. Under post-fabrication annealing, an excessive redox reaction at the ohmic interface can affect the bulk region of the AOSs, inducing an electrical breakdown of the device.

Zwitterionic carbon dot-encapsulating pH-responsive mesoporous silica nanoparticles for NIR light-triggered photothermal therapy through pH-controllable release.

Here, we designed a pH-responsive Indocyanine Green (ICG)-loaded zwitterion fluorescent carbon dot (CD)-encapsulating mesoporous silica nanoparticle (MSN) for pH-tunable image-guided photothermal therapy. ICG was loaded into MSN(CD) via hydrophobic and electrostatic interactions between zwitterionic CDs and ICG to achieve a controlled photothermal temperature with a fluorescent "off/on" system. The porosity of the MSNs was altered after ICG loading because of intermolecular interactions between the CDs and ICG inside the MSN shell and core, which blocked the MSN pore.

Binder-free SnO-TiO composite anode with high durability for lithium-ion batteries.

A SnO-TiO electrode was prepared anodization and subsequent anodic potential shock for a binder-free anode for lithium-ion battery applications. Perpendicularly oriented TiO microcones are formed by anodization; SnO, originating in a NaSnO precursor, is then deposited in the valleys between the microcones and in their hollow cores by anodic potential shock. This sequence is confirmed by SEM and TEM analyses and EDS element mapping.

In situ durability of various carbon supports against carbon corrosion during fuel starvation in a PEM fuel cell cathode.

In this study, the degradation of different cathode carbon supports is investigated in proton exchange membrane fuel cells (PEMFCs). A platinum catalyst is synthesized using various carbon supports, such as Vulcan XC-72, graphite nanopowder and carbon nanotube, which are evaluated based on the fabrication of membrane electrode assemblies. During the startup and shutdown of PEMFCs, the individual electrode potential can be measured in situ using a dynamic hydrogen electrode.

Fast-Charging and High Volumetric Capacity Anode Based on Co O /CuO@TiO Composites for Lithium-Ion Batteries.

This paper presents an investigation of anodic TiO nanotube arrays (TNAs), with a Co O /CuO coating, for lithium-ion batteries (LIBs). The coated TNAs are investigated using various analytical techniques, with the results clearly suggesting that the molar ratio of Co O /CuO in the TiO nanotubes substantially influences its battery performance. In particular, a cobalt/copper molar ratio of 2:1 on the TNAs (Co Cu @TNAs) features the best LIBs anode performance, exhibiting high reversible capacity and enhanced cycling stability.

Redox-responsive FRET-based polymer dot with BODIPY for fluorescence imaging-guided chemotherapy of tumor.

Redox-responsive polymer dot (PD) were synthesized from disulfide cross-linked polymers in a carbonized process to allow quenching effects by loading of boron-dipyrromethene (BODIPY) onto the matrix. The disulfide linkage facilitated degradation of the PD system by intracellular glutathione (GSH), leading to fluorescence recovery by BODIPY and intracellular drug release. The paclitaxel release profile showed that approximately 100% of the drug escaped from the matrix in response to 10 mM GSH, whereas less than 10% was released in the absence of GSH.