Charge Selectivity Research Articles

On Diffusiophoresis of a Soft Particle with a Hydrophobic Inner Core: A Semianalytical Study.

The current study deals with a theoretical analysis of diffusiophoresis of a soft particle, consisting of a hydrophobic charged rigid core coated with an ion- and fluid-penetrable charged polymer layer suspending in an electrolyte medium in reaction to an applied concentration gradient. The inner core's hydrophobicity is assumed to be characterized by a surface-charge-dependent slip length parameter. Based on a weak particle charge consideration, the governing equations describing the flow phenomena are solved theoretically to deduce a semianalytic general diffusiophoretic mobility expression applied to an arbitrary Debye layer thickness. A closed-form analytic solution is also obtained, which applies to a thin Debye length and low permeable porous layer. The impact of the charge-dependent wettability of the rigid core on the particle's diffusiophoretic motion is analyzed. We found that the inner core's hydrophobicity profoundly influences the particle mobility at a thicker Debye layer with a constant surface charge density when the chemiphoresis and electrophoresis components assist each other. At a fixed ζ-potential, the effect of the hydrophobic core is substantial for a thinner Debye length. In addition, with a critical selection of core and polymer layer charges, mobility reversal is demonstrated by modulating the salt concentration and slip length parameters.

An Activity Network Design and Charging Facility Planning Model Considering the Influence of Uncertain Activities in a Game Framework

In the planning of public charging facilities and the charging activity network of users, there is a decision-making conflict among three stakeholders: the government, charging station enterprises, and electric vehicle users. Previous studies have described the tripartite game relationship in a relatively simplistic manner, and when designing charging facility planning schemes, they did not consider scenarios where users’ choice preferences undergo continuous random changes. In order to reduce the impacts of queuing phenomenon and resource idleness on the three participants, we introduce a bilateral matching algorithm combined with the dynamic Huff model as a strategy for EV charging selection in the passenger flow problem based on the three-dimensional activity network of time–space–energy of users. Meanwhile, the Dirichlet distribution is utilized to control the selection preferences on the user side, constructing uncertain scenarios for the choice of user charging activities. In this study, we establish a bilevel programming model that takes into account the uncertainty in social responsibility and user charging selection behavior. Solutions for the activity network and facility planning schemes can be derived based on the collaborative relationships among the three parties. The model employs a robust optimization method to collaboratively design the charging activity network and facility planning scheme. For this mixed-integer nonlinear multi-objective multi-constraint optimization problem, the model is solved by the NSGA-II algorithm, and the optimal compromise scheme is determined by using the EWM-TOPSIS comprehensive evaluation method for the Pareto solution set. Finally, the efficacy of the model and the solution algorithm is illustrated by a simulation example in a real urban space.

Mechanistic Insights Into Redox Damage of the Podocyte in Hypertension.

Podocytes are specialized cells within the glomerular filtration barrier, which are crucial for maintaining glomerular structural integrity and convective ultrafiltration. Podocytes exhibit a unique arborized morphology with foot processes interfacing by slit diaphragms, ladder-like, multimolecular sieves, which provide size and charge selectivity for ultrafiltration and transmembrane signaling. Podocyte dysfunction, resulting from oxidative stress, dysregulated prosurvival signaling, or structural damage, can drive the development of proteinuria and glomerulosclerosis in hypertensive nephropathy. Functionally, podocyte injury leads to actin cytoskeleton rearrangements, foot process effacement, dysregulated slit diaphragm protein expression, and impaired ultrafiltration. Notably, the renin-angiotensin system plays a pivotal role in podocyte function, with beneficial AT2R (angiotensin receptor 2)-mediated nitric oxide (NO) signaling to counteract AT1R (angiotensin receptor 1)-driven calcium (Ca2+) influx and oxidative stress. Disruption of this balance contributes significantly to podocyte dysfunction and drives albuminuria, a marker of kidney damage and overall disease progression. Oxidative stress can also lead to sustained ion channel-mediated Ca2+ influx and precipitate cytoskeletal disorganization. The complex interplay between GPCR (G-protein coupled receptor) signaling, ion channel activation, and redox injury pathways underscores the need for additional research aimed at identifying targeted therapies to protect podocytes and preserve glomerular function. Earlier detection of albuminuria and podocyte injury through routine noninvasive diagnostics will also be critical in populations at the highest risk for the development of hypertensive kidney disease. In this review, we highlight the established mechanisms of oxidative stress-mediated podocyte damage in proteinuric kidney diseases, with an emphasis on a hypertensive renal injury. We will also consider emerging therapies that have the potential to selectively protect podocytes from redox-related injury.

Charge Carrier Dynamics of SnO2 Electron‐Transporting Layers in Perovskite Solar Cells

Perovskite solar cells (PSCs) have demonstrated remarkable increase in their photovoltaic efficiencies over the past several years. Charge carrier properties including charge selectivity, extraction, and transport play key roles in device performances. Therefore, a comprehensive insight into the charge carrier dynamics and mobility within the bulk materials and at the interface is of great importance for the future development of this cutting‐edge technology. This review discusses the recent advances that have been made in SnO2 electron‐transporting layers and their limitations, followed by outlining the key development of novel strategies in improving SnO2 films through surface defect engineering, interface modification, and doping approaches. In addition, the recent developments are highlighted for identifying the origin of defect and trap center, and promoting SnO2 electron extraction and transporting capacity in PSCs. Importantly, the novel approaches are also discussed for studying photogenerated charge carrier dynamics of the devices. In conclusion, the own prospectives and outlooks are presented for the development of SnO2‐based PSCs, with a particular focus on addressing current difficulties in SnO2 and providing in‐depth understanding on the relationships between materials and devices.

Improving the operating performance of organic solar cells through a novel cathode interface layer

In the classical system of organic PSCs (PTB7-Th: PC71BM), the presence of a cathode interface layer has the function of improving the device performance by lowering the interfacial barrier between the active layer and the electrode, increasing the charge selectivity, regulating the morphology of the active layer, and regulating the absorption of sunlight by the active layer. Therefore, a novel alcohol-soluble electron transport material is synthesized in this paper, which can cause a more prominent self-doping effect by enhancing intramolecular conjugation, and the results show that in terms of exciton dissociation and recombination, it is found that bimolecular recombination and trap-assisted recombination are obviously inhibited, so that the battery using this interface obtains more than 69% of the fill factor (FF) and has a superior energy conversion efficiency (PCE).

Robust Covalent Organic Frameworks for Photosynthesis of H2O2: Advancements, Challenges and Strategies.

Since 2020, covalent organic frameworks (COFs) are emerging as robust catalysts for the photosynthesis of hydrogen peroxide (H2O2), benefiting from their distinct advantages. However, the current efficiency of H2O2 production and solar-to-chemical energy conversion efficiency (SCC) remain suboptimal due to various constraints in the reaction mechanism. Therefore, there is an imperative to propose efficiency improvement strategies to accelerate the development of this reaction system. This comprehensive review delineates recent advances, challenges, and strategies in utilizing COFs for photocatalytic H2O2 production. It explores the fundamentals and challenges (e.g., oxygen (O2) mass transfer rate, O2 adsorption capacity, response to sunlight, electron-hole separation efficiency, charge transfer efficiency, selectivity, and H2O2 desorption) associated with this process, as well as the advantages, applications, classification, and preparation strategies of COFs for this purpose. Various strategies to enhance the performance of COFs in H2O2 production are highlighted. The review aims to stimulate further advancements in utilizing COFs for photocatalytic H2O2 production and discusses potential prospects, challenges, and application areas in this field.

Impact of biochemical properties on the gelation of EPS extracted from aerobic granules

Extracellular Polymeric Substances (EPS) extracted from aerobic granular sludge are a promising source of gel-forming biopolymers. Gaining insights on the charge distribution of these polymers was performed through a fractionation using anionic chromatography. A gelling factor (GF) based on the apparent gel volume and the reactivity of polymers to calcium was attributed to each eluted fraction. The GF values of the eluted anionic EPS correlated with their negative charge. A GF of 0.04 ± 0.03 is measured for molecules eluted at NaCl 0.25 M and a GF of 0.32 ± 0.02 for the molecules eluted at NaCl 0.75 M. However, upon reaching a very high negative charge (elution at NaCl 1 M), the gelation capacity decreases. The size distribution of gelling molecules was analyzed by Size Exclusion Chromatography. High Molecular Weight (MW) molecules are predominantly involved in gelation (between 65 % and 100 % of the high molecular weight fraction from each sample) while low MW molecules participation is relatively limited (lower than 40 % of the low molecular weight fraction from each sample). Moreover, infra-red spectroscopy analysis of the molecules before and after calcium addition showed that mostly proteins and polysaccharides contribute to the hydrogel formation. Colorimetric methods showed that around 60 % of the uronic acids present in the samples could form hydrogels whereas proteins’ participation varied between 0 % and 100 % depending on the fraction.Thus, modulating EPS extraction and purification methods to ensure the preservation of their molecular weight and the selection of appropriate negative charge could be a strategy for EPS valorization.

Interfacial Super‐Assembly of Vacancy Engineered Ultrathin‐Nanosheets Toward Nanochannels for Smart Ion Transport and Salinity Gradient Power Conversion

AbstractIon‐selective nanochannel membranes assembled from two‐dimensional (2D) nanosheets hold immense promise for power conversion using salinity gradient. However, they face challenges stemming from insufficient surface charge density, which impairs both permselectivity and durability. Herein, we present a novel vacancy‐engineered, oxygen‐deficient NiCo layered double hydroxide (NiCoLDH)/cellulose nanofibers‐wrapped carbon nanotubes (VOLDH/CNF‐CNT) composite membrane. This membrane, featuring abundant angstrom‐scale, cation‐selective nanochannels, is designed and fabricated through a synergistic combination of vacancy engineering and interfacial super‐assembly. The composite membrane shows interlayer free‐spacing of ~3.62 Å, which validates the membrane size exclusion selectivity. This strategy, validated by DFT calculations and experimental data, improves hydrophilicity and surface charge density, leading to the strong interaction with K+ ions to benefit the low ion transport resistance and exceptional charge selectivity. When employed in an artificial river water|seawater salinity gradient power generator, it delivers a high‐power density of 5.35 W/m2 with long‐term durability (20,000s), which is almost 400 % higher than that of the pristine NiCoLDH membrane. Furthermore, it displays both pH‐ and temperature‐sensitive ion transport behavior, offering additional opportunities for optimization. This work establishes a basis for high‐performance salinity gradient power conversion and underscores the potential of vacancy engineering and super‐assembly in customizing 2D nanomaterials for diverse advanced nanofluidic energy devices.

Interfacial Super-Assembly of Vacancy Engineered Ultrathin-Nanosheets Toward Nanochannels for Smart Ion Transport and Salinity Gradient Power Conversion.

Ion-selective nanochannel membranes assembled from two-dimensional (2D) nanosheets hold immense promise for power conversion using salinity gradient. However, they face challenges stemming from insufficient surface charge density, which impairs both permselectivity and durability. Herein, we present a novel vacancy-engineered, oxygen-deficient NiCo layered double hydroxide (NiCoLDH)/cellulose nanofibers-wrapped carbon nanotubes (VOLDH/CNF-CNT) composite membrane. This membrane, featuring abundant angstrom-scale, cation-selective nanochannels, is designed and fabricated through a synergistic combination of vacancy engineering and interfacial super-assembly. The composite membrane shows interlayer free-spacing of ~3.62 Å, which validates the membrane size exclusion selectivity. This strategy, validated by DFT calculations and experimental data, improves hydrophilicity and surface charge density, leading to the strong interaction with K+ ions to benefit the low ion transport resistance and exceptional charge selectivity. When employed in an artificial river water|seawater salinity gradient power generator, it delivers a high-power density of 5.35 W/m2 with long-term durability (20,000s), which is almost 400 % higher than that of the pristine NiCoLDH membrane. Furthermore, it displays both pH- and temperature-sensitive ion transport behavior, offering additional opportunities for optimization. This work establishes a basis for high-performance salinity gradient power conversion and underscores the potential of vacancy engineering and super-assembly in customizing 2D nanomaterials for diverse advanced nanofluidic energy devices.

Normal and Dysregulated Sphingolipid Metabolism: Contributions to Podocyte Injury and Beyond.

Podocyte health is vital for maintaining proper glomerular filtration in the kidney. Interdigitating foot processes from podocytes form slit diaphragms which regulate the filtration of molecules through size and charge selectivity. The abundance of lipid rafts, which are ordered membrane domains rich in cholesterol and sphingolipids, near the slit diaphragm highlights the importance of lipid metabolism in podocyte health. Emerging research shows the importance of sphingolipid metabolism to podocyte health through structural and signaling roles. Dysregulation in sphingolipid metabolism has been shown to cause podocyte injury and drive glomerular disease progression. In this review, we discuss the structure and metabolism of sphingolipids, as well as their role in proper podocyte function and how alterations in sphingolipid metabolism contributes to podocyte injury and drives glomerular disease progression.

Highly Sensitive Diethylamine Detection at Room Temperature Using g-C3N4 Nanosheets Decorated with CuO Hollow Polyhedral Structures.

Chemiresistive-based metal oxide semiconductor (MOS) gas sensors are widely used in gas sensing due to their advantageous properties. Graphitic carbon nitride (g-C3N4) and metal oxide heterostructure materials can improve charge transport properties, selectivity, and sensitivity in MOS gas sensor materials. Herein, for the first time, CuO hollow polyhedral structures (HPSs) were synthesized via a hydrothermal technique and annealed at different temperatures, with the 400 °C annealed (CuO-400 HPSs) demonstrating remarkable sensing capabilities for diethylamine (DEA) gas at room temperature (RT). The x-g-C3N4 nanosheets were decorated with CuO HPSs in varying amounts (x = 0.8, 1.8, 2.1, and 3.1 wt %) and then annealed at 400 °C for x-g-C3N4-CuO-400 hollow polyhedral heterostructures (HPHSs). Indeed, among the synthesized samples, the 1.8%-g-C3N4-CuO-400 HPHSs have a higher sensitivity to DEA (resistance change in gas (Rg) and air (Ra); Rg/Ra= 65 @ 20 ppm), a low detection limit (Rg/Ra= 6 @ 500 ppb), wide dynamic response (Rg/Ra= 190 @ 80 ppm), strong stability (30 days), and 21.6 times higher sensitivity than pure CuO at RT toward 20 ppm of DEA. The exceptional gas-sensing behavior can be attributed to various factors, including controlled annealing conditions that result in the formation of well-defined structures and greater porosity, efficient charge transfer properties resulting from an optimized ratio of g-C3N4 to CuO in HPHSs, an abundance of defects, unsaturated Cu sites, and synergistic effects. The study presents a universal strategy for generating sensitive and selective g-C3N4-based composite materials for low-temperature gas sensors.

Technological developments and accelerator improvements for the FRIB beam power ramp-up

The Facility for Rare Isotope Beams (FRIB) began operation with 1 kW beam power for scientific users in May 2022 upon completion of 8 years of project construction. The ramp-up to the ultimate beam power of 400 kW, planned over a 6-year period, will enable the facility to reach its full potential for scientific discovery in isotope science and applications. In December 2023, a record-high beam power of 10.4 kW uranium was delivered to the target. Technological developments and accelerator improvements are being made over the entire facility and are key to completion of the power ramp-up. Major technological developments entail the phased deployment of high-power beam-intercepting systems, including the charge strippers, the charge selection systems, the production target, and the beam dump, along with support systems, including non-conventional utilities (NCU) and remote handling facilities. Major accelerator improvements include renovations to aging legacy systems associated with experimental beam lines and system automation for improved operational efficiency and better machine availability. Experience must be gained to safely handle the increased radiological impacts associated with high beam power; extensive machine studies and advanced beam tuning procedures are needed to minimize uncontrolled beam losses for the desired operating conditions. This paper discusses the technological developments and accelerator improvements with emphasis on major R&D efforts.

Acid-resistant polyamide-sulphonamide nanofiltration membrane with positive charge for efficient removal of dyes/metal ions in acidic wastewater

The selection of separability and surface positive charge is of significant importance for treating acidic industrial wastewater with acid-resistant nanofiltration (NF) membranes. In this work, polyvinylidenefluoride (PVDF) flat membrane was used as the base membrane material, with polyethyleneimine (PEI) as the aqueous monomer and trimesoyl chloride (TMC)/benzene-1,3-disulfonyl chloride (BDSC) as the organic phase monomers, to prepare PEI-polyamide-sulphonamide (PASA) NF membrane through interfacial polymerization (IP). The influence of reaction conditions on membrane separation performance and corrosion resistance were studied, and the performance differences of the membrane under different ratios of TMC and BDSC were explored. PEI-PASA NF membrane was characterized by FTIR, XPS, SEM, contact angle tester, and mechanical strength tester. The results showed that the PEI-PASA NF membrane prepared under optimal conditions had a strong positive charge on the surface, with a water flux of 17.54 L·m−2·h−1 at 5 bar, and after static assessments in 10 % H2SO4 solution at 55 °C for 24 h, the methyl orange rejection remained kept over 95 %; after dynamic filtration in 1 % HCl for 120 h, the rejection performance of the membrane remained stable (FeCl3 96.88 %, CuCl2 93.72 %), indicating the potential application inharsh conditions, especially acid wastewater treatment.

Molecular Dynamics Simulations of Claudin-10a and -10b Ion Channels: With Similar Architecture, Different Pore Linings Determine the Opposite Charge Selectivity.

Claudin polymers constitute the tight junction (TJ) backbone that forms paracellular barriers, at least for bigger solutes. While some claudins also seal the barrier for small electrolytes, others form ion channels. For cation-selective claudin-15 and claudin-10b, structural models of channels embedded in homo-polymeric strands have been suggested. Here, we generated a model for the prototypic anion-selective claudin-10a channel. Based on previously established claudin-10b models, dodecamer homology models of claudin-10a embedded in two membranes were analyzed by molecular dynamics simulations. The results indicate that both claudin-10 isoforms share the same strand and channel architecture: Sidewise unsealed tetrameric pore scaffolds are interlocked with adjacent pores via the β1β2 loop of extracellular segment 1. This leads to TJ-like strands with claudin subunits arranged in four joined rows in two opposing membranes. Several but not all cis- and trans-interaction modes are indicated to be conserved among claudin-10a, -10b, and -15. However, pore-lining residues that differ between claudin-10a and -10b (i.e., R33/I35, A34/D36, K69/A71, N54/D56, H60/N62, R62/K64) result in opposite charge selectivity of channels. This was supported by electric field simulations for both claudins and is consistent with previous electrophysiological studies. In summary, for the first time, a structural and mechanistic model of complete and prototypic paracellular anion channels is provided. This improves understanding of epithelial paracellular transport.

Plasma‐oxidized 2D MXenes subnanochannel membrane for high‐performance osmotic energy conversion

AbstractNanofluidic channels inspired by electric eels open a new era of efficient harvesting of clean blue osmotic energy from salinity gradients. Limited by less charge and weak ion selectivity of the raw material itself, energy conversion through nanofluidic channels is still facing considerable challenges. Here, a facile and efficient strategy to enhance osmotic energy harvesting based on drastically increasing surface charge density of MXenes subnanochannels via oxygen plasma is proposed. This plasma could break Ti–C bonds in the MXenes subnanochannels and effectively facilitate the formation of more Ti–O, C═O, O–OH, and rutile with a stronger negative charge and work function, which leads the surface potential of MXenes membrane to increase from 205 to 430 mV. This significant rise of surface charge endows the MXenes membrane with high cation selectivity, which could make the output power density of the MXenes membrane increase by 248.2%, reaching a high value of 5.92 W m−2 in the artificial sea‐river water system. Furthermore, with the assistance of low‐quality heat at 50°C, the osmotic power is enhanced to an ultrahigh value of 9.68 W m−2, which outperforms those of the state‐of‐the‐art two‐dimensional (2D) nanochannel membranes. This exciting breakthrough demonstrates the enormous potential of the facile plasma‐treated 2D membranes for osmotic energy harvesting.

All-Inorganic Hydrothermally Processed Semitransparent Sb2S3 Solar Cells with CuSCN as the Hole Transport Layer.

An inorganic wide-bandgap hole transport layer (HTL), copper(I) thiocyanate (CuSCN), is employed in inorganic planar hydrothermally deposited Sb2S3 solar cells. With excellent hole transport properties and uniform compact morphology, the solution-processed CuSCN layer suppresses the leakage current and improves charge selectivity in an n-i-p-type solar cell structure. The device without the HTL (FTO/CdS/Sb2S3/Au) delivers a modest power conversion efficiency (PCE) of 1.54%, which increases to 2.46% with the introduction of CuSCN (FTO/CdS/Sb2S3/CuSCN/Au). This PCE is a significant improvement compared with the previous reports of planar Sb2S3 solar cells employing CuSCN. CuSCN is therefore a promising alternative to expensive and inherently unstable organic HTLs. In addition, CuSCN makes an excellent optically transparent (with average transmittance >90% in the visible region) and shunt-blocking HTL layer in pinhole-prone ultrathin (<100 nm) semitransparent absorber layers grown by green and facile hydrothermal deposition. A semitransparent device is fabricated using an ultrathin Au layer (∼10 nm) with a PCE of 2.13% and an average visible transmittance of 13.7%.

Leaf-like ZIF-L as self-sacrificed template via acid induced removal for stronger negatively charged PES membranes based on RTIPS method

In this paper, ZIF-L was blended with citric acid (CA) and polyethersulfone (PES) to prepare a casting solution. A novel negatively charged ultrafiltration (UF) membrane (ZIF-L/CA/PES) was obtained using the reverse thermally induced phase separation (RTIPS) method. The hydrophilic carboxyl groups present in CA not only imparted high hydrophilicity and negative charge to the membrane surface, enhancing the membrane’s selectivity and contamination resistance, but also created an acidic environment to attack the Zn atoms in ZIF-L by the ionized H+ from CA, resulting in the generation of micro-defective pores and an improvement in permeability. Additionally, the results showed that membranes generated through the RTIPS process exhibit uniform porous surfaces and spongy cross-sections, enhancing membrane performance. The optimized membranes demonstrated the capability to achieve a pure water flux of up to 2267 L/m2h with 93.1 % humic acid (HA) retention, and a remarkable membrane flux recovery rate of 75.8 %, suggesting the crucial roles played by CA and ZIF-L in the separation process. In conclusion, hydrophilic anti-fouling UF membranes with a high negative charge and excellent permeation selectivity were fabricated by establishing micro-defective channels through the incorporation of carboxylic acid and ZIF-L, combined with the RTIPS process.

Efficient Electrochemical Lead Detection by a Histidine-Grafted Metal-Organic Framework MOF-808 Electrode Material.

As the excessive presence of heavy metals in the environment significantly affects human health, it becomes necessary to develop efficient, selective, and sensitive methods for their detection. In this study, a novel electrochemical sensor for the detection of Pb2+ ions is described. The proposed sensor is based on a glassy carbon electrode (GCE) modified by a thin film of histidine-grafted metal-organic framework (MOF-808-His). The MOF-808 was obtained solvothermally, and then postsynthetically modified by substituting the coordinated acetate with histidinate. By electrochemistry, the MOF-808-His-modified GCE demonstrated high charge selectivity, while electrochemical impedance spectroscopy (EIS) and kinetic studies gave a lower charge transfer resistance (4196 Ω) and a better standard heterogeneous electron transfer rate constant (1.80 × 10-5 cm s-1) on MOF-808-modified GCE. These results indicated a swift and direct electron transfer rate from [Fe(CN)6]3-/4- to the electrode surface. Using square wave anodic stripping voltammetry (SWASV), the rapid and highly sensitive determination of Pb2+ was achieved on MOF-808-His-modified GCE. By optimizing the accumulation-detection parameters including pH of the detection medium, deposition time and potential, and concentration, a remarkable limit of detection (LoD, based on a signal-to-noise ratio of 3) of (1.12 × 10-10 ± 0.10 × 10-10) mol L-1 was obtained, with a sensitivity of (9.6 ± 0.1) μA L μmol-1. After interference and stability studies, the MOF-808-His-modified GCE was applied to the detection of Pb2+ in a tap water sample with a concentration of 10 μmol L-1 Pb2+.

Micromolding-Assisted Production of SERS-Active Microcylinders for Size- and Charge-Selective Molecular Detection.

Surface-enhanced Raman scattering (SERS) is an effective technique for amplifying the Raman signal of molecules by using metal nanostructures. However, these metal surfaces are susceptible to contamination by undesirable adhesives in complex mixtures, typically necessitating a time-consuming and costly sample pretreatment. In order to circumvent this, metal nanoparticles have been uniformly embedded within microgels by using microfluidics. In this work, we introduce a simple, scalable micromolding method for creating SERS-active cylindrical microgels designed to eliminate the need for pretreatment. These microcylinders are created through the simultaneous photoreduction and photo-cross-linking of precursor solutions. These solutions are optimized for consistent, high-intensity Raman signals as well as molecular size and charge selectivity. A sequential micromolding method is employed to design dual-compartment microcylinders, offering additional functionalities such as optical encoding, magnetoresponsiveness, and dual-charge selectivity. These SERS-active microcylinders provide robust Raman signals of small molecules, even in the presence of adhesive proteins, without compromising sensitivity. To demonstrate this capability, we directly detect pyocyanin in saliva and tartrazine in whole milk without any need for sample pretreatment.

Facile synthesis of ionic liquid mobilized ZnO@Ti3C2Tx composite nanosheets for high charged transfer, sensitive and selective electrochemical detection of 5-flurouracil in waste water and urine samples

Controlling and monitoring the concentration of anticancer drugs in physiological fluids and water bodies are crucial for successful cancer treatment and environmental considerations. However, the development of electrochemical-based sensors having high charge transfer rate, high conductivity, sensitivity and selectivity for anticancer drugs (ACDs) have been limited research due to their poor oxidation–reduction behaviour and complex structures. To address this issue, we pursuit a simple and efficient synthesis route of zinc nanowires (ZnO NWs) decorated on MXene (Ti3C2Tx) nanosheets and utilized for the electrochemical detection of antimetabolite drug namely, 5-fluorouracil (5-FU). We enhance the charge transfer between two nanostructures by incorporating an ionic liquid (ILs). Detailed spectroscopic analysis demonstrates the interaction between ZnO and MXene, which is further improved by the addition of ILs through metal–oxygen bonds. XRD patterns also indicated an intensity reduction and shifting of the MXene’s (002) peak which supporting the spectroscopic results. Moreover, the results confirm that ILs enhance the interfacial connectivity between ZnO NWs and MXene nanosheets through electrostatic interactions, improving the charge transfer rate, sensing capability, and signal intensity for anticancer drug detection. The optimized ILs_ZnO@MX composite exhibits a 10-fold lower limit of detection for 5-FU (0.03 µM) compared to bare ZnO@MX.