Specific Chemical Interactions Research Articles

Surface-Immobilized Ionophore Electric-Double-Layer (EDL) Extended-Gate Field-Effect Transistors for High Sensitivity to Detection of Mercury and Lead Ions

In the field of sensors, particularly in FETs (Field-Effect Transistors), they have emerged as a promising solution for detecting heavy metal ions. These sensors offer high sensitivity, rapid response, compact and portable device sizes, and the potential for low cost. These advantages have led to their successful application in monitoring drinking water, environmental samples, and industrial wastewater, enabling rapid on-site detection of heavy metal ions.At the molecular level, certain organic molecules or coordination compounds can selectively bind to specific ions through specific chemical reactions or coordination interactions. Therefore, designing ionophores specifically for capturing or transporting particular types of ions is possible. Previous research has employed the mechanism of Ion Selective Membranes (ISM) for detecting heavy metals. However, ISMs are typically polymer coatings applied through spinning, resulting in a thick layer that leads to longer diffusion times, requiring 15 minutes or more to achieve baseline stability, with a detection limit of µM to nM .Many studies have also utilized aptamers for detecting metal ions, but aptamers are typically expensive and require controlled formation of specific structures to bind with ions. They are susceptible to interference signals from pH value or salt concentrations.In environmental or food samples, the presence of heavy metals often needs to be detected. Electric-Double-layer (EDL) sensors exhibit better stability, with a monolayer recognition layer providing shorter detection times and higher sensitivity. This study successfully developed FET (Field-Effect Transistor) metal ionophores based on a specially designed ionophore with a double-layer expanded gate, including mercury ionophore sensors and lead ionophore sensors. By defining a gate sensing area with dimensions of 500 μm x 500 μm, significant detection limits of nM to pM were achieved within minutes. The combination of FETs, EDL, and ionophores in this study's development has resulted in highly efficient, sensitive, selective, and portable detection instruments. Keywords: MOSFET, EDL, Aptamer, Ionophore, Heavy metal Figure 1

Nano-Strand Formation via Gas Phase Reactions from Al-Co-Fe Reacted with CaF2-SiO2-Al2O3-MgO Flux at 1350 °C: SEM Study and Thermochemistry Calculations

The submerged arc welding (SAW) process is operated at high temperatures, up to 2500 °C, in the arc cavity formed by molten oxy-fluoride flux (slag). These high arc cavity temperatures and the complex interaction of gas–slag–metal reactions in a small space below the arc render the study of specific chemical interactions difficult. The importance of gas phase reactions in the arc cavity of the SAW process is well established. A low-temperature (1350 °C) experimental method was applied to simulate and study the vaporisation and re-condensation behaviour of the gas species emanating from oxy-fluoride flux. Energy dispersive X-ray spectroscopy (EDX) analyses and reaction thermochemistry calculations were combined to explain the role of Al as a de-oxidiser element in gas phase chemistry and, consequently, in nano-strand formation reactions. EDX element maps showed that the nano-strands contain elemental Ti only, and the nano-strand end-caps contain Co-Mn-Fe fluoride. This indicates a sequence of condensation reactions, as Ti in the gas phase is re-condensed first to form the nano-strands and the end-caps formed from subsequent re-condensation of Co-Mn-Fe fluorides. The nano-strand diameters are approximately 120 nm to 360 nm. The end-cap diameter typically matches the nano-strand diameter. Thermochemical calculations in terms of simple reactions confirm the likely formation of the nanofeatures from the gas phase species due to the Al displacement of metals from their metal fluoride gas species according to the reaction: yAl + xMFy ↔ xM + yAlFx. The gas–slag–metal equilibrium model shows that TiO2 in the flux is transformed into TiF3 gas. Formation of Ti nano-strands is possible via displacement of Ti from TiF3 by Al to form Al-fluoride gas.

Ultrasonic-assisted synthesis of CaCu3Ti4O12/reduced graphene oxide composites for enhanced photocatalytic degradation of pharmaceutical products: Ibuprofen and Ciprofloxacin.

The objective of this research is to create a highly effective approach for eliminating pollutants from the environment through the process of photocatalytic degradation. The study centers around the production of composites consisting of CaCu3Ti4O12 (CCTO) and reduced graphene oxide (rGO) using an ultrasonic-assisted method, with a focus on their capacity to degrade ibuprofen (IBF) and ciprofloxacin (CIP) via photodegradation. The impact of rGO on the structure, morphology, and optical properties of CCTO was inspected using XRD, FTIR, Raman, FESEM, XPS, BET, and UV-Vis. Morphology characterization showed that rGO particles were dispersed within the CCTO matrix without any specific chemical interaction between CCTO and C in the rGO. The BET analysis revealed that with increasing the amount of rGO in the composite, the specific surface area significantly increased compared to the CCTO standalone. Besides, increasing rGO resulted in a reduction in the optical bandgap energy to around 2.09 eV, makes it highly promising photocatalyst for environmental applications. The photodegradation of IBF and CIP was monitored using visible light irradiation. The results revealed that both components were degraded above 97% after 60 min. The photocatalyst showed an excellent reusability performance with a slight decrease after five runs to 93% photodegradation efficiency.

Exploring the synergistic effects of amoxicillin and methylene blue on unsaturated lipid structures: A study of Langmuir monolayers and giant unilamellar vesicles

The potentially toxic effects of emerging pollutant mixtures often deviate from the individual compound effects, presenting additive, synergistic, or agonistic interactions. This study delves into the complex world of emerging pollutants' mixtures, with a particular focus on their potential impact on unsaturated lipid DOPC (1,2-dioleoyl-sn-glycerol-3-phosphocholine) structured as both monolayers and bilayers, which are valuable tools for mimicking cell membranes. Specifically, we examine the effects of two common types of pollutants: antibiotics (amoxicillin) and dyes (methylene blue). Utilizing Langmuir monolayers, our research reveals a synergistic effect within the pollutant mixture, as evidenced by pressure-area isotherms and polarization-modulated infrared reflection absorption spectroscopy. We identify the specific chemical interactions contributing to this synergistic effect. Furthermore, through contrast phase microscopy experiments on giant unilamellar vesicles (bilayer system), we find that the individual pollutants and the mixture exhibit similar molecular effects on the bilayer, revealing that the molecular size is a key factor in the bilayer-mixture of pollutant interaction. This highlights the importance of considering molecular size in the interactions with bilayer systems. In summary, our research dissects the critical factors of chemical interactions and molecular size concerning the effects of pollutants on DOPC, serving as simplified models of cell membranes. This study underscores the significance of comprehending the molecular effects of emerging pollutants on human health and the development of models for exploring their intricate interactions with cell membranes.

(Invited) A Multifunctional Polynorbonene Binder System Enabling Next-Generation Lithium-Ion Batteries

Polynobornene (PNBE), a material commonly used in your shoes or for the tires of supercars, can also be highly influential to the development of next-generation batteries (Kim et al., 2022). When designing the batteries of tomorrow, we are interested in polymeric materials with precisely defined dynamic mechanical properties, increased ionic or conductivity, specific chemical interactions and moonshots like stable and healable interfaces (Lopez et al., 2019). PNBE provides high chemical and thermal stability, low shrinkage, and strong adhesion properties that lead to enhanced electrode stability and electrical conductivity(Le et al., 2020). Possessing a highly flexible nature allows PNBE to conform to the shape of an electrode – making PNBE an ideal multifunctional binder.Consider some persisting problems associated with batteries, for example Si electrodes typically fail due to cracks in the Si particles creating new surfaces for electrolyte decomposition/solid electrolyte interphase formation, and due to the Si becoming electrically disconnected from the rest of the electrode and ultimately terminating cycling (Ryu et al., 2004) . PNBE can address both aforementioned pain points, low shrinkage and flexibility can help mitigate the impact of cracking that occurs within an electrode over time by maintaining the structural integrity, and strong adhesion properties promote effective binding of the active material and the rest of the electrode. With increasing concerns about cobalt, there has been a move to replace oxides with phosphates. Substituting a substantial fraction of Mn, for Fe in LiFePO4 leads to a material with an energy density approaching that of the oxides, while substantially lessening environmental concerns. Unfortunately, Mn dissolution causes a poor cycle lifetime.In an effort to reduce Mn dissolution, a mixture of PNBE and PVDF was used as a binder system. The PNBE was designed to have ether-type comb-branch functionalities that aid in Mn trapping, while the PVDF had suitable viscosity and mechanical properties. Figure 1 shows cycle lifetime results conducted at 45°C on a 2Ah LMFP-Graphite cell containing a 4%PVDF/1%PNBE binder system. The results show very good lifetime, with the capacity retention nearly 90% after 1,000 cycles. Given the difficulty with cycling of LMFP due to Mn dissolution, these results show good promise for this approach.This talk will highlight the opportunities and challenges of custom and enabling PNBE binder systems for LMFP, and other battery systems. References Kim, N.-Y., Moon, J., Ryou, M.-H., Kim, S.-H., Kim, J.-H., Kim, J.-M., Bang, J., & Lee, S.-Y. (2022). Amphiphilic Bottlebrush Polymeric Binders for High-Mass-Loading Cathodes in Lithium-Ion Batteries. Advanced Energy Materials, 12(1), 2102109. https://doi.org/https://doi.org/10.1002/aenm.202102109Le, D., Samart, C., Lee, J.-T., Nomura, K., Kongparakul, S., & Kiatkamjornwong, S. (2020). Norbornene-Functionalized Plant Oils for Biobased Thermoset Films and Binders of Silicon-Graphite Composite Electrodes. ACS Omega, 5(46), 29678–29687. https://doi.org/10.1021/acsomega.0c02645Lopez, J., Mackanic, D. G., Cui, Y., & Bao, Z. (2019). Designing polymers for advanced battery chemistries. Nature Reviews Materials, 4(5), 312–330. https://doi.org/10.1038/s41578-019-0103-6Ryu, J. H., Kim, J. W., Sung, Y.-E., & Oh, S. M. (2004). Failure Modes of Silicon Powder Negative Electrode in Lithium Secondary Batteries. Electrochemical and Solid-State Letters, 7(10), A306. https://doi.org/10.1149/1.1792242 Figure 1

"Common-Precursor" Protein Mimetic Approach to Rescue Aβ Aggregation-Mediated Alzheimer's Phenotypes.

Abberent protein-protein interactions (aPPIs) are associated with an array of pathological conditions, which make them important therapeutic targets. The aPPIs are mediated via specific chemical interactions that spread over a large and hydrophobic surface. Therefore, ligands that can complement the surface topography and chemical fingerprints could manipulate aPPIs. Oligopyridylamides (OPs) are synthetic protein mimetics that have been shown to manipulate aPPIs. However, the previous OP library used to disrupt these aPPIs was moderate in number (∼30 OPs) with very limited chemical diversity. The onus is on the laborious and time-consuming synthetic pathways with multiple chromatography steps. We have developed a novel chromatography-free technique to synthesize a highly diverse chemical library of OPs using a "common-precursor" approach. We significantly expanded the chemical diversity of OPs using a chromatography-free high-yielding method. To validate our novel approach, we have synthesized an OP with identical chemical diversity to a pre-existing OP-based potent inhibitor of Aβ aggregation, a process central to Alzheimer's disease (AD). The newly synthesized OP ligand (RD242) was very potent in inhibiting Aβ aggregation and rescuing AD phenotypes in an in vivo model. Moreover, RD242 was very effective in rescuing AD phenotypes in a post-disease onset AD model. We envision that our "common-precursor" synthetic approach will have tremendous potential as it is expandable for other oligoamide scaffolds to enhance affinity for disease-relevant targets.

Colloidal and solid phase partitioning between ferrihydrite, humic acid and copper coprecipitates

Our understanding of the interactions between Fe oxides, humic acids (C), and Cu precipitation products in the environment are limited by our ability to measure specific forms and chemical interactions. Here, we examine the effect of solution pH, Fe:C molar ratio from 1:0 to 1:3, and Cu concentration on dissolved and colloidal Cu concentrations after sorption (SOR) or coprecipitation (CPT) reactions. This included specifically measuring the colloidal phases formed using asymmetrical flow field flow fractionation coupled to a total organic carbon analyzer and an inductively coupled plasma mass spectrometer. In the case of 1:0 Fe:C reactions, more Cu was associated with bulk solids and colloidal solids in CPT reaction products, particularly at pH 5 and 6. As C content increased, precipitation reactions led to more Cu retained in the bulk solid phase at lower pH, but more in the dissolved and colloidal phase at higher pH. Of the colloids formed at pH 7, about 10% of the dissolved Cu is present as Fe–C–Cu ternary phases, with the remainder as Cu–C or inorganic Cu phases, yet at pH 6, only Fe–Cu colloids were observed. Applying an additivity approach while using a NICA-Donnan C complexation model combined with a ferrihydrite surface complexation model, the model often predicts higher than observed dissolved Cu in CPT reactions with no C present, but lower than observed dissolved Cu with C present. In applying the model specifically to colloidal phases, much lower concentrations of colloid bound Cu is predicted than observed in the 1:0 Fe:C scenario, but as C content increases, more colloidal Cu is predicted than observed. Given the availability and lability of Cu in environmental systems is assumed to correspond to dissolved Cu, this work notes some differences in the dissolved and colloidal phases formed in different contexts.

Mucus-Inspired Dynamic Hydrogels: Synthesis and Future Perspectives.

Mucus hydrogels at biointerfaces are crucial for protecting against foreign pathogens and for the biological functions of the underlying cells. Since mucus can bind to and host both viruses and bacteria, establishing a synthetic model system that can emulate the properties and functions of native mucus and can be synthesized at large scale would revolutionize the mucus-related research that is essential for understanding the pathways of many infectious diseases. The synthesis of such biofunctional hydrogels in the laboratory is highly challenging, owing to their complex chemical compositions and the specific chemical interactions that occur throughout the gel network. In this perspective, we discuss the basic chemical structures and diverse physicochemical interactions responsible for the unique properties and functions of mucus hydrogels. We scrutinize the different approaches for preparing mucus-inspired hydrogels, with specific examples. We also discuss recent research and what it reveals about the challenges that must be addressed and the opportunities to be considered to achieve desirable de novo synthetic mucus hydrogels.

Molecular mechanisms of spontaneous curvature and softening in complex lipid bilayer mixtures

Membrane reshaping is an essential biological process. The chemical composition of lipid membranes determines their mechanical properties and thus the energetics of their shape. Hundreds of distinct lipid species make up native bilayers, and this diversity complicates efforts to uncover what compositional factors drive membrane stability in cells. Simplifying assumptions, therefore, are used to generate quantitative predictions of bilayer dynamics based on lipid composition. One assumption commonly used is that “per lipid” mechanical properties are both additive and constant—that they are an intrinsic property of lipids independent of the surrounding composition. Related to this is the assumption that lipid bulkiness, or “shape,” determines its curvature preference, independently of context. In this study, all-atom molecular dynamics simulations on three separate multilipid systems were used to explicitly test these assumptions, applying methodology recently developed to isolate properties of single lipids or nanometer-scale patches of lipids. The curvature preference experienced by populations of lipid conformations were inferred from their redistribution on a dynamically fluctuating bilayer. Representative populations were extracted by both structural similarity and semi-automated hidden Markov model analysis. The curvature preferences of lipid dimers were then determined and compared with an additive model that combines the monomer curvature preference of both the individual lipids. In all three systems, we identified conformational subpopulations of lipid dimers that showed non-additive curvature preference, in each case mediated by a special chemical interaction (e.g., hydrogen bonding). Our study highlights the importance of specific chemical interactions between lipids in multicomponent bilayers and the impact of interactions on bilayer stiffness. We identify two mechanisms of bilayer softening: diffusional softening, driven by the dynamic coupling between lipid distributions and membrane undulations, and conformational softening, driven by the inter-conversion between distinct dimeric conformations.

Recent progress on three-dimensional nanoarchitecture anode materials for lithium/sodium storage

High-performance batteries with high density and low cost are needed for the development of large-scale energy storage fields such as electric vehicles and renewable energy systems. The anode with three-dimensional (3D) nanoarchitecture is one of the most attractive candidates for high-performance lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to its efficient electron/ion transport and high active material mass loading. Although some important breakthroughs have been made in 3D nanoarchitecture anode materials, more improvements are still needed for high cycling stability and high energy density. Herein, the latest research progress of 3D nanoarchitecture anode materials for LIBs and SIBs is reviewed, including nanoporous metal, nanoporous graphene, and their derived foams. Specifically, the storage properties of Li/Na ions, the kinetics of ion/electron transport, and specific chemical interactions are discussed based on the structure design. In addition, the research strategies and structural characteristics of 3D nanoarchitecture anode materials are summarized, providing a reference for the further development of LIBs and SIBs. Meanwhile, the future research directions of LIBs and SIBs have also prospected.

Nanoscale engineering to control mass transfer on carbon-based electrodes

Here we use an electrode consisting of carbon nanofibers (CNFs), the lengths and surface population density of which can be effectively controlled. It is shown that (i) a thin liquid layer forms when the thickness of the diffusion layer has a specific ratio to the dimensions of the nanostructured carbon surface. (ii) This leads to a decrease in the peak potential difference and a subsequent increase in the apparent heterogeneous electron transfer (HET) constant, both of which could be interpreted as a result of increased catalytic activity. (iii) However, we show that this explanation is not likely, as our materials are chemically identical, and we use an outer sphere redox (OSR) probe to minimize any specific chemical interactions. On the contrary, (iv) the results clearly show that the observed behavior is caused by a combination of the formation of a thin liquid layer and the increased apparent surface area of the electrodes.

Influence of relative humidity on CO2 interaction mechanism for Gd-doped SnO2 with respect to pure SnO2 and Gd2O3

The paper aims to identify the CO2 interaction mechanism for chemical sensors based on Gd-doped SnO2, SnO2 and Gd2O3 powders deposited as thick sensitive layers. The low reactivity of CO2 conferred by the thermodynamic stability and chemical inertia can be offset by the presence of relative humidity. The sensitive powders were prepared by wet chemical co-precipitation method. The Gd concentration was varied from 1% to 20 at% in order to determine the limit for Gd integration as a doping ion prior to chemical segregation as a secondary phase. Analytical transmission electron microscopy points to a homogeneous Gd doping of the nanostructured SnO2 powders for low doping concentrations and the formation of a nanocomposite based on SnO2 as main phase and cubic Gd2O3 as secondary phase for the highly doped samples. The electrical resistance is either influenced by the density of oxygen vacancies, or is the result of compensation for two opposite behaviours into the SnO2-Gd2O3 nanocomposite structures. The CO2 exposure to humid atmosphere determines distinct behaviours corresponding to SnO2 and Gd2O3 as constitutive elements. The associated CO2 interaction mechanism is based on simultaneous DC electrical resistance and Contact Potential Difference measurements, which allow decoupling the ionosorption from the dipolar processes, thus highlighting specific chemical interactions on the SnO2 and Gd2O3 surfaces.

Wettability of carbon nanotube-grafted carbon fibers and their interfacial properties in polypropylene thermoplastic composite

The interfacial properties of carbon fiber (CF) reinforced thermoplastic composites depend strongly on the wettability and surface characteristics of the reinforcing fibers, and their compatibility with a chosen matrix. The interface between conventional fibers and thermoplastic matrices is generally weak, due to a lack of specific chemical interaction, especially in the case of polyolefins. Carbon nanotube-grafted-carbon fibers (CNT-g-CF) are considered to be potential reinforcements as they provide additional mechanical interlocking. Commercial CFs were successfully grafted with nanotubes using a continuous, and hence scalable, CVD method. X-ray photoelectron spectroscopy, Wilhelmy wetting measurements, and scanning electron microscopy confirmed the successful grafting and resulting hydrophobic surface chemistry, dominated by van der Waals interactions. The grafted CNTs, with diameters and lengths around 10 nm and 140 nm respectively, were well suited to improve the overall wettability and interfacial shear strength (+53.4 %) of the CNT-g-CF in a polypropylene matrix when compared to as-received unsized CFs.

The Ionic Composition and Chemistry of Nanopore-Confined Solutions.

There is increasing interest in understanding the properties of solutions confined within nanotubes and synthetic or biological nanopores. How the ionic content of a nanopore-confined solution differs from that of a contacting bulk salt solution is of particular importance, for example, to water desalinization, industrial electrolysis, and all living systems. This paper explores ionic content, ionic interactions, and ion-transport properties of solutions confined within the 10 nm diameter pores of a synthetic polymer membrane. The membrane has a fixed negative pore-wall and surface charge due to ionizable carbonate groups. As a result, under some conditions, the nanopore-confined solution contains only cations and no anions or salt present in a contacting solution, ideal cation permselectivity. This anion- and salt-rejecting ability varies greatly with the cation of the salt, a result that is in contradiction to the prevailing model for permselectivity in nanopores. The extant model fails because it does not account for specific chemical interactions between the cation and the carbonate groups. The nature of these ion-selective interactions is discussed here.

Triple-ligand zeolitic imidazolate frameworks for highly CO2 selective mixed matrix membranes

• A series of triple ligand-coordinated ZIF-8s (TAZIF-8s) were successfully prepared. • The TAZIF-8s enhanced chemical interaction and molecular sieving ability toward CO 2 . • A high dispersibility of TAZIF-8s enabled high TAZIF-8 loading (40 wt%) mixed matrix membranes (MMMs). • TAZIF-8 MMMs effectively suppressed both the physical aging and CO 2 -induced plasticization. • High CO 2 separation performance of TAZIF-8 MMMs was retained even after water vapor exposure. Here, we report a new class of highly CO 2 selective ZIF nanoparticles, TAZIF-8, consisting of zinc metals and triple ligands, including 2-methylimidazole (MIm), tributylamine (TBA), and 3-amino-1,2,4-triazole (Atz). The Zn-MIm coordination retains an open porous sodalite topology, while the Zn-TBA analogue contributes to high processability. Lastly, the Zn-Atz coordination enables favorable CO 2 permeation via a combination of enhanced size discrimination and specific chemical interactions. A high loading 6FDA-DAM/TAZIF-8 (40 wt%) mixed matrix membrane consequently exhibits an almost threefold increase in CO 2 permeability and a twofold increase in CO 2 selectivity over other light gases (N 2 , CO, or CH 4 ) compared to high performance 6FDA-DAM membrane. Furthermore, it maintains excellent CO 2 separation performance over 90 days and even after exposure to water vapor. Our multiple hybrid modification technique enables the fine-tuning of the physical structure and textural properties of ZIF for enhanced CO 2 separation performance.

Ring Homopolymers Prefer Crumpling into Odd‐Length Segments

AbstractBy studying the collapse of a simple ring homopolymer devoid of solvent interactions and chemical heterogeneity, it is shown that segments with an odd number of low‐energy dihedral angles are unusually frequent. The prevalence of odd‐size segments is due to the greater decrease in end‐to‐end length as compared with crumpling to even‐size segments. These results suggest that the sizes of some conformational features of polymers may arise, not due to specific chemical interactions, but rather from generic characteristics of polymers.

Nanoencapsulation of essential oils from industrial hemp (Cannabis sativa L.) by-products into alfalfa protein nanoparticles

Essential oils of industrial hemp (Cannabis sativa L.) by-products (HBEO) were characterized by gas chromatography-mass spectrometry (GC–MS); then, encapsulated in alfalfa protein isolate nanoparticles (API-NPs) as a novel nanocarrier. A desirable retention (45.5–63.4%) of HBEO within API-NPs was confirmed. These nanoparticles exhibited a shrunk and globular shape with a size range of 156.9–325.9 nm as indicated by dynamic light scattering (DLS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Furthermore, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and thermal analyses corroborated that HBEO was successfully encapsulated within API NPs in an amorphous form without specific chemical interaction with the carrier matrix. The antioxidant activity of loaded HBEO into API-NPs was higher than free HBEO implying that encapsulation of HBEO in API-NPs was an efficient strategy for improving its stability and functionality. HBEO-loaded API-NPs is a promising candidate to be used in future foods and supplements for novel applications.

Bifunctional biohybrid magnetically propelled microswimmer

Inspired by the intrinsic helical structures of vessels in banana leaves, a novel bifunctional biohybrid magnetic microswimmer with both environment remediation and biomedical application was synthesized by a simple chemical method. Here, spiral vessels isolated from banana leaves were used as biological templates, where nickel layers with magnetic properties and Fe3+-TA (tannic acid, TA) films with pH-dependent degradation capabilities were modified on their surfaces by simple chemical reactions in solution at room temperature. The obtained magnetic helical (Helix/Ni/Fe3+-TA) microswimmers can be efficiently propelled in either pollutant solution (rhodamine B, RhB) or biofluid solution (DMEM culture medium and fetal bovine serum) in the presence of a magnetic field. The developed Helix/Ni/Fe3+-TA microswimmers can be used to efficiently degrade organic pollutant RhB due to the Fe3+-TA films which can produce reactive oxygen species under the action of hydrogen peroxide (H2O2). Moreover, due to the specific chemical interaction between the microswimmers and the surface of cancer cells, the microswimmers can precisely capture cancer cells and then produce heat under light irradiation to kill those cells. These novel helical microswimmers with simple and economic fabrication, efficient magnetic propulsion and diverse functionality show great potential in future environmental and biological applications.

A March to Shape Optical Artificial Olfactory System toward Ultrasensitive Detection of Improvised Explosives

Improvised explosives (IEs) have been frequently used in explosion‐based terrorist attacks, and have aroused widespread concerns from governments to academic societies. Due to the fact that IEs mostly exist as solids, there is a pressing demand for sensors to adapt to acquire the information from the solid state. Chemical sensors usually comprise with probes designed based on the chemical properties of the analytes, and generate signals through specific chemical interactions, which would not be affected by the state of the target substance. Colorimetry and fluorescence, known for their intuitionistic (recognizable by human eyes), portable (independent of large‐scale analytical equipment), highly specific, sensitive, and environmental interference‐free characteristics, are commonly adopted optical chemical detection methods in materials analysis and environmental monitoring. Based on this, the exploration of optical artificial olfactory system, which mimics the working principle of natural olfactory system and acquires sensing signal by optical methods, has emerged to be a promising tool for IEs detection. Here, the basic working principle and the necessary components of optical artificial olfactory system are recommended, including probe molecule, array composition, pattern recognition and device construction. The potential development direction employing molecular recognition of IEs, generation, and acquisition methodology of optical signals are also prospected.

Chemical design of self-propelled Janus droplets

Chemical design of self-propelled Janus droplets