Wearable biosensors are gaining significant attention for their ability to monitor vital health signs remotely, continuously, and non-invasively. Nanomaterials offer transformative potential for next-generation soft wearable sensors, enabling seamless skin integration with enhanced comfort and data accuracy. Wet chemistry provides a scalable, cost-effective approach to producing nanomaterials, transforming rigid sensors into soft, flexible, and stretchable devices for broader wearable applications. This review highlights recent advances in soft wearable biosensors based on wet chemically produced nanomaterials, including metals, carbons, conducting polymers, conductive hydrogels, and liquid metals. It discusses fabrication techniques such as conductive ink formulation, ink delivery, electroless coating, and fiber integration, along with applications in physiological, physical, and biochemical monitoring. The review concludes by addressing challenges and opportunities, emphasizing the potential of these sensors in revolutionizing medical technology and personalized healthcare.

The use of neural tracers as targeting molecules for drug delivery has been previously established as a novel and efficient method of neural drug delivery. The wheat germ agglutinin-horseradish peroxidase conjugate (WGAHRP) is a common neural tracer, which has been used extensively to decipher neural pathways in vertebrates. It has been widely reported to bind to cell surfaces and be transported in a retrograde fashion (from synapses toward the cell body) via dynein motors along microtubules within axons and transynaptically between neurons. Here we report on the differential binding between WGAHRP and gold-conjugated WGAHRP (AuNP-WGAHRP) to the glycoprotein profiles extracted from two neuronal cell lines and one skeletal muscle cell line, as well as the binding kinetics to heparin. From proteomic analysis of the extracted glycoproteins, we suggest the identity of cell surface glycoproteins involved in the retrograde transport of WGAHRP. This study illuminates the interfacial and molecular interactions of protein-gold conjugates with native ligands and opens the door for the identification of new targets for neural tracing and nervous system-related drug delivery.

Central nervous system (CNS) disorders represent some of the most challenging problems for modern medicine. The complexity of the CNS structure, incomplete understanding of disease, chronic neuroinflammation, and physiological barriers limiting drug delivery all contribute to the difficulty of treating neurological diseases. This review covers the neuroanatomical barriers of the CNS and discusses current treatments, shortcomings of these treatments, recent clinical trials, and opportunities for nanotherapeutic approaches in common CNS disorders. Focus is placed on selected CNS disorders stemming from trauma, neurodegenerative diseases and infectious diseases. The review concludes with a summary and perspectives on the nanotherapeutics development highlighting key challenges and future directions for the field.

Real-time monitoring of public safety, individual health, and environmental conditions relies on accurate continuous data collected by gas sensors, which provide users with cost-effective insights to support informed decision-making. This study presents an innovative approach that simplifies the manufacturing process of nanowire (NW)-based gas sensors by enabling direct electrodeposition of NW crystals on various substrates, such as silicon wafers and polyethylene terephthalate (PET). Copper 7,7,8,8-Tetracyanoquinodimethane (CuTCNQ), a charge-transfer complex, is electrodeposited directly onto photolithographically patterned interdigitated triangle-tip electrodes and functions as a chemiresistive gas sensor that responds to ammonia gas through charge interactions. The sensor's performance can be precisely controlled using electrochemical techniques, allowing for tailored sensitivity across different concentration ranges. To enhance the practical application of this technology, a flexible, near-field communication-based passive tag is developed by integrating the CuTCNQ gas sensor with a flexible printed circuit board. This device enables on-demand ammonia concentration analysis and operates battery-free and wireless through mobile phone scanning. This capability is crucial for wearable or industrial devices and aligns with the increasing demand for robust environmental monitoring solutions. This approach represents a significant step forward in improving both human health and environmental protection through accessible and efficient gas sensing technology.

Abstract Regulating favorable assemblies of metallic atoms in the liquid state provides promise for catalyzing various chemical reactions. Expanding the selection of metallic solvents, especially those with unique properties and low cost, enables access to distinctive fluidic atomic structures on the surface of liquid alloys and offers economic feasibility. Here, Sn solvent, as a low-cost commodity, supports unique atomic assemblies at the interface of molten SnIn0.1034Cu0.0094, which are highly selective for H2 synthesis from hydrocarbons. Atomistic simulations reveal that distinctive adsorption patterns with hexadecane can be established with Cu transiently reaching the interfacial layer, ensuring an energy-favorable route for H2 generation. Experiments with a natural oil as feedstock underscore this approach’s performance, producing 1.2 × 10− 4 mol/min of H2 with 5.0 g of catalyst at ~93.0% selectivity while offering reliable scalability and durability at 260 °C. This work presents an alternative avenue of tuning fluidic atomic structures, broadening the applications of liquid metals.

This paper describes gold-free central nervous system (CNS) drug conjugation with a neural tracing protein, which represents a significant advance toward clinical relevance of the underlying blood-brain barrier (BBB)-bypassing drug delivery nanotechnology. Retrograde neural tracing proteins, such as wheat germ agglutinin (WGA), have been widely used for histochemical staining to map neuronal connections between peripheral nerve terminals and CNS neurons. Here, we demonstrate that WGA on its own can simultaneously function as a nanocarrier, transporter, and targeting agent by its direct chemical conjugation to a CNS drug, dipropylcyclopentyl xanthine (DPCPX), using minimal synthetic steps and reagents without requiring an additional nanoparticle linker. DPCPX, an A1 receptor antagonist, has potential for treating spinal cord injury (SCI)-associated breathing dysfunction. Chemical characterization of the protein-drug nanoconjugate revealed selective conjugation predominantly at arginine residues, with some modifications at lysine residues, providing insights into the stability of protein-aldehyde linkages. We then evaluated the nanoconjugate's in vitro properties, including drug release kinetics, cytotoxicity, and cellular internalization in differentiated NSC-34 cells. Our findings indicate a slow drug release profile, ensuring that the drug remains conjugated to the WGA carrier during retrograde transport and reaches the relevant neural sites in the spinal cord and brainstem, where it can induce a compensatory recovery mechanism via adenosine receptor antagonism.

Electrodeposition is used at the industrial scale to make coatings, membranes, and composites. With better understanding of the nanoscale phenomena associated with the early stage of the process, electrodeposition has potential to be adopted by manufacturers of energy storage devices, advanced electrode materials, fuel cells, carbon dioxide capturing technologies, and advanced sensing electronics. The ability to conduct precise electrochemical measurements using cyclic voltammetry, chronoamperometry, and chronopotentiometry in addition to control of precursor composition and concentration makes electrocrystallization an attractive method to investigate nucleation and early-stage crystal growth. In this article, we review recent findings of nucleation and crystal growth behaviors at the nanoscale, paying close attention to those that deviate from the classical theories in various electrodeposition systems. The review affirms electrodeposition as a valuable method both for gaining new insights into nucleation and crystallization on surfaces and as a low-cost scalable technology for the manufacturing of advanced materials and devices.

Charge-transfer complexes (CTCs), which comprise ordered assemblies of electron acceptor and donor units, represent a mature group of advanced materials. These structures offer unique features, such as intrinsic conductivity, one-dimensional morphology, and tailorable chemistry. To enable the exploitation of CTCs for real-world applications, we investigate CTC nucleation and growth and develop scalable manufacturing methods for their incorporation into electronic systems. In the present work, we combine the unique features of CTCs and liquid metals (LMs) to investigate the galvanic electrocrystallization of tetracyanoquinodimethane complexes with silver (AgTCNQ) and copper (CuTCNQ). The eutectic alloy of gallium and indium (EGaIn) has been shown to be effective in nucleating CTC crystals. EGaIn reduces TCNQ and accumulates metallic precursors at the LM/solution interface via galvanic reduction and stabilization of the metal oxide nanoparticles. This enables the efficient formation and growth of conductive CTC crystals on patterned electronics without the need for an external input. The AgTCNQ wirelike crystals could transfer the autogenous potential of EGaIn, leading to their decoration with Ag nanoparticles. The AgTCNQ crystals grow longer than the CuTCNQ crystals, enabling the interconnection of electronic tracks. This knowledge opens new pathways for scalable CTC crystallization and direct incorporation into electronic systems.

Electric discharge occurs ubiquitously in both natural and engineered systems, where the discharge paths provide critical information. However, control and visualization of discharge patterns is a challenging task. Here arrays of liquid metal marbles, droplets of a gallium-indium eutectic alloy with a copper-doped ZnS luminescent coating, are designed for pixelated visualization of electric discharge paths at optical imaging length-scales. The ZnS particles embed themselves into the surface of liquid metal droplets and are anchored by a self-limiting gallium oxide layer. The operation is achieved by generating spark discharges at inter-marble air gaps and reduced voltage drop across highly conducting liquid metal droplets. By taking advantage of the malleability of soft liquid metal marbles, the dynamic visualization platforms allow the manipulation of discharge path selections in configurable marble arrays and the embedding of artificial defect features. The systems are further integrated for characterizing dynamic changes in granular and soft systems, and for enabling logic computing and information encoded display. This demonstration holds promises for creating new-generation electric discharge-based optoelectronics.

Purpose of this review: Manipulating or re-engineering the damaged human spinal cord to achieve neuro-recovery is one of the foremost challenges of modern science. Addressing the restricted permission of neural cells and topographically organised neural tissue for self-renewal and spontaneous regeneration, respectively, is not straightforward, as exemplified by rare instances of translational success. This review assembles an understanding of advances in nanomedicine for spinal cord injury (SCI) and related clinical indications of relevance to attempts to design, engineer, and target nanotechnologies to multiple molecular networks. Recent findings: Recent research provides a new understanding of the health benefits and regulatory landscape of nanomedicines based on a background of advances in mRNA-based nanocarrier vaccines and quantum dot-based optical imaging. In relation to spinal cord pathology, the extant literature details promising advances in nanoneuropharmacology and regenerative medicine that inform the present understanding of the nanoparticle (NP) biocompatibility–neurotoxicity relationship. In this review, the conceptual bases of nanotechnology and nanomaterial chemistry covering organic and inorganic particles of sizes generally less than 100 nm in diameter will be addressed. Regarding the centrally active nanotechnologies selected for this review, attention is paid to NP physico-chemistry, functionalisation, delivery, biocompatibility, biodistribution, toxicology, and key molecular targets and biological effects intrinsic to and beyond the spinal cord parenchyma. Summary: The advance of nanotechnologies for the treatment of refractory spinal cord pathologies requires an in-depth understanding of neurobiological and topographical principles and a consideration of additional complexities involving the research’s translational and regulatory landscapes.

Exploring and controlling surface tension-driven phenomena in liquid metals may lead to unprecedented possibilities for next-generation microfluidics, electronics, catalysis, and materials synthesis. In pursuit of these goals, the impact of minor constituents within liquid alloys is largely overlooked. Herein, it is showed that the presence of a fraction of solute metals such as tin, bismuth, and zinc in liquid gallium can significantly influence their electrocapillarity and electrochemistry. The instability-driven fractal formation of liquid alloy droplets is investigated with different solutes and reveals the formation of distinctive non-branched droplets, unstable fractals, and stable fractal modes under controlled voltage and alkaline solution conditions. In their individually unique fractal morphology diagrams, different liquid alloys demonstrate significantly shifted voltage thresholds in transition between the three fractal modes, depending on the choice of the solute metal. Surface tension measurements, cycle voltammetry and surface compositional characterizations provide strong evidence that the minor alloy components drastically alter the surface tension, surface electrochemical oxidation, and oxide dissolution processes that govern the droplet deformation and instability dynamics. The findings that minor components are able to regulate liquid alloys' surface tensions, surface element distributions and electrochemical activities offer great promises for harnessing the tunability and functionality of liquid metals.

This state-of-the-art review is geared toward elucidating the molecular understanding of the carbon-based flame-retardant mechanisms for polymers via holistic characterization combining detailed analytical assessments and computational material science. The use of carbon-based flame retardants, which include graphite, graphene, carbon nanotubes (CNTs), carbon dots (CDs), and fullerenes, in their pure and functionalized forms are initially reviewed to evaluate their flame retardancy performance and to determine their elevation of the flammability resistance on various types of polymers. The early transition metal carbides such as MXenes, regarded as next-generation carbon-based flame retardants, are discussed with respect to their superior flame retardancy and multifunctional applications. At the core of this review is the utilization of cutting-edge molecular dynamics (MD) simulations which sets a precedence of an alternative bottom-up approach to fill the knowledge gap through insights into the thermal resisting process of the carbon-based flame retardants, such as the formation of carbonaceous char and intermediate chemical reactions offered by the unique carbon bonding arrangements and microscopic in-situ architectures. Combining MD simulations with detailed experimental assessments and characterization, a more targeted development as well as a systematic material synthesis framework can be realized for the future development of advanced flame-retardant polymers.

Single-atom electrocatalysts (SACs) are a class of promising materials for driving electrochemical energy conversion reactions due to their intrinsic advantages, including maximum metal utilization, well-defined active structures, and strong interface effects. However, SACs have not reached full commercialization for broad industrial applications. This review summarizes recent research achievements in the design of SACs for crucial electrocatalytic reactions on their active sites, coordination, and substrates, as well as the synthesis methods. The key challenges facing SACs in activity, selectivity, stability, and scalability, are highlighted. Furthermore, it is pointed out the new strategies to address these challenges including increasing intrinsic activity of metal sites, enhancing the utilization of metal sites, improving the stability, optimizing the local environment, developing new fabrication techniques, leveraging insights from theoretical studies, and expanding potential applications. Finally, the views are offered on the future direction of single-atom electrocatalysis toward commercialization.

The use of liquid gallium as a solvent for catalytic reactions has enabled access to well-dispersed metal atoms configurations, leading to unique catalytic phenomena, including activation of neighbouring liquid atoms and mobility-induced activity enhancement. To gain mechanistic insights into liquid metal catalysts, here we introduce a GaSn0.029Ni0.023 liquid alloy for selective propylene synthesis from decane. Owing to their mobility, dispersed atoms in a Ga matrix generate configurations where interfacial Sn and Ni atoms allow for critical alignments of reactants and intermediates. Computational modelling, corroborated by experimental analyses, suggests a particular reaction mechanism by which Sn protrudes from the interface and an adjacent Ni, below the interfacial layer, aligns precisely with a decane molecule, facilitating propylene production. We then apply this reaction pathway to canola oil, attaining a propylene selectivity of ~94.5%. Our results offer a mechanistic interpretation of liquid metal catalysts with an eye to potential practical applications of this technology.

Tumor penetration of nanoparticles is crucial in nanomedicine, but the mechanisms of tumor penetration are poorly understood. This work presents a multidimensional, quantitative approach to investigate the tissue penetration behavior of nanoparticles, with focuses on the particle size effect on penetration pathways, in an MDA-MB-231 tumor spheroid model using a combination of spectrometry, microscopy, and synchrotron beamline techniques. Quasi-spherical gold nanoparticles of different sizes are synthesized and incubated with 2D and 3D MDA-MB-231 cells and spheroids with or without an energy-dependent cell uptake inhibitor. The distribution and penetration pathways of nanoparticles in spheroids are visualized and quantified by inductively coupled plasma mass spectrometry, two-photon microscopy, and synchrotron X-ray fluorescence microscopy. The results reveal that 15 nm nanoparticles penetrate spheroids mainly through an energy-independent transcellular pathway, while 60 nm nanoparticles penetrate primarily through an energy-dependent transcellular pathway. Meanwhile, 22 nm nanoparticles penetrate through both transcellular and paracellular pathways and they demonstrate the greatest penetration ability in comparison to other two sizes. The multidimensional analytical methodology developed through this work offers a generalizable approach to quantitatively study the tissue penetration of nanoparticles, and the results provide important insights into the designs of nanoparticles with high accumulation at a target site.

AbstractElectrocrystallization is a promising method for controlled charge‐transfer complex (CTC) deposition on microfabricated electrodes for gas sensing applications. However, there remains a gap in our understanding of CTC electrodeposition. In this study, we focus on investigating the electrocrystallization of cobalt tetracyanoquinodimethane (Co‐TCNQ) on a microdisk electrode to elucidate and control the process. Leveraging the microelectrode technique, we conduct steady‐state measurements to observe nucleation and crystal growth dynamics, particularly in the early stages of electrocrystallization. We use cyclic voltammetry and chronoamperometry to examine Co‐TCNQ electrocrystallization under various electrolytic conditions. We identify electrocrystallization kinetics, ranging from electrokinetic to diffusion‐limited growth, governing the nucleation and growth of Co‐TCNQ crystals. Notably, we pinpoint the applied overpotential and precursor concentration range necessary for a single nucleation site on the microelectrode. Moreover, we demonstrate control over crystal orientation and morphology. Our findings reveal a nonclassical growth pathway for Co‐TCNQ crystals characterized by oriented attachment of small crystallites along the conductive long axis. Importantly, electrodeposited Co‐TCNQ on patterned microelectrodes exhibits selective sensing capabilities for nitrogen dioxide gas. Overall, this study sheds light on CTC electrodeposition through a proof‐of‐concept demonstration involving Co‐TCNQ electrodeposition on microelectrodes, presenting potential applications across diverse materials.