Janus Nanoparticles Research Articles

Amphiphilic Janus nanoparticle enabled aqueous two-phase flotation for separation and enrichment of rosmarinic acid from perilla leaves

ABSTRACT Uncrosslinked pressure‐sensitive adhesives (PSAs) typically suffer from low cohesive strength and high cold flow, which significantly limit their practical applications. This study proposed a strategy to improve the performance of uncrosslinked pressure‐sensitive adhesives by using a Janus‐nanoparticle‐toughened three‐dimensional network structure. Specifically, reactive Janus nanoparticles (JPs) were designed and reinforced polyisobutylene/acrylic polymer semi‐interpenetrating network (Semi‐IPN) PSAs via a combination of free radical‐initiated cross‐linking and chain entanglement. The morphological structure, mechanical performance, adhesion properties, and rheological behavior of the Semi‐IPN PSAs were systematically investigated. The results demonstrated that the shear strength and peel strength of PSAs that retained the unique properties of polyisobutylene (PIB) increased by 362% and 301%, respectively. In addition, although the initial tack dropped by two grades, the cold flow was significantly reduced. This multiple interaction between the reactive JPs and the PSAs matrix substantially improves the performance of uncrosslinked PSAs. This offers valuable insights for the rational design of high‐performance adhesive systems.

A novel topical delivery of biphasic Janus nanoparticles loaded with miconazole nitrate and berberine hydrochloride for antifungal therapy against Candida albicans

Simultaneous photo-magnetic dual hyperthermia combined with radiotherapy enhanced by snowman‑shaped Janus nanoparticles in CT26 colon cancer model

Valence EELS study of the composition of a liquid phase in a Janus Sn-Ge nanoparticle over a temperature range of 250-750 °C.

Amphiphilic Janus nanoparticles for effective foam fractionation of perfluorooctanoic acid (PFOA): Effect of modifier type.

Smart chemosensors based on stimuli-chromic polymer nanoparticles modified with oxazolidine derivatives have been developed in recent years, making them remarkable for the detection of pH, metal ions, and polarity and for the visualization of latent fingerprints (LFPs). However, the design of a dual-mode or all-in-one sensor for multiple applications, especially fluorimetric or colorimetric detection of pH and in situ visualization of LFPs, is the most important challenge. In this study, three-arm star-shaped block copolymers were synthesized via sequential atom-transfer radical polymerization (ATRP) of methyl methacrylate (MMA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) using a core-first strategy. The degree of polymerization (DPn) of the poly(methyl methacrylate) (PMMA) block is 17.5, and the DPn of the poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) block is approximately 17; the polydispersity index (Đ) is about 1.19. The self-assembly of the 3-ArmPMMA-b-PDMAEMA sample resulted in different anisotropic morphologies or Janus nanoparticles, such as snowman, dumbbell-like, multilobe, vesicular, and hollow spheres with regular concavities on the surface, and a narrow particle size distribution. The prepared halochromic nanoparticles containing two oxazolidine derivatives (OXOH and OXNM) were used to detect and monitor pH in the wide range of 1-14 by colorimetric and fluorimetric signals. The main advantage of the developed pH sensor is the high colloidal stability of 3-ArmPMMA-b-PDMAEMA nanoparticles in highly acidic (pH < 3) and alkaline (pH > 10) media. In addition, the halochromic nanoparticles were used as a spray for the in situ visualization of LFPs using aggregation-induced emission (AIE) and fluorescence imaging as a fast strategy for forensic investigations at crime scenes, crime science, and medical diagnostics. The visualized LFPs displayed red emission with high intensity and minimum background emission, and three identification levels were successfully achieved. The prepared halochromic nanoparticles can be introduced as a probe for the detection of pH (1-14) and the in situ visualization of LFPs by spraying.

The ability to control the morphology of organic semiconductor nanoparticles is of paramount importance for applications in organic photovoltaics, photocatalysis, and photo-triggered biological applications. In this paper, we demonstrate that nanoprecipitation is a powerful technique to provide a variety of morphologies in binary blends of organic semiconductors. By investigating seven different donor : acceptor couples we demonstrate that the resulting morphology is primarily governed by the interfacial tension between the two photo-active components. The structure of the particles is also influenced by the interactions between the medium and the materials. Indeed, we show that the medium should not be considered solely as water; rather, the surfactant employed and the organic solvent in which the materials are dissolved also play crucial roles. By manipulating these parameters, P3HT : PC61BM nanoparticles were produced via nanoprecipitation, exhibiting either intermixed, Janus, or core-shell morphologies depending on the dispersive medium. Cryo-TEM and STEM-EDX were utilized to image the internal structure of the particles for couples involving PC61BM and non-fullerene acceptors (NFA) such as Y6 and a polymer P(DTS-DAP). The increased surface tension between the donors and PC61BM generally results in the formation of Janus nanoparticles. Conversely, the NFAs used in this study exhibit a higher compatibility with the donor, thereby promoting in some cases an intermixed structure.

Janus nanoparticles (JNPs), with their spatially distinct chemical domains, represent a powerful platform for engineering multifunctional interfaces at the nanoscale. This review explores the chemistry that governs their design—focusing on how surface anisotropy enables orthogonal reactivity, directional assembly, and environment-specific interactions in biological systems. We analyze key synthetic approaches such as interfacial polymerization, Pickering emulsions, and surface-directed phase separation, highlighting how chemical asymmetry can be tuned for targeted delivery, molecular imaging, and biosensing. Beyond summarizing current strategies, we propose a framework connecting interfacial chemistry to functional output, offering insight into how Janus design principles can be chemically programmed to address limitations in precision therapeutics and diagnostics. We also outline future challenges in scalability, ligand compatibility, and interface predictability, advocating for a chemistry-first approach to next-generation JNP systems. By linking molecular design to functional behavior, this review aims to catalyze innovation in chemically tailored nanomaterials for biomedical and beyond.

Abstract Janus nanoparticles (JNPs) are distinguished by their dual-faced structure, where each side exhibits distinct physical, chemical, or functional properties. This asymmetry enables JNPs to perform multiple roles simultaneously, making them highly versatile for drug delivery, biosensing, bioimaging, and environmental remediation applications. Synthesis methods such as masking, self-assembly, phase separation, and selective surface modification allow precise control over JNP morphology and functionality, enabling tailored properties like amphiphilic surfaces, magnetic or fluorescent domains, and hybrid compositions. Characterization tools such as SEM, TEM, and XRD mapping are crucial for understanding their structural and compositional attributes, facilitating optimization for specific applications. In biomedicine, JNPs show promise in targeted drug delivery, bioimaging, and theranostics, combining diagnostic and therapeutic capabilities. In environmental engineering, they are effective in water decontamination and removing heavy metals from contaminated water. This review provides a comprehensive overview of synthesis strategies, characterization techniques, applications, and critical analysis of JNPs, highlighting recent advancements and future directions to overcome the challenges.

Nanoscales that mimic natural cascade catalytic reactions through simple procedures, demonstrating high efficiency, have attracted extensive interest in the antibacterial field. However, the rational design of nanostructures and the improvement of their catalytic efficiency remain challenging. Herein, spindle-shaped Ni-Au Janus nanocomposites (JANs) are synthesized with asymmetric catalytic duality and NIR-responsive photothermal activation. The spatially segregated Au and Ni domains synergistically drive a catalytic cascade: the Au domain exhibits glucose oxidase-like activity to self-supply H2O2, while the Ni domain functions as a peroxidase to convert H2O2 into cytotoxic ·OH. Notably, NIR irradiation amplifies catalytic activity by promoting hot electron migration across Ni-Au heterojunctions, reducing the Km value of H2O2 from 13.29 to 5.54 mm, and increasing Vmax by ≈1.3-fold. Coupled with the inherent bacterial binding capacity of Ni facet, this synergistic cascade facilitates in situ ·OH production, enhancing broad-spectrum antimicrobial properties (82.75% against Escherichia coli and 83.26% against Staphylococcus aureus). The bactericidal effect is verified in vivo and maintained good cytocompatibility. These findings demonstrate that the antibacterial efficacy can be enhanced through the precise design of Janus structures and the physicochemical properties of the nanoplatform, paving the way for a novel cascade catalytic strategy in bacterial disinfection.

Abstract Biofilm‐associated refractory pneumonia represents a growing clinical challenge, where the protective extracellular matrix not only confers drug resistance but also promotes persistent infections. While topologically structured physical bactericidal systems show potential for biofilm disruption, their reliance on passive diffusion limits penetration efficiency, and biofilm regeneration following treatment remains problematic. Inspired by phage invasion mechanisms, a biohybrid nanomotor integrating sono‐sensitive antibiotics is developed for combating multidrug‐resistant Klebsiella pneumonia (MDR‐KPN)‐induced lung infections. The asymmetric heterostructured nanomotor consists of hollow mesoporous Prussian blue‐lomefloxacin/mesoporous CuxO (CuO/Cu2O composite) Janus nanoparticle (HP‐L/MCu JNPs), which can actively target and dismantle biofilms through integrated mechanical and chemical action. The innovative design of nanomotor leverages two complementary functionalities: CuxO nanospheres provide autonomous propulsion for mechanical biofilm penetration, and the Prussian blue subunit enables ultrasound‐triggered antibiotic release; meanwhile, ultrasound‐activated antibiotics generate cytotoxic singlet oxygen (1O2) that induces irreparable DNA damage in surviving bacteria. Transcriptomic analysis confirms this combined mechanical‐chemical action effectively disperses biofilms while preventing bacterial recovery. In vivo validation demonstrates the therapeutic potential of this biomimetic strategy, which merges physical destruction with catalytic chemistry to overcome biofilm‐associated treatment resistance. This approach establishes a new paradigm for addressing persistent bacterial infections through integrated nanoarchitectonics.

Janus nanoparticles (JNPs) represent one of the most complex nanoparticles, and achieving precise control over their synthesis remains a significant challenge. Here, we explore gold-silver sulfide (Au-Ag₂S) JNPs for targeted anticancer and antibacterial therapies. Au-Ag₂S JNPs were synthesized and characterized using TEM, HRTEM, XRD, EDS, and XPS, confirming their distinct dimeric structure with Au and Ag₂S components. Surface modification with DSPE-PEG and folic acid (FA) enhanced stability and enabled targeted delivery to cancer cells, resulting in AADF JNPs. AADF JNPs exhibited strong NIR-II emission, ideal for in vivo imaging and photothermal therapy (PTT). In vitro studies demonstrated high biocompatibility and enhanced cellular uptake in 4T1 cancer cells compared to non-targeted JNPs. Upon laser irradiation, AADF JNPs effectively reduced 4T1 cell viability, demonstrating their phototherapeutic effect. Furthermore, AADF JNPs exhibited potent antibacterial activity against Escherichia coli and Staphylococcus aureus under NIR irradiation, it achieved 78% tumor cell killing and 99% bacterial eradication. These findings highlight the potential of AADF JNPs as a promising solution for targeted cancer and bacterial infection treatments.

Emulsion self-template induced organic-inorganic hybrid Janus nanoparticles towards constructing self-healing self-reporting anticorrosive functional coating

In this work, we investigate the thermophoresis of Janus nanoparticles in liquids through molecular dynamics simulations. Thermophoretic forces acting on cylindrical Janus nanoparticles are calculated through MD simulations by varying the particle size, the heterogenous surface energies, and the mean temperature of the fluid. It is found that a transition from negative thermophoresis to positive thermophoresis occurs when these parameters are varied. The surface energies and mean temperature affect both the magnitude of the thermophoretic force and the transition from negative to positive thermophoresis. However, the particle size only influences the magnitude of the thermophoretic force, not the transition from negative to positive thermophoresis. Contributions of the total energy and pressure of fluid molecules are studied by evaluating the excess enthalpy density around the particle. A general scaling relationship for the thermophoretic force is developed using dimensionless numbers. This work advances the understanding of the thermophoresis of Janus nanoparticles and offers theoretical support for manipulating Janus nanoparticles in liquids by temperature gradients.

The interplay between nanoparticle (NP) interaction anisotropy and nanoscale confinement gives rise to diverse self-assembly behaviors and the resulting macroscopic thermal properties. In this study, we use molecular dynamics (MD) simulations to explore the relationship between the structural and thermal properties of nanofluids confined in nanoscale channels. The chemical surface design of NPs alters the dependence of thermal conductivity on channel width: homogeneous hydrophilic (HI) NPs maintain thermal conductivity by forming a stable adsorption layer around dispersed NPs, whereas diblock Janus NPs exhibit clustering effects due to interaction anisotropy. This clustering weakens adsorption layers, reducing thermal conductivity even under weak confinement. Under strong confinement, solvent molecules form more pronounced structured layers near the walls; however, NPs disrupt this ordering, resulting in lower thermal conductivity than in a confined purely solvent system. Diblock Janus NPs, in particular, disrupt these layers more due to their clustering, further hindering thermal conductivity. Although both NP types exhibit reduced Brownian motion as channel width decreases, we conclude that it does not significantly affect the thermal conductivity of nanofluids. For instance, Janus NPs, which exhibit greater Brownian motion in wider channels, still show lower thermal conductivity than HI NPs. While HI NPs form stable adsorption layers that enhance thermal transport, Janus NPs tend to self-assemble into micelles, weakening the adsorption layer and further reducing thermal conductivity. Our study provides molecular insight into the relationship between NP dynamics, surface properties, and adsorption layers in determining the thermal conductivity of confined nanofluids.

Natural antimicrobials synergistically coupled with nanomotors: An innovative strategy for biofilm eradication.

In order to improve oil recovery efficiency in low-permeability reservoirs, this study developed amphiphilic Janus-SiO2 nanoparticles to prepare polymer gel microspheres for enhanced oil recovery (EOR). Firstly, Janus-SiO2 nanoparticles were synthesized via surface modification using (3-aminopropyl)triethoxysilane and α-bromoisobutyryl bromide. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) characterization confirmed the successful grafting of amino and styrene chains, with the particle size increasing from 23.8 nm to 32.9 nm while maintaining good dispersion stability. The Janus nanoparticles exhibited high interfacial activity, reducing the oil-water interfacial tension to 0.095 mN/m and converting the rock surface wettability from oil-wet (15.4°) to strongly water-wet (120.6°), thereby significantly enhancing the oil stripping efficiency. Then, polymer gel microspheres were prepared by reversed-phase emulsion polymerization using Janus-SiO2 nanoparticles as emulsifiers. When the concentration range of nanoparticles was 0.1-0.5 wt%, the particle size range of polymer gel microspheres was 316.4-562.7 nm. Polymer gel microspheres prepared with a high concentration of Janus-SiO2 nanoparticles can ensure the moderate swelling capacity of the particles under high-temperature and high-salinity conditions. At the same time, it can also improve the mechanical strength and shear resistance of the microspheres. Core displacement experiments confirmed the dual synergistic effect of this system. Polymer gel microspheres can effectively plug high-permeability zones and improve sweep volume, while Janus-SiO2 nanoparticles enhance oil displacement efficiency. Ultimately, this system achieved an incremental oil recovery of 19.72%, exceeding that of conventional polymer microsphere systems by more than 5.96%. The proposed method provides a promising strategy for improving oil recovery in low-permeability heterogeneous reservoir development.

Abstract Multicompartment polymer nanoparticles, such as two-faced Janus and patchy particles composed of distinct chemical features, have received increasing attention because of their utility for interfacial and self-assembly applications originating from the asymmetric particulate structure. This review discusses such nanoparticles in several tens of nanometers produced by controlled polymerizations, which enable scalable synthesis with control of molecular characteristics. We focus on miktoarm core cross-linked star polymers and Janus core–shell bottlebrush polymers as 0D and 1D anisotropic nano-objects containing a discrete core and a compartmentalized shell. We discuss how controlled polymerizations can covalently build such complex architectures with spatial control of the constituting segments to achieve intramolecular segregation. Then, we collectively view their distinct interfacial and self-assembling behaviors reported in the literature from experimental and simulation perspectives. Graphic abstract In this review, we discuss synthetic approaches to compartmentalized core cross-linked star and bottlebrush copolymers composed of chemically distinct segments and their self-assembly/interfacial behavior as Janus and patchy soft nanoparticles with spherical and elongated geometries.

Accurate detection of circulating tumor cells (CTCs) remains a critical challenge in clinical oncology due to limitations in sensitivity, cost-effectiveness, and operational complexity. In this study, a wireless cytosensor is developed, leveraging a bionic dandelion isothermal amplification system (BDIAS) and wireless lateral flow immunoassay (LFIA) technology. The BDIAS, composed of a hexapod DNAwalker, nonlinear DNA self-assembly technology and an asymmetric carrier, and AuFe Janus nanoparticles (AuFe JNPs) with high signal probe loading efficiency, exhibits remarkable amplification efficiency. Compared with traditional isothermal amplification systems (TIASs), the BDIAS demonstrated a 6.72-fold enhancement in amplification efficiency. The wireless LFIA analysis technology, integrating a wireless fluorescence strip analyzer and smartphone, enables rapid and precise detection of fluorescence signals on the test line (T-line) of the LFIA strip, with interpretation of the results completed within one second. The wireless cytosensor, based on the synergistic integration of BDIAS and wireless LFIA technology, achieves an ultralow detection limit of 1.58 cells/mL while exhibiting remarkable operational simplicity. Furthermore, it demonstrates superior specificity and reproducibility. Notably, the proposed wireless cytosensor is capable of accurately detecting CTCs in whole-blood samples and exhibits robust anti-interference capabilities, rendering it highly promising for clinical applications.