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Biological and synthetic molecular motors, fueled by various physical and chemical means, can perform asymmetric linear and rotary motions that are inherently related to their asymmetric shapes. Here, we describe silver-organic micro-complexes of random shapes that exhibit macroscopic unidirectional rotation on water surface through the asymmetric release of cinchonine or cinchonidine chiral molecules from their crystallites asymmetrically adsorbed on the complex surfaces. Computational modeling indicates that the motor rotation is driven by a pH-controlled asymmetric jet-like Coulombic ejection of chiral molecules upon their protonation in water. The motor is capable of towing very large cargo, and its rotation can be accelerated by adding reducing agents to the water. ‘Molecular motors, fuelled by various physical and chemical means, can perform asymmetric linear and rotary motions that are inherently related to their asymmetric shapes. Here, the authors describe silver-organic micro-complexes of random shapes that exhibit macroscopic unidirectional rotation on water surface through the asymmetric release of cinchonine or cinchonidine chiral molecules.

Biofilms are responsible for about considerable amounts of cases of bacterial infections in humans. They are considered a major threat to transplant and chronic wounds patients due to their highly resistant nature against antibacterial materials and due to the limited types of techniques that can be applied to remove them. Here we demonstrate a successful in-situ bio-assisted synthesis of dual functionality nanoparticles composed of Silver and Gold. This is done using a jellyfish-based scaffold, an antibacterial material as the templating host in the synthesis. We further explore the scaffold’s antibacterial and photothermal properties against various gram-negative and positive model bacteria with and without photo-induced heating at the Near-IR regime. We show that when the scaffold is loaded with these bimetallic nanoparticles, it exhibits dual functionality: Its photothermal capabilities help to disrupt and remove bacterial colonies and mature biofilms, and its antibacterial properties prevent the regrowth of new biofilms. Graphical Abstract

Anisotropic subwavelength particles uniquely combine the strong, tunable response of nanostructures with the exotic properties of anisotropic materials, enabling diverse applications in photonics, biomedicine, and magnetism. Anisotropic particles are also prevalent in systems such as ice grains, liquid crystal droplets, and ferromagnetic particles. Nanostructures supporting hyperbolic phonon‐polaritons hold significant promise for infrared applications due to their strong anisotropic optical response. However, previous experiments primarily explored isotropic or uniaxial nanostructures, with eigenmode theories limited to isotropic particles, restricting the understanding and applicability of anisotropic particles. Here, localized phonon resonances in the mid‐infrared spectral region in biaxial nanoparticles with three distinct axial permittivities are observed. Using a novel femtosecond‐pulsed laser ablation method, α‐molybdenum trioxide nanoparticles are synthesized with tunable, high‐Q‐factor mid‐infrared resonances. Additionally, a comprehensive theoretical framework is derived for anisotropic nanoparticles, which aligns exceptionally well with the experimental results. The findings uncover the physics of polaritons in biaxial nanoparticles, including both fundamental and higher‐order modes, paralleling the significant shift in isotropic plasmon‐polariton research toward nanostructure resonators in the visible range. The research paves the way for a new generation of tunable, multispectral, anisotropic, and directional mid‐infrared nanoresonators, opening new possibilities for mid‐infrared imaging, sensitive photonic devices, and biomarkers. Biaxial α‐MoO3 nanoparticles exhibit tunable, high‐Q mid‐infrared resonances driven by localized phonon polaritons. Combining a novel synthesis method, hyperspectral near‐field imaging and a unified theoretical analysis, this work reveals eigenmodes and resonance conditions in biaxial particles. These findings unlock the potential for a new generation of directional, multispectral mid‐IR nanophotonics, with broad implications for imaging, sensing, and magnetostatics.

Molecule–plasmon interactions have been shown to have a definite role in light propagation through optical microcavities due to strong coupling between molecular excitations and surface plasmons. This coupling can lead to macroscopic extended coherent states exhibiting increment in temporal and spatial coherency and a large Rabi splitting. Here, we demonstrate spatial modulation of light transmission through a single microcavity patterned on a free-standing Au film, strongly coupled to one of the most efficient energy transfer photosynthetic proteins in nature, photosystem I. Here we observe a clear correlation between the appearance of spatial modulation of light and molecular photon absorption, accompanied by a 13-fold enhancement in light transmission and the emergence of a distinct electromagnetic standing wave pattern in the cavity. This study provides the path for engineering various types of bio-photonic devices based on the vast diversity of biological molecules in nature. The interaction between light and molecules can lead to hybrid quantum-physical states of light and matter. Here, the authors demonstrate one such effect, spatial modulation of light, with the protein photosystem I as a first demonstration of this quantum effect with such a biological molecule.

We report an efficient, high-yield method for synthesizing dumbbell-shaped conjugates composed of gold nanoparticles (AuNPs) connected by double-stranded (ds) DNA. The dsDNA, bearing terminal thiol groups, was covalently attached to two AuNPs to form uniform constructs comprising either 15 nm or 25 nm particles bridged by 38 base pairs (bp) or 100 bp dsDNA. The dumbbells were purified by gel electrophoresis and exhibited high stability, remaining intact for several days in pure water or buffers at ambient temperature. Deposition onto solid substrates followed by drying, however, led to their partial structural collapse. TEM imaging showed that deposition on carbon grids typically yielded dumbbell structures with interparticle gaps of only 1–2 nm, suggesting that the dsDNA bridge contracts during deposition and drying. However, deposition on polylysine-coated mica for AFM imaging preserved the native geometry, with the gaps consistent with the expected DNA length. Our results reveal that deposition significantly affects the structure and integrity of dsDNA bridges in dumbbell constructs, highlighting the importance of appropriate substrate and surface coating selection for reliable characterization of DNA properties in dried dumbbells.

Here, we demonstrate through AFM imaging and CD spectroscopy that the binding of silver ions (Ag+) to poly(dGdC), a double-stranded (ds) DNA composed of two identical repeating strands, at a stoichiometry of one Ag+ per GC base pair induces a one-base shift of one strand relative to the other. This results in a ds nucleic acid-Ag+ conjugate consisting of alternating CC and GG base pairs coordinated by silver ions. The proposed organization of the conjugate is supported by the results of our Quantum Mechanical (QM) and Molecular Mechanics (MMs) calculations. The reduction of Ag+ ions followed by the partial oxidation of silver atoms yields a highly fluorescent conjugate emitting at 720 nm. This fluorescent behavior in conjugates of long, repetitive ds DNA (thousands of base pairs) with silver has never been demonstrated before. We propose that the poly(dGdC)–Ag conjugate functions as a dynamic system, comprising various small clusters embedded within the DNA and interacting with one another through energy transfer. This hypothesis is supported by the results of our QM and MMs calculations. Additionally, these DNA–silver conjugates, comprising silver nanoclusters, may possess conductive properties, making them potential candidates for use as nanowires in nanodevices and nanosensors.

Inspired by nature, green chemistry uses various biomolecules, such as proteins, as reducing agents to synthesize metallic nanostructures. This methodology provides an alternative route to conventional harsh synthetic processes, which include polluting chemicals. Tuning the resulting nanostructure properties, such as their size and shape, is challenging as the exact mechanism involved in their formation is still not well understood. This work reports a well-controlled method to program gold nanostructures' shape, size, and aggregation state using only one protein type, mucin, as a reduction and capping material in a one-pot bio-assisted reaction. Using mucin as a gold reduction template while varying its tertiary structure via the pH of the synthesis, we demonstrate that spherical, coral-shaped, and hexagonal gold crystals can be obtained and that the size can be tuned over three orders of magnitude. This is achieved by leveraging the protein's intrinsic reducing properties and pH-induced conformational changes. The systematic study of the reaction kinetics and growth steps developed here provides an understanding of the mechanism behind this phenomenon. We further show that the prepared gold nanostructures exhibit tunable photothermal properties that can be optimized for various hyperthermia-induced antibacterial applications.

Using hyperspectral measurements, J‐aggregate nanorods of porphyrin molecules embedded in plasmonic Au nanoparticles arrays are studied. Measurements of J‐aggregate nanorods that cross onto a plasmonic array exhibit a shift in their absorption peak, and display weak coupling properties only for the embedded part. Furthermore, a significant thickness‐dependent redshift in the plasmonic resonance for the J‐aggregate clusters is observed. Such redshift is also dependent on the ratio of J‐aggregate in the plasmonic dipole interaction area, reaching values of up to 120 meV for ≈40% coverage. In addition, for large clusters of J‐aggregates, the plasmonic spectrum shows coupling behavior between the systems indicated by a small Rabi splitting. The findings are validated by a quasi‐static model based on the change of the dielectric environment around the embedded nanoparticles. Using the model, the fraction of embedding J‐aggregates in the plasmonic interaction area is correlated with the change in plasmonic resonance peak. These results offer insight into the coupled nature of molecular emitters in supramolecular structures and their interaction with plasmonic nanoparticles and can lead to new types of sensitive optical detectors based on these interactions. Rod‐shaped porphyrin J‐aggregates are deposited on plasmonic Au nanoparticle, and studied by hyperspectral microscopy with K‐means analysis. Weak coupling for single J‐aggregates on Au array is observed. Clusters of rods cause a large redshift of the plasmonic peak. Developed analytical model explains the redshift and can predict the ratio of J‐aggregates to the air around plasmonic nanoparticles from the spectrum.

Multi-hierarchical self-assembly （MHSA） is a key process responsible for the spontaneous formation of many complex structures. However, because of the complexity of the process, the underlying mechanism remains largely unclear. Thus, a deeper understanding of MHSA is required, especially for the preparation of MHSA systems via bottom-up methodologies. We show here, experimentally and theoretically, that the complex-formation MHSA of peptide nanotube films can be controlled solely by manipulating the experimental parameter of humidity. Furthermore, we identify growth-front nucleation （GFN; the formation of new grains at the perimeter） as the physical background for the observed morphological transitions by correlating experimental observations with phase-field modeling of the morphological evolution. Our findings indicate a simple way to control multi-hierarchical morphologies, crucial for the employment of bottom-up techniques in constructing complex structures for practical applications.

Background One of the goals in the field of structural DNA nanotechnology is the use of DNA to build up 2- and 3-D nanostructures. The research in this field is motivated by the remarkable structural features of DNA as well as by its unique and reversible recognition properties. Nucleic acids can be used alone as the skeleton of a broad range of periodic nanopatterns and nanoobjects and in addition, DNA can serve as a linker or template to form DNA-hybrid structures with other materials. This approach can be used for the development of new detection strategies as well as nanoelectronic structures and devices. Method Here we present a new method for the generation of unprecedented all-organic conjugated-polymer nanoparticle networks guided by DNA, based on a hierarchical self-assembly process. First, microphase separation of amphiphilic block copolymers induced the formation of spherical nanoobjects. As a second ordering concept, DNA base pairing has been employed for the controlled spatial definition of the conjugated-polymer particles within the bulk material. These networks offer the flexibility and the diversity of soft polymeric materials. Thus, simple chemical methodologies could be applied in order to tune the network's electrical, optical and mechanical properties. Results and conclusions One- two- and three-dimensional networks have been successfully formed. Common to all morphologies is the integrity of the micelles consisting of DNA block copolymer (DBC), which creates an all-organic engineered network.