Chiral-Induced Surface-Enhanced Raman Optical Activity on a Single-Particle Substrate.

Surface-enhanced Raman optical activity (SEROA) is a promising method for analyzing chiral molecules' molecular chirality and structural changes. However, conventional SEROA measurements face challenges related to substrate stability, signal uniformity, and interference from electronic circular dichroism (ECD). Therefore, in this study, we present a uniform and stable substrate for SEROA measurements by utilizing Au nanoparticles on the Au nanofilm structure to confine hotspots to the film-particle junctions and minimize ECD interference. This method also uses the induction of chirality from chiral molecules to achiral molecules to overcome the limitation of chiral molecules in SEROA measurements, specifically their lower signal efficiency. Successful chirality transfer is demonstrated through distinguishable SEROA signals when the l/d-alanine mixture is present. Enantiomeric discrimination of different l/d-alanine ratios was achieved with linear responses in the circular intensity difference (CID). Altogether, the proposed chiral-induced SEROA on the AuNP_on_AuNF substrate shows promising potential for detecting and characterizing structural changes in biomolecules, thus making it a valuable tool for various research applications.

Investigating chiral morphogenesis of gold using generative cellular automata.

Homochirality is an important feature in biological systems and occurs even in inorganic nanoparticles. However, the mechanism of chirality formation and the key steps during growth are not fully understood. Here we identify two distinguishable pathways from achiral to chiral morphologies in gold nanoparticles by training an artificial neural network of cellular automata according to experimental results. We find that the chirality is initially determined by the nature of the asymmetric growth along the boundaries of enantiomeric high-index planes. The deep learning-based interpretation of chiral morphogenesis provides a theoretical understanding but also allows us to predict an unprecedented crossover pathway and the resulting morphology.

Spin angular momentum-encoded single-photon emitters in a chiral nanoparticle-coupled WSe2 monolayer.

Spin angular momentum (SAM)-encoded single-photon emitters, also known as circularly polarized single photons, are basic building blocks for the advancement of chiral quantum optics and cryptography. Despite substantial efforts such as coupling quantum emitters to grating-like optical metasurfaces and applying intense magnetic fields, it remains challenging to generate circularly polarized single photons from a subwavelength-scale nanostructure in the absence of a magnetic field. Here, we demonstrate single-photon emitters encoded with SAM in a strained WSe2 monolayer coupled with chiral plasmonic gold nanoparticles. Single-photon emissions were observed at the nanoparticle position, exhibiting photon antibunching behavior with a g(2)(0) value of ~0.3 and circular polarization properties with a slight preference for left-circular polarization. Specifically, the measured Stokes parameters confirmed strong circular polarization characteristics, in contrast to emitters coupled with achiral gold nanocubes. Therefore, this work provides potential insights to make SAM-encoded single-photon emitters and understand the interaction of plasmonic dipoles and single photons, facilitating the development of chiral quantum optics.

Tuning the CO2 Reduction Selectivity of an Immobilized Molecular Ag Complex beyond CO.

The electrochemical reduction of carbon dioxide (CO2) to produce fuels and chemicals has garnered significant attention. However, achieving control over the selectivity of the resulting products remains a challenging task, particularly within molecular systems. In this study, we employed a molecular silver complex immobilized on graphitized mesoporous carbon (GMC) as a catalyst for converting CO2 into CO, achieving an impressive selectivity of over 90% at -1.05 V vs RHE. Notably, the newly formed silver nanoparticles emerged as the active sites responsible for this high CO selectivity rather than the molecular system. Intriguingly, the introduction of copper ions into the restructured Ag-nanoparticle-decorated carbon altered the product selectivity. At -1.1 V vs RHE in 0.1 M KCl, we achieved a high C2 selectivity of 75%. Furthermore, not only the Ag-Cu bimetallic nanoparticle but also the small-sized Ag-Cu nanocluster decorated over GMC was proposed as active sites during catalytic reactions. Our straightforward approach offers valuable insights for fine-tuning the product selectivity of immobilized molecular systems, extending beyond C1 products.

Kink-Controlled Gold Nanoparticles for Electrochemical Glucose Oxidation.

Enzymes in nature efficiently catalyze chiral organic molecules by elaborately tuning the geometrical arrangement of atoms in the active site. However, enantioselective oxidation of organic molecules by heterogeneous electrocatalysts is challenging because of the difficulty in controlling the asymmetric structures of the active sites on the electrodes. Here, we show that the distribution of chiral kink atoms on high-index facets can be precisely manipulated even on single gold nanoparticles; and this enabled stereoselective oxidation of hydroxyl groups on various sugar molecules. We characterized the crystallographic orientation and the density of kink atoms and investigated their specific interactions with the glucose molecule due to the geometrical structure and surface electrostatic potential.

Circular polarization sensitive opto-neuromorphic operation at plasmonic hot electron transistor using chiral gold nanoparticles.

Opto-neuromorphic operation is critical for biological system to recognize the visual objects and mimicking such operation is important for artificial prosthesis as well as machine vision system for industrial applications. To sophisticatedly mimic biological system, regulation of learning and memorizing efficiency is needed, however engineered synthetic platform has been lack of controllability, which makes huge gap between biological system and synthetic platform. Here we demonstrated controllable learning and memorizing opto-neuromorphic operation at plasmonic hot electron transistor. Especially, circularly polarized light (CPL) sensitive synaptic characteristics and learning experience capability are enabled by incorporating chiral plasmonic nanoparticle. Furthermore, gate voltage gives rise to controllable neuromorphic operation due to hot electron injection and trapping effect, resulting in high remaining synaptic weight of ∼70% at negative gate voltage under CPL excitation. We believe that this discovery makes significant leap toward on-demand in-sensor computing as well as toward bio-realistic device.

Visual Outcome and Fluid Changes Between Eyes With Polypoidal Choroidal Vasculopathy Receiving Biosimilar CKD-701 or Reference Ranibizumab Therapy: A Post Hoc Analysis of a Phase 3 Randomized Clinical Trial.

PURPOSE: To compare the visual outcome and fluid features of a proposed biosimilar, CKD-701, versus the reference ranibizumab in eyes with polypoidal choroidal vasculopathy (PCV). METHODS: This was a post hoc analysis of a phase 3 randomized clinical trial assessing the efficacy and safety of CKD-701 and ranibizumab. A total of 73 PCV eyes were assigned randomly to either CKD-701 (36 eyes) or ranibizumab (37 eyes). The mean changes in best-corrected visual acuity (BCVA), central retinal thickness (CRT), pigment epithelial detachment (PED) volume, and fluid features were compared. RESULTS: After three loading injections, the mean change in BCVA (letters) was +7.50 in the CKD-701 group and +6.32 in the ranibizumab group (p = .447). The changes in CRT and PED volume of the CKD-701 group (-107.25 ± 102.66 µm and -0.22 ± 0.46 mm3) were similar to those of the ranibizumab group (-96.78 ± 105.00 µm and -0.23 ± 0.54 mm3) (p = .668 and p = .943, respectively). Proportions of eyes with subretinal, intraretinal and sub-retinal pigment epithelium (RPE) fluids after three loading injections were not different between CKD-701 group (33.3%, 13.9% and 42.9%) and ranibizumab group (51.4%, 16.2% and 40.0%) (p = .071, p = 1.000 and p = .808). The visual and anatomical changes were similar between two groups at month 6 and 12 (all, p > .05). CONCLUSION: Biosimilar CKD-701 monotherapy resulted in comparable visual and anatomical changes to those achieved with reference ranibizumab in PCV eyes.

Promoting hydrophilic cupric oxide electrochemical carbon dioxide reduction to methanol via interfacial engineering modulation.

Copper-based catalysts have been extensively investigated in electrochemical carbon dioxide (CO2) reduction to promote carbon products generated by requiring multiple electron transfer. However, hydrophilic electrodes are unfavourable for CO2 mass transfer and preferentially hydrogen (H2) evolution in electrochemical CO2 reduction. In this paper, a hydrophilic cupric oxide (CuO) electrode with a grassy morphology was prepared. CuO-derived Cu was confirmed as the active site for electrochemical CO2 reduction through wettability modulation. To enhance the intrinsic catalytic activity, a metal-oxide heterogeneous interface was created by engineering modulation at the interface, involving the loading of palladium (Pd) on CuO (CuO/Pd). Both the electrochemically active area and the electron transfer rate were enhanced by Pd loading, and significantly the reduced work function further facilitated the electron transfer between the electrode surface and the electrolyte. Consequently, the CuO/Pd electrode exhibited excellent excellent performance in electrochemical CO2 reduction, achieving a 54 % Faraday efficiency at -0.65 V for methanol (CH3OH). The metal-oxide interfacial effect potentially improves the intrinsic catalytic activity of hydrophilic CuO electrodes in electrochemical CO2 reduction, providing a conducive pathway for optimizing hydrophilic oxide electrodes in this process.

Photochemical tuning of dynamic defects for high-performance atomically dispersed catalysts.

Developing active and stable atomically dispersed catalysts is challenging because of weak non-specific interactions between catalytically active metal atoms and supports. Here we demonstrate a general method for synthesizing atomically dispersed catalysts via photochemical defect tuning for controlling oxygen-vacancy dynamics, which can induce specific metal-support interactions. The developed synthesis method offers metal-dynamically stabilized atomic catalysts, and it can be applied to reducible metal oxides, including TiO2, ZnO and CeO2, containing various catalytically active transition metals, including Pt, Ir and Cu. The optimized Pt-DSA/TiO2 shows unprecedentedly high photocatalytic hydrogen evolution activity, producing 164 mmol g-1 h-1 with a turnover frequency of 1.27 s-1. Furthermore, it generates 42.2 mmol gsub-1 of hydrogen via a non-recyclable-plastic-photoreforming process, achieving a total conversion of 98%; this offers a promising solution for mitigating plastic waste and simultaneously producing valuable energy sources.

Chiral plasmonic sensing: From the perspective of light-matter interaction.

Molecular chirality is represented as broken mirror symmetry in the structural orientation of constituent atoms and plays a pivotal role at every scale of nature. Since the discovery of the chiroptic property of chiral molecules, the characterization of molecular chirality is important in the fields of biology, physics, and chemistry. Over the centuries, the field of optical chiral sensing was based on chiral light-matter interactions between chiral molecules and polarized light. Starting from simple optics-based sensing, the utilization of plasmonic materials that could control local chiral light-matter interactions by squeezing light into molecules successfully facilitated chiral sensing into noninvasive, ultrasensitive, and accurate detection. In this Review, the importance of plasmonic materials and their engineering in chiral sensing are discussed based on the principle of chiral light-matter interactions and the theory of optical chirality and chiral perturbation; thus, this Review can serve as a milestone for the proper design and utilization of plasmonic nanostructures for improved chiral sensing.

Comparison of retinal thickness measurements among four different optical coherence tomography devices.

We sought to compare the retinal thickness measurements collected using different optical coherence tomography (OCT) devices. This prospective study included 21 healthy cases, and the retinal thickness was measured using the PLEX Elite (Carl Zeiss Meditec, Dublin, California, USA), DRI OCT-1 Atlantis (Topcon Corp, Tokyo, Japan), Cirrus 5000 HD-OCT (Carl Zeiss Meditec), and Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany), respectively. The mean central retinal thickness (CRT) and mean retinal thickness of the Early Treatment of Diabetic Retinopathy Study (ETDRS) area were compared. The CRT varied significantly among the different OCT devices (P < 0.001). Post-hoc analysis revealed that the CRT measured using PLEX Elite (278.95 ± 20.04 µm) and Spectralis (271.86 ± 17.92 µm) were similar, and both were greater than the CRT measurements of DRI OCT-1 (239.57 ± 21.06 µm) and Cirrus (256.76 ± 17.82 µm). Additionally, the mean retinal thickness in each ETDRS area showed significant differences among the four devices (all P < 0.001). The mean retinal thickness measured varied according to the device used, and this needs to be considered when comparing retinal thickness measurements taken with different devices.