Chiral nanoparticles offer new opportunities for designing functional materials with tunable optical and electrochemical properties. While cysteine and cysteine-containing peptides are commonly used as chiral agents in the synthesis of such nanoparticles, the use of alternative ligands remains limited. In this study, we introduce penicillamine as a new chiral agent in the seed-mediated growth of gold nanoparticles (AuNPs). The presence of L- or D-penicillamine induces chirality during nanoparticle growth, and its extent is examined at different growth stages using SEM. Structural evidence for enantioselective growth is also provided with high-resolution STEM. Circular dichroism spectroscopy of particle suspensions and dark-field scattering measurements at the single-particle level further suggest that the chirality is encoded in the nanoparticle morphology rather than being limited to surface-bound ligands. Importantly, dark-field scattering indicates that the AuNPs' chiral morphology is also preserved after drying on an Au electrode. To evaluate whether this morphological chirality translates into functional enantioselectivity, electrochemical measurements are performed using L- and D-cysteine as analytes on electrodes modified with chiral AuNPs. Cyclic voltammetry and electrochemical impedance spectroscopy show that electrodes modified with L-penicillamine-induced chiral AuNPs exhibit higher current densities (ca. 36%) and lower charge-transfer resistance toward L-cysteine oxidation. Similarly, D-penicillamine-induced chiral AuNPs show higher current densities for D-cysteine oxidation. This enantioselective interaction between enantio-matched pairs demonstrates that the encoded chirality influences molecular recognition processes at the electrode interface. Overall, this study establishes penicillamine-induced chiral AuNPs as versatile, label-free platforms for enantioselective electrochemical sensing.

Metal oxide subnanometric size clusters can be "small" but "powerful" in suppressing side-reactions such as the hydrogen evolution reaction (HER), thereby improving ammonia (NH3) product during the nitrate reduction reaction (NO3-RR). This study presents the synthesis of a carbon-vulcanized (C)-defective TiO2 nanosheet (TNS) composite, modified with subnanometric WO3 clusters. It is found that among various loadings, the electrocatalyst with 3 wt % WO3 (C-3%WO3-TNS) suppresses HER. NH3 production higher than 97% is achieved by incorporating CuNi (40:60 wt %) onto C-3%WO3-TNS (Cu40Ni60/C-3%WO3-TNS), as confirmed by in situ differential electrochemical mass spectrometry (DEMS). Chemical characterizations reveal that WO3 clusters influence the Ti3+/Ti4+ ratio, thereby potentially suppressing HER. It has also been found that NH3 formation is further facilitated by Cu40Ni60, which promotes faster NO3- reduction via a multistep reaction on the C-WO3-TNS supports. The synergy between Cu40Ni60, C, WO3, and defective TNS modulates the production of H-2 and NH3. This synergy can be attributed to the morphological and structural characteristics of the electrocatalyst, which indicate that Ni is positioned at specific edge sites over the C and TNS, while WO3 and Cu are well-distributed over the TNS. A mechanistic approach is proposed to explain the observed products by DEMS. This work highlights the dual potential of Cu40Ni60/C-3%WO3-TNS to suppress HER and promote NH3 synthesis, offering a promising strategy for tuning reaction pathways during NO3-RR.

The electrochemical conversion of nitrate to ammonia is crucial for nitrogen upcycling. This study investigates the effect of electrolyte cations (K+, Na+, and Li+) on nitrate electroreduction using NiO:SnO2 nanofibers. Among other products, in situ differential electrochemical mass spectrometry (DEMS) confirms that NH3 formation strongly depends on cation identity, inducing a shift in product selectivity from NH3 to H2. These results highlight the importance of cation-mediated pathways in aqueous systems and provide insight into ammonia synthesis.

We report the synthesis of heterojunction-architected bismuth titanate nanobelts obtained by mild reductive treatment of hydrothermally synthesized bismuth titanate (BT). The resulting defective material (BTD) comprises metallic Bi, Bi2Ti2O7, and Bi4Ti3O12, generating a ternary-phase heterostructure with interfacial defects. Structural and surface analyses by STEM, XRD, XPS, and cathodoluminescence, together with EIS under illumination, indicate that phase coupling and defect formation improve charge transport in BTD. In photocatalytic H2 evolution from water/methanol under UV irradiation, BTD reaches 382.89 mu mol g-1 cat h-1 at 1 h, outperforming BT (179.36 mu mol g-1 cath-1) and TiO2 (209.74 mu mol g-1 cat h-1). At 4 h, BTD continues with the highest H2 production. These results demonstrate that ternary phase engineering and defect-mediated heterojunction formation promote charge separation and photocatalytic hydrogen evolution in bismuth titanate nanobelts.

Abstract Controlling polymorphism in ceramic microarchitectures is essential for linking processing, structure, and function yet remains difficult for ceramics produced by two-photon lithography (TPL). During thermal conversion, crystallite growth typically promotes the thermodynamically stable monoclinic (m) phase, restricting access to tetragonal (t)-ZrO2. Here, we show that infrared (IR) flash annealing stabilizes t-ZrO2 microarchitectures over a broad 600–1000 °C treatment window. Rapid IR heating (20 °C s–1) limits crystallite growth and suppresses the t-to-m transformation commonly observed near 750 °C under slower annealing. Scanning transmission electron microscopy (STEM) confirms crystallite-size-dependent t-stabilization during rapid IR heating, while Europium (Eu3+) serves as an embedded optical probe of local symmetry, providing distinct photoluminescence signatures without destructive preparation. Flash thermal processing controls polymorphism, while luminescent symmetry probing enables its non-destructive diagnosis in 3D ceramic microarchitectures, providing a transferable approach for studying phase evolution in lanthanide-doped ceramics.

This study investigates the synergistic effect of NiCu catalyst supported on carbon-TiO2 during the hydrogen evolution reaction (HER) in alkaline media. Ni60Cu40 metallic ratios are supported on carbon Vulcan (NiCu/C) and on a modified carbon Vulcan matrix containing commercial TiO2 (NiCu/C-T0) and defect-rich TiO2 (NiCu/C-TD). The morphological, structural, and chemical compositions, as determined by XRD, STEM-EDX, XPS, and Raman, confirmed that TiO2 in NiCu/C-TD possesses a relatively high concentration of Ti3+ species (ca. 20%) when compared to NiCu/C-T0, indicating the presence of defective species in NiCu/C-TD. The defective functionality of C-TD is electrochemically demonstrated, with the NiCu/C-TD catalyst showing superior HER activity, as evidenced by differential electrochemical mass spectrometry (DEMS). This activity relates to charge-transfer within the catalyst, HER's low rate-determining step, and the electrochemical overpotential of the defective TiO2 electrocatalyst. Overall, the catalytic activity is attributed to the synergistic interplay between NiCu and the defective-rich TiO2 support, which modulates the adsorption/desorption of intermediates, facilitates interfacial electron transfer, and leads to a higher hydrogen production rate for NiCu/C-TD. These results provide a strategy for designing defect-rich HER electrocatalysts.

This work addresses the challenge of fabricating crystalline single-phase luminescent 3D microstructures by demonstrating a fabrication process of yttrium aluminum garnet doped with cerium (YAG:Ce3+) 3D micro-objects. Precursors were synthesized via a sol-gel method and characterized by refractive index (RI) measurements, Fourier-transform infrared spectroscopy (FT-IR), and thermogravimetric (TG) analysis to verify chemical composition changes during photopolymerization and thermal treatment. Multiphoton laser 3D lithography (MP3DL) was employed to produce hybrid metal-organic 3D structures, which were subsequently converted into crystalline ceramics through controlled 3-step annealing. Structural analysis by X-ray diffraction (XRD) confirmed the formation of single-phase cubic YAG across Ce3+ concentrations up to 5 mol-% in 3D objects, while scanning electron microscopy (SEM) revealed isotropic shrinkage (ca. 39%) and well-preserved geometries with sub-micrometer features after pyrolysis. The smallest feature of a crystalline 3D object achieved was 0.48 mu m with a spatial resolution down to 2.4 mu m. Luminescence measurements showed characteristic Ce3+emission centered at 558 nm, with maximum intensity at 2 mol% doping. These findings establish a reliable pathway to fabricate thermally stable, high-resolution, luminescent single-phase YAG:Ce3+ 3D micro-objects, enabling their integration into optoelectronic and photonic applications.

Low-temperature, solution-processed carbon-based perovskite solar cells (c-PSCs) often suffer from surface defects and nonideal crystallization caused by rapid antisolvent quenching of MAPbI3. To this end, incorporating polymers as antisolvent additives offers a simple route to regulate crystallization and reduce interfacial defects. Here, four donor polymers-P3HT, PCE10, PM6, and PM7-are introduced during MAPbI3 deposition. Their distinct Highest Occupied Molecular Orbital (HOMO) energy levels enable us to probe how energetic alignment influences their interaction with MAPbI3 surfaces and their passivation capability. The additives are found to improve crystallinity, yielding larger grains and lower trap densities. In particular, PM7 provides the highest enhancements because its HOMO level lies closest to the MAPbI3 valence band, enabling more favorable interfacial passivation and more effective suppression of surface recombination. Consequently, PM7-treated films exhibit longer photocarrier lifetimes, lower ideality factors, reduced interfacial resistance, and smaller trap-filled limit voltages. Devices using PM7 reach a PCE of 14.6%, a 53.8% improvement over the control. Overall, this study demonstrates that the HOMO level of antisolvent additives is a decisive factor governing interfacial interactions and enhancing MAPbI3 passivation.

Microstructures arrayed over a substrate have shown increasing interest due to their ability to provide advanced 3D cellular models, which open up new possibilities for cell culture, proliferation, and differentiation. Still, the mechanisms by which physical cues impact the cell phenotype are not fully understood, hence the necessity to interrogate cell behavior at the highest resolution. However, cell 3D high-resolution optical imaging on such microstructured substrates remains challenging due to their complexity as well as axial calibration issues. In this work, we address this issue by leveraging the geometrical characteristics of fractal-like structures, which serve as axial calibration tools and modulate cell growth. To this end, we use multiscale 3D SiO2 substrates consisting of spatially arrayed octahedral features of a few micrometers to hundreds of nanometers. Through optimizations of both the structures and optical imaging conditions, we demonstrate the potential of these 3D multiscale structures as an alternative to electron microscopy for material imaging but also as calibration tools for 3D super-resolution microscopy. We used their multiscale and known geometry to perform lateral and axial calibrations in 3D single-molecule localization microscopy (SMLM) and assess imaging resolutions. We then utilized these substrates as a platform for high-resolution bioimaging. As a proof of concept, we cultivate human mesenchymal stem cells on these substrates, revealing very different growth patterns compared to flat glass. Specifically, the spatial distribution of cytoskeleton proteins is vastly modified, as we demonstrate with a 3D SMLM assessment.

Glycogen synthase kinase-3 (GSK-3) is linked with multiple CNS conditions, including glioblastoma (GBM). Compared to the GSK-3β isoform, structure-based inhibitor design targeting GSK-3α is limited. Virtual screening was employed to identify GSK-3α inhibitors with CNS-active potential. Using a GSK-3α homology model, an optimized protocol with three-dimensional (3D)-pharmacophore filtering and Glide-SP docking was used to screen the ZINC20 biogenic subset. From 14 compounds selected for binding assay validation, three novel hit compounds were identified, with 1 (4-phenyl-1H-benzofuro[3,2-b]pyrazolo[4,3-e]pyridine scaffold) exhibiting nanomolar activity against GSK-3α/β (IC50s ∼ 0.26 μM). Selectivity profiling (12 homologous kinases) revealed selectivity for GSK-3α/β and protein kinase A (PKA). Compound 1 was more potent against three GBM cell lines (cell viability IC50s = 3-6 μM at 72 h) compared to benchmark GSK-3 inhibitor, 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8), and nontoxic to human astrocytes. It demonstrated CNS-active potential in an all-human in vitro blood-brain barrier GBM model, good in vitro metabolic stability, excellent predicted oral bioavailability and represents a promising lead compound for development.

Mechanochemical coupling reactions are typically single-site events that are thermally driven, require an inert atmosphere, and are kinetically slow under ball milling conditions. Here, we demonstrate the rapid 4-fold single-pot mechanochemical C-N coupling of tetrabromopyrene and phenothiazine leading to a novel pyrene-phenothiazine (PYR-PTZ) molecule that is shown to be an effective hole-transport material (HTM) in a perovskite solar cell (PSC). When compared to previously reported mechanochemical C-N coupling reactions, the mechanosynthesis of PYR-PTZ is achieved in just 99 min of ball-milling under ambient conditions without a glovebox or the need for external heating. This represents an advance over previous methods for the synthesis of HTMs and opens new avenues for exploring the discovery of other organic HTMs for PSC applications. The photophysics, crystal structure, and electron transport properties of the novel HTM have been characterized using a combination of experimental and density functional theory methods. In an encapsulated PSC, the photoconversion efficiency of PYR-PTZ is comparable to that of the widely used spiro-MeOTAD molecule, but the stability of PYR-PTZ is superior in a naked PSC after 4 weeks. This work demonstrates the value of mechanochemistry in the sustainable synthesis of new organic HTMs at significantly reduced costs, opening up new opportunities for mechanochemistry in optoelectronics.

This study investigates the effect of different solvents used in the synthesis of carbon quantum dots (CQDs) on the electrocatalytic performance of MoS2/CQD heterostructures for the hydrogen evolution reaction (HER). While previous research focused on CQDs synthesized with deionized water, little attention has been given to the influence of other solvents on CQD electrocatalytic behavior. To address this, we synthesized MoS2 on 3D carbon cloths via a hydrothermal method and subsequently incorporated CQDs synthesized using deionized water, glycerol, and dimethylformamide (DMF). The choice of solvent significantly impacts their morphology, crystallinity, surface, and electrochemical properties. In particular, MoS2 nanosheets became smaller with increased disordered structures and defect sites, particularly sulfur vacancies. Among the heterostructures, MoS2/CQDs-Glycerol showed superior performance, with an onset overpotential of 130 mV and Tafel slope of 53 mV/dec at 10 mA/cm2, outperforming MoS2/CQDs-DI (149 mV, 68 mV/dec) and MoS2/CQDs-DMF (185 mV, 106 mV/dec). The enhanced performance of MoS2/CQDs-Glycerol is attributed to its larger active surface area (C dl of 228.7 mF/cm2) and lower charge transfer resistance (R ct of 2.25 Omega), which may be due to the formation of more Mo-S edges on the vertical plane, serving as active sites. This study demonstrates that glycerol is the most effective solvent in CQD synthesis for enhancing HER performance by improving the morphology, surface properties, and charge transfer.

Feynman's statement, "There is plenty of room at the bottom", underscores vast potential at the atomic scale, envisioning microscopic machines. Today, this vision extends into 3D space, where thousands of atoms and molecules are volumetrically patterned to create light-driven technologies. To fully harness their potential, 3D designs must incorporate high-refractive-index elements with exceptional mechanical and chemical resilience. The frontier, however, lies in creating spatially patterned micro-optical architectures in glass and ceramic materials of dissimilar compositions. This multi-material capability enables novel ways of shaping light, leveraging the interaction between diverse interfaced chemical compositions to push optical boundaries. Specifically, it encompasses both multi-material integration within the same architectures and the use of different materials for distinct architectural features in an optical system. Integrating fluid handling systems with two-photon lithography (TPL) provides a promising approach for rapidly prototyping such complex components. This review examines single and multi-material TPL processes, discussing photoresin customization, essential physico-chemical conditions, and the need for cross-scale characterization to assess optical quality. It reflects on challenges in characterizing multi-scale architectures and outlines advancements in TPL for both single and spatially patterned multi-material structures. The roadmap provides a bridge between research and industry, emphasizing collaboration and contributions to advancing micro-optics.

Intravascular surgical instruments require precise navigation within narrow vessels, necessitating maximum flexibility, minimal diameter, and high degrees of freedom. Existing tools often lack control during insertion due to undesirable bending, limiting vessel accessibility and risking tissue damage. Next-generation instruments aim to develop hemocompatible untethered devices controlled by external magnetic forces. Achieving this goal remains complex due to testing and implementation challenges in clinical environments. Here we assess the operational effectiveness of hemocompatible untethered magnetic robots using an ex vivo porcine aorta model. The results demonstrate a linear decrease in the swimming speed of untethered magnetic robots as arterial blood flow increases, with the capability to navigate against a maximum arterial flow rate of 67 mL/min. The untethered magnetic robots effectively demonstrate locomotion in a difficult-to-access target site, navigating through the abdominal aorta and reaching the distal end of the renal artery.

Lanthanide-doped ZrO2 ceramics are promising materials for optics due to their high refractive index and tunable luminescent properties. In this study, we investigated the impact of Yb3+ and Er3+ dopant concentrations on the emission behavior of lanthanide-doped 3D ZrO2 microarchitectures fabricated using two-photon lithography. Thermal treatments have been carried out at 600 degrees C and 750 degrees C to promote the stabilization of the ZrO2 tetragonal phase (t-ZrO2) and at 1000 degrees C to induce phase transition in ZrO2 to the monoclinic (m-ZrO2) phase in the 3D microarchitectures. Scanning transmission electron microscopy confirmed the crystallinity changes across the thermal treatments. Photoluminescence (PL) and cathodoluminescence (CL) measurements confirm emission bands of Yb3+ and Er3+ single dopants and Yb3+:Er3+ co-dopants. Variations in Yb3+ content reveal that the PL emission of Er3+ increases (e.g., 4S3/2 -> 4I15/2), which is attributed to the interplay between the dopant concentrations, defect structures and the ZrO2 host. The results highlight the importance of ZrO2microarchitectures' crystallinity and co-doping relationship, which enable the promotion of Er3+ emissions. We expect our research will find applications in 3D optical systems.

Controlling quantum light-matter interactions at scales smaller than the diffraction limit at the single quantum emitter level is a critical challenge to the goal of advancing quantum technologies. We introduce a novel material platform that enables precise engineering of spontaneous emission changes in molecular single emitters through 3D nanofields. This platform is based on a 3D hollow plasmonic nanomaterial arranged in a square lattice, uniformly scalable to the centimeter scale while maintaining unit cell geometry. This coupled system leads to billions of Purcell-enhanced single emitters integrated into a nanodevice. Using far-field single-molecule super-resolution microscopy, we investigate emission modifications at the single-emitter level, enabling molecular position sensing with resolution surpassing the diffraction limit. By combining the nanolocalization with time correlation single photon counting, we probe molecule per molecule enhanced quantum light-matter interactions. This 3D plasmonic geometry significantly enhances light-matter interactions, revealing a broad range of lifetimes – from nanoseconds to picoseconds – significantly increasing the local density of states in a manner that depends on both molecular position and dipole orientation, offering extreme position sensitivity within the 3D electromagnetic landscape. By leveraging these plasmonic nanostructures and our method for measuring single-molecule Purcell-enhanced nano-resolved maps, we enable fine-tuned control of light-matter interactions. This approach enables the on-demand control of fast single-photon sources at room temperature, providing a powerful tool for molecular sensing and quantum applications at the single-emitter level.

Metal-organic frameworks (MOFs) are a versatile class of materials with significant potential for electrochemical CO2 reduction to multicarbon products. Most MOFs for electrocatalysis rely on benzene-ring-containing linkers, but their limited electrocatalytic activity hinders progress. Flexible MOFs, constructed from aliphatic-chain-containing linkers, offer an alternative due to their ability to respond to external stimuli such as electricity. Despite their potential, few studies have explored flexible MOFs for electrochemical CO2 reduction to value-added liquid products. This work synthesized two MOFs using metal nuclei (Mg and Zn) and distinct organic linkers: oxalic acid and 2,5-dihydroxyterephthalic acid (H4DOBDC, MOF-74). Electrochemical analysis revealed that the flexible MOF derived from oxalic acid exhibited superior charge transport properties, as confirmed by electrochemical impedance spectroscopy (EIS). Structural and chemical analyses, such as TEM, XRD, XPS, and acidity tests with pyridine, were performed using the synthesized MOFs. In situ ATR-FTIR during electrolysis and post-electrolysis using 1H NMR revealed the production of diverse carbon products, including ethanol, isopropanol, and methanol. The oxalic acid MOF demonstrated superior selectivity over well-known MOF-74 at -0.19 V vs. RHE. This study highlights the advantages of flexible MOFs over conventional benzene-based frameworks and paves the way for their application in CO2 electroreduction to liquid products.

Two-photon lithography (TPL), as an additive manufacturing (AM) technique, facilitates the low-temperature fabrication of microarchitectures, yet the integration of spatially varying inorganic compositions within a microarchitecture footprint remains largely unexplored. This work examines the transition from single to multi-material manufacture and, study the optical properties of SiO2 glass and its combination with inorganic loadings. The latter approach, i.e., multi-composition printing, is evaluated using a fluidic cell for photoresin exchange, enabling spatially varied patterning. Using thermal annealing at 650 degrees C, single- and multi-inorganic printed replicas are produced with tailored chemical components. Yet, even though state-of-the-art photoresins are well-optimized for single-material printing (e.g., SiO2, TiO2, and ZrO2), the necessity of adjusting photoresins is highlighted for multi-material printing. Annealed multi-printed replicas rely on composition-specific photoresins, such as the inorganic mass fraction, which can significantly influence the fidelity of the post-annealed microarchitecture. Additionally, insights into these microarchitectures' chemical, morphological, and optical behavior are provided through characterization methods, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), confocal fluorescence microscopy, and cathodoluminescence (CL). The results highlight the importance of formulation and processing conditions for achieving inorganic multi-printing.

The electrochemical synthesis of α ${\alpha }$ -amino acids at room temperature and pressure is a sustainable alternative to conventional methods like microbial fermentation and Strecker synthesis. A custom-built zero-gap flow electrolyzer was used to study the electrosynthesis of alanine via the electrocatalytic reductive amination (ERA) of the corresponding biomass-derivable α ${\alpha }$ -keto acid precursor - pyruvic acid (PA), and hydroxylamine (NH2OH) at very low pH. Non-toxic, abundant, and easy to prepare TiO2/Ti electrocatalysts were utilized as the cathode. Three TiO2/Ti felt electrodes with different oxide thicknesses were prepared and their characterization results were correlated with their respective electrochemical performance in terms of Faradaic efficiency η ${\eta }$ , and partial current density j ‾ ${\left|\overline{j}\right|}$ . Cyclic voltammetry indicated a different electrocatalytic reduction process on hydrothermally treated electrodes, compared to thermally oxidized ones. Hydrothermally treated electrodes were also found to have the thickest porous anatase layer and achieved 50-75 % alanine conversion efficiencies. Optimization showed that the cell potential, reactant flow rate and the PA: NH2OH ratio were crucial parameters in determining the conversion efficiency. η ${\eta }$ and j ‾ ${\left|\overline{j}\right|}$ were found to significantly decrease when an excess of is used and, an optimal alanine η ${\eta }$ of 75 % was achieved at 2.0 V applied cell potential and 10 mL/h reactant flow rate.