Chemistry and Materials Science

Abstract: Breast-cancer management depends on reproducible molecular classification, yet tissue-based assays provide only spatially and temporally restricted views of a heterogeneous disease. Aptamers are programmable single-stranded DNA or RNA ligands that can integrate molecular recognition with biosensing, liquid-biopsy capture and targeted delivery. This Review follows the translational chain from aptamer selection and molecular recognition to subtype resolution, signal or cargo conversion, biological validation and clinical translation. We compare HER2-directed aptamers, ERα- and PHB2-associated tools for hormone-receptor-positive disease, and phenotype-oriented ligands for triple-negative breast cancer. We further organize aptasensors by signal-conversion mechanism, distinguish analytical performance in buffer from that in clinical matrices, and clarify the complementary role of aptamers in liquid-biopsy workflows, including enrichment rather than direct sequence-variant detection of circulating tumour DNA. For theranostic systems, affinity alone is insufficient; pharmacokinetics, receptor trafficking, endosomal escape and comparator-controlled efficacy ultimately determine functional benefit. Aptamers are therefore most compelling as modular recognition elements for multiplexing, reversible engineering and targeted delivery. Progress will depend on transparent selection reporting, orthogonal target validation and prospective multicenter studies.

Abstract: The increasing number of electronic devices and the development of telecommunication and wireless communication have increased the density of secondary non-ionizing waves and created electromagnetic wave pollution. To prevent their impact, electromagnetic interference (EMI) shielding materials are used. Due to physico-chemical properties, such as lightweight, chemical stability and tunable electrical properties, graphene and its derivate, graphene oxide (GO), seem to be a smart alternative. Its flexibility, biocompatibility, and sheet-like morphology make it particularly attractive for functionalization of textile fabrics. This paper presents innovative functionalized cotton fabrics modified with an agent-free approach using reduced GO (rGO) and rare-earth-based nanoparticles (REVO4: SmVO4, GdVO4, NdVO4, DyVO4). Cotton was functionalized with GO and REVO4 by repeating dipping, drying, and reduction cycles, from 1 to 30. Scanning electron microscopy (SEM) proved that GO sheets were homogeneously covering cotton fibers, while small spherical objects were identified across the fibers and confirmed REVO4 deposition. The effectiveness of EMI shielding in the samples with the highest number of deposited GO and REVO4 layers was between 20 and 28% across the band 2.60 to 3.95 GHz frequency range. Although shielding effectiveness is limited, the results highlight the potential of rGO and rare-earth-based nanoparticles as promising candidates in the professional clothing of workers in radar and telecommunications.

Abstract: Inspired by the newly discovered sandwich D_5d [Os(η⁵-B₅H₁₀)₂] as a carbon-free analog of ferrocene [Fe(η⁵-C₅H₅)₂] (Science 392, (2026): 411) and based on extensive global searches and first-principles theory calculations, we present herein the viable possibility of a staggered sandwich bis(η⁶-cycloborane)chromium D_6d [Cr(η⁶-(BH)₆H₆)₂] (1) with two equivalent η⁶- (BH)₆H₆ ligands isovalent with benzene as the boron analog of the eclipsed bis(η6-benzene)chromium D_6h [Cr(η⁶-C₆H₆)₂] (2). Detailed coordination bonding pattern, energy decomposition, and magnetically induced ring current analyses indicate that D_6d 1 matches the 18-electron rule (1S²1P⁶1D¹⁰) and exhibits similar aromaticity with D_6h 2, rendering high stability to the system. The metal-ring coordination bonding in D_6d 1 is dominated by effective Cr → (η⁶-(BH)₆H₆)₂ δ-back-donations which appear to be significantly stronger than the corresponding Cr → (η⁶-C₆H₆)₂ δ-back-donations in D_6h 2, leading to an unusually short ring-ring distance of 2.70 Å and large HOMO-LUMO gap of 7.06 eV in 1. D_6d 1 and D_6h 2 can also be used as building blocks to form their sandwich tetramers D_2h [Cr₄(BH)₄₈H₂₈] (3) and D_2h [Cr₄C₄₈H₂₈] (4) and sandwich two-dimensional nanosheets [Cr(η⁶-(BH)₆)₂] (5) and [Cr(η⁶-C₆)₂] (6) via partial or complete dehydrogenations, respectively.

Abstract: Novel iodinated cobalt bis(dicarbollide) conjugates with acridine were synthesized by the direct iodination reaction of cobalt bis(dicarbollide) conjugates and acridine with crystalline iodine. The cytotoxicity of new compounds against different human cell lines was evaluated. One of these compounds was found to be non-toxic for all cell types and was combined with polyvinylpyrrolidone to form a non-covalent complex to increase its water solubility. The BNCT experiment showed that pre-incubation with a new boron-containing complex followed by neutron irradiation reduces the survival of T98G glioblastoma cells to 25% and B16 melanoma cells to 17%. The biodistribution of the boron-containing compound ACR-PVP was investigated in a B16F10 melanoma murine model. Maximum uptake in tumor and healthy tissues was observed 15 minutes following single intravenous administration. ACR-PVP exhibited a considerably higher tumor-to-muscle ratio (5.4) relative to BPA (3.0), thereby indicating its potential as a promising candidate for boron neutron capture therapy. This study creates prerequisites for further research in the development of methods for synthesizing BNCT agents based on acridine.

Abstract: Pladienolide-B, a macrocyclic polyketide isolated from Streptomyces platensis Mer-11107, displays potent antiproliferative and antitumor activities by targeting the SF3b subunit of the spliceosome. Herein, we report a divergent, stereoselective synthetic route to access both the C1–C8 and C9–C13 fragments of the core moiety of Pladienolide-B starting from a common, inexpensive chiral pool precursor, L-malic acid. Key stereocenters and structural motifs were established using Sharpless asymmetric epoxidation, regioselective nucleophilic epoxide opening, Mannich reaction for exo-methylene introduction, and a tandem iodination–zinc elimination cascade. This unified precursor approach offers a streamlined tactical route toward the core macrolide framework.

Abstract: Soy isoflavones exhibit diverse health-promoting effects, including antioxidant and anti-inflammatory activities. However, these biological effects have largely been attributed to the modulation of cellular signaling pathways, whereas the influence of intestinal microbial metabolism on their direct radical-scavenging properties remains poorly understood. In this study, efficient synthetic routes were established for the major intestinal bacterial metabolites daidzein and genistein, equol (Eq), dehydroequol (DEq), 5-hydroxyequol (5-OH-Eq), and, for the first time, 5-hydroxydehydroequol (5-OH-DEq), and their direct radical-scavenging activities, reaction mechanisms, radical-scavenging capacities, and DNA protective effects were systematically evaluated. Introduction of a C-ring double bond markedly enhanced direct radical-scavenging activity, whereas the parent isoflavones and their reduced metabolites exhibited little or no activity. Among the compounds examined, 5-OH-DEq exhibited the highest antioxidant activity, scavenging radicals predominantly through a hydrogen atom transfer, with a second-order rate constant of 1.44 × 10³ M⁻¹ s⁻¹, exceeding that of Trolox and a radical-scavenging capacity of approximately three radical equivalents per molecule. Moreover, 5-OH-DEq protected plasmid DNA against radiation-induced oxidative damage. These findings demonstrate that intestinal microbial metabolism can function as a form of metabolic activation, converting dietary isoflavones into potent direct antioxidants. 5-OH-DEq was identified as a previously unexplored antioxidant metabolite and a promising lead scaffold for further development of next-generation phenolic antioxidants.

Abstract: Zinc-substituted copper chromite spinels with the general composition Cu₁₋xZnₓCr₂O₄ (x = 0, 0.25, 0.50, 0.75, and 1.00) were synthesized by the homogeneous co-precipitation method. The synthesized materials were systematically characterized using powder X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis, energy-dispersive X-ray (EDX) spectroscopy, and Fourier-transform infrared (FTIR) spectroscopy. The XRD patterns confirmed the formation of the spinel phase, while EDX analysis verified the elemental composition and stoichiometry of the prepared materials. The catalytic performance of the synthesized spinels was evaluated for the liquid-phase oxidation of cyclohexane using 70% tert-butyl hydroperoxide (TBHP) as the oxidizing agent. The results demonstrated that the zinc-substituted copper chromite spinels exhibit significant catalytic activity towards cyclohexane oxidation. Furthermore, reusability studies indicated that the catalysts retain their catalytic performance and structural stability under the employed reaction conditions, demonstrating their potential as reusable heterogeneous catalysts for liquid-phase oxidation reactions.

Abstract: Kraft cooking kinetic of poplar wood (Populus deltoides and Populus nigra) was investigated using chips of controlled size, and various enzymatic/mechanical pretreatments of the chips were attempted to observe the effects on pulp quality. Batch Kraft cooks of small amounts of untreated wood chips was carried out in mini-autoclaves at 140 - 165°C. Delignification rate constants and apparent activation energy during the bulk phase were determined. Various mechanical pretreatments, using a modular screw device (MSD) with or without xylanase impregnation prior to the cooks, were also investigated. Cooks were monitored through pulp yield, kappa number, fiber morphology, viscosity-average degree of polymerization (DPv) and residual effective alkali (REA). The results showed a variable, temperature-dependent activation energy of about 100 kJ/mol for the bulk delignification with a non-linear Arrhenius behavior suggesting a shift from reaction-controlled to diffusion-controlled kinetics as temperature increased . The effectiveness of xylanase impregnation was limited, due to chips thickness that limits enzymes penetration. MSD and MSD-Xylanase pretreatments significantly reduced fiber length (from 871 µm to 845 µm and 784 µm, respectively) and increased fines content (from 20.3% to 26.3% and 29.1%, respectively), indicating degraded fiber quality after the cooks of pretreated chips. Variability in pulp yield and REA was too high to reach statistical significance. Finally, it was shown that neither of these pretreatments could improve pulp quality in terms of fiber morphology and pulp strength properties, but this study opens the way towards utilization of pretreatments to improve pulp fibrillation for nanocellulose production.

Abstract: Mesoporous silicate nanoparticles are known for pore size, pore volume, high surface area, and tunable surface properties and as a result, have found application in medicine, healthcare, advanced materials, and devices. Furthermore, tailoring the silicate domain with certain metals has advanced the tissue engineering properties by moderating the cellular function at the molecular level for therapeutic response. However, scarce efforts have been made to explore systemic methods that could change the structure and shape of these particles and their effects on biological properties. Here, we have focused on, using Design of Experiments (DoE), optimizing reaction conditions for the synthesis of mesoporous strontium silicate nanostructures (NS) (nanoparticles – NPs and nanorods – NRs) with different physico-chemical properties. The conditions allowed change in shape from NPs to NRs by tailoring the concentration of liquid ammonia (NH4OH, 82.7 mM to 248.2 mM) during the pre-synthesis incubation state. In addition, the optimized reaction conditions allowed modulating the physico-chemical properties such as surface area, surface charge, amount of metal, pore diameter, pore volume, tailored degradation profile and release profile of the loaded drug (gentamicin). Finally, the protocol has the advantage of allowing incorporation of other metals such as cerium, rhodium, and ruthenium independently and/or in combination.

Abstract: Poly(lactic acid) (PLA) and polyhydroxyalkanoates (PHAs) are leading bio-based and biodegradable polyesters, but brittleness, narrow processing windows, and morphology-sensitive performance limit many durable applications. Polyhydroxyurethanes (PHUs), formed mainly by cyclic carbonate–amine polyaddition without isocyanates, combine urethane groups with pendant hydroxyls and can be designed as thermoplastics or exchangeable networks. These features make PHUs plausible tougheners and interfacial modifiers for PLA/PHA blends, yet direct evidence for ternary PLA/PHA/PHU systems remains scarce. This critical narrative review therefore separates direct polyester/PHU evidence from transferable results in PLA/PHA, PLA/thermoplastic-polyurethane, and dynamic-PHU systems. It connects monomer functionality, diamine structure, hydroxyl density, molar mass, and reversible chemistry to phase localization, interfacial adhesion, stress dissipation, melt processing, and repeated-use behavior. Published results show that polyurethane-like modifiers can provide large toughness gains when domain size and continuity are controlled, while thermoplastic PHUs can be melt blended and interact with PLA. However, hydrogen bonding does not by itself prove compatibility, dynamicity, recyclability, or biodegradability. A safe processing-relaxation window and a staged end-of-life assessment are proposed. The resulting design rules define the experiments needed to establish whether PHUs can deliver toughness, reprocessability, and credible environmental performance simultaneously.

Abstract: A Hastelloy N-like MoNiCr alloy produced by wire-laser directed energy deposition (W-DED) was exposed to eutectic LiF–BeF₂ (FLiBe) at 750 °C for 1000 h to assess the effects of manufacturing-generated surface states on corrosion response. Surface-skin coupons were extracted from as-built (AB) and hot-isostatically pressed (HIP) portions of a W-DED cube while preserving either the deposited surface or a wire electrical-discharge-machined (wire-EDM) surface. High-purity LiF and BeF₂ powders were mixed to the eutectic composition (66 mol% LiF–34 mol% BeF₂), melted at 700 °C under nitrogen, and the salt was subsequently remelted and poured over specimens in individual graphite crucibles before hermetic enclosure in laser-welded AISI 304 capsules. Optical profilometry compared exposed coupons with adjacent unexposed reference regions; metallography, SEM, and EDS evaluated microstructure and near-surface chemistry. Preserved deposited surfaces largely retained their orientation-dependent topography, whereas exposed wire-EDM surfaces had lower height-related roughness parameters than the unexposed references and developed a more uniform chromium-depleted region. HIP altered internal microstructure more strongly than macroscopic surface morphology. Because redox potential and a complete material balance were not measured, the results are interpreted as comparative static-screening data for MSR service. Mean chromium-depletion depth was approximately 8 ± 2 µm for preserved W-DED surfaces and 11 ± 1 µm for wire-EDM surfaces.

Abstract: Diatoms—unicellular microalgae essential for global ecosystems—synthesize nanostructured siliceous frustules composed of valves and girdle bands. In recent years, these frustule components have attracted increasing attention as sustainable, eco-friendly, and cost-effective alternatives to selected artificially fabricated micro/nanostructures used in micro- and nanosystems, particularly in fields such as photonics, sensing, and microfluidics, leading to the rise of diatom nanotechnology. Yet, the fabrication of commercially viable diatom-based devices remains hindered by several bottlenecks, including challenges associated with the precise assembly and integration of frustule-derived components within sophisticated micro- and nanosystems. In this perspective, we focus on these challenges and propose automated micromanipulation as a potentially transformative approach for addressing them.

Abstract: Campylobacter jejuni tops the list of bacteria responsible for gastroenteritis in humans. Knowledge of capsular polysaccharide (CPS) fine structure allows for the design of chemical conjugation strategies and identification of gene clusters for bioconjugations. CPSs are the basis for a multivalent C. jejuni glycoconjugate vaccine that has as key serological markers variably linked O-methyl-phosphoramidate (MeOPN) moieties and heptoses of rare configurations. Previously, the activation strategy for C. jejuni CPSs whose backbones contained no vicinal diols (serotypes HS:4, HS:10, HS:15, HS:23/36 and HS:53) was based on oxidation of the non-reducing end sugar with periodate, followed by conjugation to protein via reductive amination. Here, we describe the approach taken to functionalize C. jejuni CPSs with inner regions susceptible to periodate centered on TEMPO/bleach-mediated oxidation of primary hydroxyls to carboxyls followed by carbodiimide-directed conjugation. This work describes the syntheses and immunogenicities of such C. jejuni CPS-conjugates, specifically those of serotypes HS:1, HS:2 and HS:3. The stoichiometric TEMPO/bleach-oxidation of CPSs showed preference for specific primary hydroxyl groups, such as C7 of 6-deoxy-heptoses, and furnished conjugates that induced strong IgG responses against the native C. jejuni CPSs. It is postulated that the enhanced immunogenicity of the described conjugates is due to the preservation of CPS structures and the zwitterionic character of CPSs, afforded by the native MeOPN units and unreacted carboxyls.

Abstract: In this study, CdTe thin films were fabricated on soda-lime glass substrates via pulsed laser deposition and evaluated as immobilized semiconductor photocatalysts for the degradation of methylene blue under visible-light irradiation. XRD, AFM, SEM-EDS, photoluminescence, and photophysical characterization techniques were employed to elucidate the relationship between photocatalytic response and the structural, morphological, elemental, and optical characteristics of the fabricated thin films. Results show that increasing film thickness improves crystallinity, surface roughness, stoichiometry, optical absorption, and charge-carrier dynamics, while reducing the optical band gap from 1.71 to 1.37 eV. Among the fabricated samples, the 350 nm-thick CdTe film exhibited the highest photocatalytic performance, achieving 93.32% MB degradation after 220 minutes of visible-light irradiation, following pseudo-first-order kinetics with a rate constant of 0.0118 min⁻¹. Photocatalytic performance was strongly influenced by solution pH, with optimal degradation at pH 10. Furthermore, scavenger experiments demonstrated that reactive oxygen species, particularly superoxide radicals, played a dominant role in the overall degradation mechanism. These findings highlight CdTe thin films produced by PLD as promising immobilized photocatalysts for efficient wastewater treatment.

Abstract: Organ-on-chip (OoC) systems — microfluidic devices lined with living human cells that reconstitute organ-level structure and function in vitro — are, at the materials level, chemical constructs: cross-linked siloxane or hydrocarbon polymer networks, plasma-activated and silanized at defined interfaces, coated with adsorbed or covalently immobilized extracellular-matrix proteins, and in continuous chemical exchange with the small-molecule drugs and metabolites they are built to study. This extensively referenced perspective takes that materials- and surface-chemistry foundation as its organizing frame. It first details the polymer network chemistry of poly(dimethylsiloxane) (PDMS) device fabrication — hydrosilylation cross-linking, epoxide-based photoresist chemistry in mold production, oxygen-plasma-driven silanol (Si–OH) generation, siloxane (Si–O–Si) covalent bonding, the thermodynamically driven hydrophobic recovery that constrains device assembly windows, and silane-coupling and carbodiimide bioconjugation chemistry used to immobilize extracellular-matrix proteins at defined interfaces. It then addresses, in quantitative chemical terms, the single limitation most consequential to pharmaceutical use of these devices: PDMS's bulk absorption of lipophilic small molecules, contrasted against surface-adsorption-dominated, more chemically inert alternatives such as cyclic olefin copolymer (COC) and styrene-ethylene-butylene-styrene (SEBS) elastomers, drawing on partition-coefficient data spanning logP values from below zero to above five. Building on this materials-chemistry foundation, the article reviews organ-specific pharmaceutical evidence across the systems most developed for drug testing — liver (drug-induced liver injury, DILI), kidney (drug-induced kidney injury, DIKI, and transporter-mediated clearance), heart (torsadogenic and structural cardiotoxicity), blood-brain barrier (CNS drug permeability), gut (absorption and peristalsis-dependent differentiation), and immune-competent chips (cytokine release syndrome and immuno-oncology) — before detailing the regulatory landscape on both sides of the Atlantic, market trajectory, the organoid-versus-chip comparison, and the technical and institutional barriers, including chemistry-rooted ones, that continue to separate OoC technology from routine pharmaceutical use. As of mid-2026, no organ-chip has achieved full FDA qualification, though several sponsors have submitted chip-derived data directly within individual investigational new drug (IND) applications, and one hepatotoxicity chip has cleared the first of three ISTAND qualification stages. This article argues that organ-chip material and surface chemistry is not a peripheral fabrication detail but a first-order determinant of whether a given platform's pharmacological data can be trusted, and that organ chips are best understood today not as animal-testing replacements but as a maturing, chemistry-constrained, regulator-engaged evidentiary category whose near-term value is organ-system-specific and accrues fastest where substrate chemistry has been matched to the physicochemical properties of the compound class under study.

Abstract: 1-Isobutylpurine-2,6-diones possess a broad spectrum of pharmacological activities, highlighting their relevance in the search for new biologically active agents. In this study, we report the synthesis of a series of novel thietane-containing 1-isobutylpurine-2,6-dione derivatives. A crucial aspect of this work is the detailed stereochemical and conformational analysis of the thietanyl substituent. For the first time, the unambiguous assignment of axial and equatorial protons within the thietane ring was achieved using 2D NMR spectroscopy, exemplified by a comprehensive study of the starting substance. Furthermore, the newly synthesized compounds were evalu-ated for their antiplatelet activity, revealing inhibition of platelet aggregation exceed-ing that of acetylsalicylic acid. Based on structural analogy to established antiplatelet agent, we hypothesize that the observed biological effect is mediated via the inhibition of the glycoprotein IIb/IIIa (GPIIb/IIIa) receptor complex. These findings demonstrate that the incorporation of a thietane fragment into the 1-isobutylxanthine scaffold yields promising candidates for the development of novel GPIIb/IIIa-targeted an-tiplatelet therapeutics.

Abstract: Cold Spray (CS) technology has established itself as a versatile solid-state deposition process with significant potential for both repair applications and manufacturing of bulk parts. This review examines recent advances in CS, emphasizing its unique ability to deposit metals and composites without melting, thereby minimizing oxidation, thermal distortion, and residual stresses. These advantages have positioned CS as a technique with all the credentials for being used within industry for restoring damaged components, especially, where high microstructural quality and mechanical integrity are critical. This review paper synthesizes current knowledge on different coatings/deposits produced by CS, the processing of present-day and future metals/alloys by cold spray, and specific requirements for industrial applications employing this technology. Additionally, it highlights the growing use of CS as an additive manufacturing (AM) technology, where layer-by-layer deposition enables the fabrication of complex geometries, gradient materials, and hybrid structures. Advances in cold spray additive manufacturing (CSAM) technology and deposition strategies are also discussed. Remaining challenges, including in-situ monitoring, predictive modeling, and the need for standardized qualification protocols, are identified. Overall, this review underscores CS transformative role in enabling high-performance repairs and novel AM strategies, while outlining future research directions to expand its industrial adoption.

Abstract: Background/Objectives: Poly(xylitol sebacate) (PXS) is a biodegradable, biocompatible hyperbranched polyester capable of self-assembling into nanoparticles for hydrophobic drug delivery. Building on our prior physicochemical characterization of PXS nanoparticles, this study evaluated whether curcumin-loaded PXS nanoparticles (LNP) can deliver curcumin to colorectal cancer (CRC) cells and enhance its anticancer activity relative to free curcumin. Methods: Unloaded (UNP) and curcumin-loaded PXS nanoparticles were fabricated by nanoprecipitation and characterized by dynamic light scattering (DLS) and scanning electron microscopy (SEM). Four CRC cell lines (HCT116, HT29, SW480, SW620) were treated with free curcumin, UNP, or LNP at an equivalent curcumin concentration of 20 μg/mL for 48 h; viability was measured by CellTiter-Blue® assay, and cell morphology and curcumin cellular association were assessed by phase-contrast and fluorescence microscopy. Results: Nanoparticles fell within the target 100–200 nm range (LNP: 171.04 nm; UNP: 212.40 nm at 24 h) and remained colloidally stable for 48 h (159–203 nm). SEM confirmed spherical morphology for both formulations, and UNP were not cytotoxic at 20 μg/mL. LNP produced substantially greater viability reduction than free curcumin across all lines: SW480 and SW620 decreased to ~30% viability (~70% reduction), HT29 to ~60% (~40% reduction, despite minimal response to free curcumin), and HCT116, the most resistant line, to ~70% (~30% reduction). Fluorescence imaging suggested closer cellular association of LNP-delivered curcumin, although the signal was modest and not quantified. Conclusions: PXS nanoparticles are an effective, biodegradable carrier that enhances the cellular delivery and anticancer activity of curcumin in CRC cells, supporting further development of this hyperbranched polyester platform for cancer drug delivery.

Abstract:

The ongoing climate crisis, caused by the annual release of 37 billion metric tons of CO₂ emissions, is putting pressure on the advancement of Carbon Capture and Storage (CCS) and Direct Air Capture (DAC) technologies. Metal–Organic Frameworks (MOFs), with their high surface areas and modular pore topologies, present a very attractive class of sorbents for CO₂ capture; however, it currently remains computationally prohibitive to explore their extensive chemical design space. Herein, we provide a thorough evaluation of how machine learning (ML) (as an emerging technology) has played an increasing role in furthering our understanding of CO₂ capture from MOFs. Through an organized investigation, we provide evaluations of the latest generation of models across four key areas: application at a process level, mechanistic interpretable modelling; physically relevant descriptors, and predictive performance metrics. Recent work with Machine Learning Interatomic Potentials (MLPs) shows that traditional assumptions about rigid frameworks are being challenged by the fact that diffusion properties and adsorption thermodynamics are heavily influenced by the flexibility of the framework. The use of physics-informed descriptor engineering yields R² values of 0.81-0.97 across gas species and pressure regimes, while the generative nature of Deep Reinforcement Learning and transformer-based architectures has been shown to allow for the inverse design of frameworks with high affinities for gas species. The trend in this sector is moving towards optimization of multiple scales simultaneously and integrating processes to achieve an optimized property prediction. Current work with machine learning is focusing on using a combination of material properties and operational indicators (such as how much gas is recovered through pressure swing adsorption) to make predictions. As these techniques improve, there will be a similar need for a design that is both physically informed and understandable, thus allowing for a link between molecular discoveries and water-stable materials that have been experimentally verified and are suitable for use in commercial applications.

Abstract: The rational design of inorganic phosphors with targeted emission wavelengths is challenging because luminescence depends on strongly coupled structural, electronic, and excitation-dependent factors. Machine-learning studies in this area often prioritize predictive accuracy without systematically evaluating descriptor reproducibility and physical interpretability. Here, we develop a physics-guided explainable machine-learning framework that combines multi-method feature selection, descriptor stability analysis, and physicochemical interpretation for emission-wavelength prediction. A curated dataset of 2327 single-dopant phosphor compositions, initially represented by 125 physicochemical descriptors, was refined to 46 physically meaningful descriptors. Twelve complementary feature-selection methods were evaluated using eight stability metrics and 10-fold cross-validation. Pearson correlation and ANOVA-F, which are mathematically related univariate criteria for measuring linear association, identified the same seven-descriptor subset with complete 10/10 fold-level reproducibility. The resulting Random Forest model achieved a mean cross-validated R² = 0.9308, MAE = 7.78 nm, and RMSE = 22.55 nm. The seven-descriptor model retained essentially the same predictive performance as the best fully reproducible 24-descriptor model while reducing descriptor dimensionality by about 71% relative to that model and by about 86% relative to the full physically meaningful candidate space. On the independent test set, RF and GB achieved R² values of 0.9192 and 0.9023, respectively. SHAP analysis, descriptor ablation, interaction analysis, and complementary feature-importance methods consistently identified the same descriptor hierarchy. The ionic radius of the emission-center site was the dominant predictor, followed by excitation source and dopant valency. These results suggest four practical considerations for phosphor screening, namely activator-site compatibility, dopant oxidation state, host chemical environment, and excitation conditions. The results show that descriptor selection should consider not only predictive accuracy but also reproducibility, compactness, generalizability, and physical interpretability.