Liquid organic hydrogen carriers offer a dense platform for hydrogen storage, yet their deployment is hindered by catalyst deactivation and energy demand. This review provides a mechanism-focused synthesis connecting atomic-scale electronic descriptors to catalyst formulation and reactor performance. We revisit Brønsted–Evans–Polanyi relationships, volcano trends, and electronic modulation as conditional tools for interpreting C-H activation. These principles rationalize alloying strategies: Pt-Sn illustrates activity–stability trade-offs; Pt-Pd tailors adsorption energetics; supported Pt-Ir illustrates preparation-dependent dispersion. We also examine metal–support interactions on oxides, mesoporous silicas, and carbon matrices that enable confinement and spillover. Integrating these insights, we outline a multi-scale design perspective linking electronic descriptors to surface kinetics, framing durability as a central criterion. The review concludes with opportunities in data-driven discovery, operando deactivation mapping, and process optimization, emphasizing green-chemistry priorities of efficiency, selectivity, reduced critical-metal use, and long-term stability.
Early, reliable detection of α-synuclein (αSN) is critical for Parkinson's disease diagnosis, yet antibody-based assays remain limited by sensitivity, matrix effects, and cost. We report a label-free aptamer–gold nanoparticle nanobiosensor (G12Apt@AuNP) for non-invasive αSN detection in saliva. Molecular docking identified F5R1 as the aptamer with the most favorable predicted binding affinity; a dodeca-guanine (G12) was appended to provide colloidal stabilization and to control conjugation and orientation on the AuNP surface. Interaction with αSN monomers, oligomers, and fibrils produced a concentration-dependent plasmonic red-shift arising from αSN-induced nanoparticle aggregation. Conditions were optimized by Taguchi design and ANOVA. Across 8 pM–8 μM, the platform achieved an 8 pM detection limit and a 0.8 nM–0.8 μM linear range for 24 h aggregated αSN, comparing favorably with reported label-free optical aptasensors. It showed high selectivity against related proteins and detectable responses in spiked saliva at 4 nM, supporting development toward clinical synucleinopathy detection.
The melting of finite-sized two-dimensional (2D) clusters is ubiquitous in nature and technology. Here, we reveal a sequential surface-to-bulk-to-surface redistribution of defects in large clusters, whereas defects remain predominantly surface-localised in small crystallites. Using molecular dynamics simulations of colloids with tunable interactions, which serve as molecular-like model systems, we study the spatial distribution of defects and observe pronounced size-dependent defect behaviour during melting. Our results shed light on the role of cluster size in defect formation and melting across systems ranging from atomic clusters to colloidal assemblies.
Developing patient-friendly and non-invasive topical drug delivery systems is essential for improving therapeutic efficacy and patient compliance. In this study, ketotifen (KTF)-loaded microemulgels (mu EGs) were formulated using biocompatible ingredients for enhanced topical delivery. Microemulsion (mu E) systems composed of castor oil, Emulan EL, isopropanol, and water with varying surfactant/co-surfactant ratios (S-mix) were developed to systematically investigate the influence of formulation composition on microstructural characteristics and topical drug delivery performance and subsequently gelatinized using PEG-6000 and Poloxamer 407 to achieve controlled skin permeation. Pseudoternary phase diagram analysis identified optimized formulations containing similar to 11% castor oil, similar to 14% water, and similar to 75% S-mix, capable of incorporating similar to 2.5 wt% KTF. Conductivity and viscosity analyses confirmed phase transitions from water-in-oil (w/o) to oil-in-water (o/w) systems through a bicontinuous phase. Transmission electron microscopy and dynamic light scattering revealed monodisperse nano-sized droplets with sizes ranging from similar to 49-95 nm for mu Es and similar to 61-120 nm for KTF-loaded mu EGs. Ex vivo permeation studies using rabbit skin in a Franz diffusion cell at pH 7.4 demonstrated enhanced permeation, with mu EGs achieving >90% drug release after 12 h. The improved performance was attributed to their nanoscale droplet size and higher viscosity, and the combined physicochemical and permeation analyses established a clear relationship between formulation composition, microstructural evolution, and topical permeation behavior. These findings provide mechanistic insight for the rational optimization of mu E-based topical drug delivery systems.
Extracellular enzymes from plants and microorganisms drive soil nutrient recycling, yet how mineral interfaces regulate enzyme activity remain unclear. Here, we investigated two extracellular phosphatases, from plant Ipomoea batatas and fungus Aspergillus niger, interacting with quartz, goethite, and illite. Enzyme kinetics, molecular modeling, and infrared spectroscopy were combined to resolve interfacial mechanisms controlling catalysis. For plant phosphatase, despite comparable adsorbed fractions, activity loss was 17% greater on illite than on goethite or quartz. Stronger inhibition by illite was consistent with direct surface interactions that suppressed enzyme flexibility, whereas water-mediated interactions on goethite and quartz caused minor perturbations of catalytic core. For fungal phosphatase, adsorption was up to 3-fold higher on illite than on goethite or quartz, but activity loss differed by only about 10%. Illite promoted rigid β-sheet–rich conformation with reduced α-helix and random-coil content, while weaker binding on goethite and quartz produced transient structural perturbations that caused activity loss.
