Chemistry and Materials Science

Abstract: Nitrogen-doped graphene-like materials exhibit high catalytic activity and stability in the oxygen reduction reaction. Theoretical studies of catalytic activity based on DFT calculations typically assume that the reaction proceeds via an inner-sphere mechanism involving the chemisorption of an oxygen molecule. In this work, using grand-canonical DFT calculations we demonstrate that, in an alkaline medium, an outer-sphere reaction mechanism, initiated with an electron transfer to a solvated O2 molecule near the surface, is energetically more favorable. On N-doped graphene containing graphitic nitrogen atoms, the reaction proceeds via a 4e mechanism due to a significant reduction in the chemisorption energy of the *OH intermediate, whereas on pristine graphene, the reaction terminates after two electron transfers.

Abstract: Electrocoagulation (EC) treatment of mine tailings water transfers metals, metalloids, and suspended minerals into sludge, creating a secondary waste stream whose resource potential requires rigorous qualification. This structured review synthesizes 105 eligible studies selected from 850 Scopus records published during 2006–2026; search and screening records are documented in Supplementary Material S1. Evidence from mine-affected waters is distinguished from non-mining wastewater studies, whose recovery outcomes require matrix-specific validation before transfer to tailings-derived sludge. Investigated pathways include sludge conditioning, adsorption, catalysis, construction materials, pigments, and selective mineral recovery. Across these applications, aqueous contaminant removal, solid-phase formation, functional performance, and environmental safety represent distinct evidentiary requirements. We propose a source–phase–function–risk (SPFR) framework linking feedwater and electrode provenance, mineralogical and chemical phase identity, application-specific performance benchmarks, contaminant mobility, and life-cycle and techno-economic comparisons. SPFR provides a transparent, staged qualification approach rather than a validated predictive score. Key research priorities include dry-solid mass balances, phase-resolved characterization, product durability, realistic leaching and aging tests, and consistent functional-unit comparisons. These requirements support evidence-based decisions on responsible resource recovery from EC sludge generated during mine tailings water treatment.

Abstract: Azo-dye electropolymerization produces functional electrode films, but links between electrochemical activation, reactive intermediates, molecular coupling and growth remain incompletely established. A structured literature search, complemented by backward and forward tracking, yielded an audited core of 33 primary studies published between 2012 and 2026. Thirty-one include sensing or electroanalytical applications and 11 use methyl orange as a precursor; none in this core primarily targets direct removal of an azo-dye pollutant through its own electropolymerization. The evidence indicates that activation and coupling pathways depend on molecular structure, solution acidity, electrode material and polarization programme. A provisional physicochemical framework separates transport, adsorption, electrochemical activation, effective intermediates, competing reactions and material accumulation. Conservation laws are distinguished from phenomenological closures; current is not equated with polymer growth. Material-balance, mechanistic-validation and energy-efficiency criteria are proposed, together with a staged experimental roadmap toward predictive modeling and assessment of water-treatment applications.

Abstract: Electronic tongue signals provide objective measures of taste-related responses, but their quantitative correspondence with human perceptual intensity remains insufficiently characterized. This study developed a psychophysically calibrated electronic tongue framework for quantitative bitterness evaluation and sweetness-induced modulation. Concentration-dependent responses to quinine hydrochloride, berberine hydrochloride, and iso-α-acid followed logarithmic relationships, with coefficients of determination of 0.991, 0.910, and 0.984, respectively. By integrating these instrumental relationships with psychophysically derived sensory bitterness references, compound-specific conversion models were established to translate electronic tongue signals into human sensory bitterness intensity. Independent validation yielded mean absolute percentage errors of 6.02%, 10.76%, and 7.14%, respectively. Increasing sucrose concentration from 0% to 2% and 8% generally attenuated bitterness-related electronic tongue responses, with compound-dependent differences. The proposed framework provides a quantitative bridge between electronic tongue signals and human bitterness perception and extends instrumental bitterness evaluation toward taste-interaction systems.

Abstract: Bisphenol A (BPA, 2,2-bis(4-hydroxyphenyl) propane) is a synthetic intermediate used worldwide in the industrial production of polycarbonates and epoxy resins. Its extensive use has led to systemic accumulation across various environmental matrices, leading to significant toxicological concerns resulting from its well-documented role as an endocrine disruptor associated with metabolic disorders, reproductive abnormalities, and oncogenic risks. Consequently, worldwide, the need to develop robust and highly sensitive analytical tools for the detection of trace amounts of BPA has proven essential for both environmental monitoring and the protection of public health. Building on our previously reported MnPc-His-CPE biomimetic sensor, this study presents the design, electrochemical characterization, structural analysis, and electroanalytical evaluation of a novel cobalt phthalocyanine–histidine-modified carbon paste electrode (CoPc-His-CPE), with particular emphasis on elucidating the role of the central metal ion in metallophthalocyanine-based sensors for trace-level BPA determination. To our knowledge, this constitutes the first systematic structural and mechanistic investigation of a CoPc-His-CPE platform for BPA sensing. The integration of histidine into the CoPc-CPE matrix induces a synergistic effect that significantly enhances the electrochemical performance relative to conventional configurations. The structural and morphological properties of the resulting composite were investigated by FT-IR, UV–Vis spectroscopy, and SEM, while charge transfer dynamics were elucidated through cyclic voltammetry, chronocoulometry, and electrochemical impedance spectroscopy (EIS). Under optimized square wave voltammetry (SWV) conditions, the sensor exhibited a broad linear range from 8.10-8 to 4.10-5 mol L⁻¹, with a detection limit of 4.78 nmol L⁻¹ (S/N = 3). The sensor further demonstrated selectivity and stability (RSD = 5.0%, n = 10), and its practical utility was validated through the analysis of real environmental samples, yielding recovery rates ranging from 91.10% to 106.40%.

Abstract: The oxygen reduction reaction (ORR) is a critical process in fuel cells, yet its slow kinetics necessitates efficient and cost-effective catalysts. Anion exchange membrane fuel cells (AEMFCs) offer a promising platform for ORR electrocatalysis, as the alkaline environment enables the use of non-precious metals and carbonaceous materials. Herein, we utilize a simple, solid-state, reagent-free, and one-step synthesis of silver nanoparticle-decorated laser-induced graphene (Ag@LIG) via direct CO\(\mathrm{_2}\) laser writing on a polyimide film coated with an edible silver leaf. The laser treatment simultaneously converts the polymer into a porous three-dimensional graphene network and incorporates metallic silver nanoparticles (\(\sim\)5--50 nm) into the carbon matrix. X-ray photoelectron spectroscopy confirms the metallic nature of the incorporated silver and a marked increase in nitrogen content from ~2 at.% in pristine LIG to ~11 at.% in Ag@LIG, with pyrrolic nitrogen as the dominant configuration. Electrochemical characterization demonstrates that Ag@LIG exhibits significantly enhanced ORR activity compared to pristine LIG, with a \(\sim\)50 mV positive shift in onset potential and a predominantly four-electron pathway over the entire potential range, indicating efficient reduction of O\(\mathrm{_2}\) to OH^- with minimal peroxide (HO\(\mathrm{_2^-}\)) formation. The enhanced performance likely arises from the interplay between metallic silver nanoparticles and the nitrogen-doped carbon support, where the nitrogen-rich carbon matrix provides favorable O\(\mathrm{_2}\) adsorption sites and the embedded Ag nanoparticles promote O--O bond cleavage. This work highlights the potential of the solid-state laser approach for producing Ag-carbon hybrid electrocatalysts with promising ORR performance for alkaline fuel cells.

Abstract: Lithium-ion battery degradation limits the performance, safety, cost, and service life of consumer electronics, electric vehicles, industrial systems, and grid-energy storage. This review synthesizes the electrochemical, mechanical, thermal, and transport processes that govern battery ageing and links them to health assessment, lifetime prediction, and battery-management decisions. A mechanism-to-decision framework is used to distinguish degradation mechanisms, degradation modes, and cell-level outcomes. The review examines solid-electrolyte-interphase growth, lithium plating, particle fracture, cathode reconstruction, transition-metal dissolution, electrolyte decomposition, separator damage, and electrode cross-talk. These processes contribute to lithium loss, active-material loss, electrolyte depletion, stoichiometric imbalance, impedance growth, capacity fade, and power fade. The effects of temperature, state of charge, depth of discharge, current rate, ageing history, chemistry, and cell design are assessed, with emphasis on coupled mechanisms, spatial non-uniformity, path dependence, and knee-point ageing. The review also discusses state-of-health estimation, remaining-useful-life prediction, mitigation strategies, and digital-twin approaches. Capacity alone is insufficient because similarly aged cells may differ in resistance, safety margin, and future lifetime. Future research should prioritize realistic pack-level datasets, uncertainty-aware prediction, standardized testing, operando diagnostics, transferable models, and decision-oriented battery management.

Abstract: The present study investigates the effect of synthetic diamond nanoparticles as functional modifiers of NiCoP coatings, simultaneously addressing their corrosion resistance and bifunctional HER/OER electrocatalytic performance on Fe-steel substrates. A direct comparison between electroless and electrodeposition routes is presented. The corrosion behaviour of the coatings was evaluated ex situ in 1 M and 6 M KOH electrolytes to assess their stability under both operating and accelerated degradation conditions. The as-prepared and alkali-treated coatings were characterized by potentiodynamic polarization measurements, X-ray diffraction (XRD), field-emission scanning electron microscopy coupled with energy-dispersive spectroscopy (FE-SEM/EDS), and X-ray fluorescence (XRF) analysis. In addition, their bifunctional electrocatalytic performance toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) was evaluated. The results demonstrate that synthetic diamond incorporation influences the corrosion behaviour of NiCoP coatings; however, the magnitude and direction of this effect depend strongly on both the deposition route and the electrolyte concentration. Furthermore, co-electrodeposition combined with synthetic diamond nanoparticles emerges as a promising approach for developing PGM-free, diamond-modified NiCoP composite coatings on commercially available Fe-steel substrates, providing an effective balance between coating microstructure, corrosion resistance, and bifunctional electrocatalytic performance.

Abstract: Cadmium contamination in fruits is a relevant food-safety concern because of its toxicity, environmental persistence, and potential transfer from agricultural soils to edible plant tissues. This study developed a screen-printed carbon electrode modified with graphene oxide and cysteamine (SPCE/GO–cysteamine) to determine Cd(II) by square-wave anodic stripping voltammetry (SWASV). Two surface-modification routes, GO-cysteamine and GO-rGO-cysteamine, and GO concentrations of 0.1, 0.2, and 0.5 mg m⁻¹ were compared by cyclic voltammetry. The direct GO-cysteamine route at 0.2 mg mL⁻¹ gave the best electrochemical response and was selected for Cd(II) determination. Raman spectroscopy and scanning electron microscopy were used to characterize the graphene-based materials employed during surface optimization. In standard solutions, the platform showed a linear response from 1 to 10 µg L⁻¹, with a sensitivity of 11.2865 µA (µg L⁻¹)⁻¹, R² = 0.9892, a limit of detection of 0.98 µg L⁻¹, and a limit of quantification of 2.97 µg L⁻¹. Fortified Kent mango and Hass avocado digestates also showed concentration-dependent responses, with R² values of 0.9799 and 0.9788, respectively, and relative standard deviations below 5%. These results demonstrate the feasibility of the SPCE/GO–cysteamine platform for Cd(II) determination in digested fruit matrices and support its further development as a portable screening approach for food-quality control.

Abstract: The desire to employ wearable electronics and smart textiles has been excitingly driving researchers to design flexible devices for energy conversion and storage. Carbon cloth has been recommended as an electrode skeleton because of its flexibility, chemical stability, safety, environmental friendliness, affordability, excellent electrical conductivity, and high mechanical strength. This review sheds light on recent advances and challenges in CC-based hybrid electrodes for supercapacitors. Four general strategies have proven efficacious in augmenting the electrochemical performance. Firstly, treatment of the CC surface via chemical, thermal, or electrochemical activation processes aims to introduce pores and oxygen functional groups that increase specific surface area and wettability. Secondly, the combination of transition metal compounds, conductive polymers, and carbon forms on hybrid electrodes utilizes both charge storage mechanisms of EDLC and pseudocapacitors. Thirdly, optimization of synthesis parameters is a prime practice to obtain favorable morphology and crystallinity. Fourthly, the integration of current collectors, electrodes, and electrolytes by conformal coating of active materials on carbon microfibers preserves the 3D nature of the cloth. Last but not least, analysis of cycling stability receives a great deal of attention for practical considerations. By following these strategies, CC-based hybrid supercapacitors hit the apex of their performance, scoring colossal specific capacitances, energy and power densities, and stability.

Abstract: Sodium-ion batteries (SIBs) are promising due to abundant, low-cost sodium, however, the larger ionic radius of Na⁺ severely hinders high-capacity, long-life anode materials. Molybdenum disulfide (MoS₂) offers a high theoretical capacity but suffers from intrinsically poor electrical conductivity and severe volume fluctuation during cycling, necessitating effective modification strategies. A composite consisting of ZIF-8-derived carbon and MoS₂ is successfully synthesized via co-precipitation, in-situ pyrolysis, and subsequent hydrothermal treatment using ZIF-8 as a precursor. The composite exhibits an increased specific surface area of 10.26 m2·g^-1 and a reduced particle size compared with pristine MoS₂. Electrochemical tests show that ZnS@NC@MoS₂ delivers an initial discharge specific capacity of 523.3 mAh·g^-1 at 100 mA·g^-1 with an initial Coulombic efficiency of 75.3%, outperforming pristine MoS₂. In rate capability tests, a specific capacity of 277.8 mAh·g^-1 is achieved at a high current density of 5000 mA·g^-1. The capacitive contribution increases with scan rate, reaching 87.75% at 8 mV·s^-1. The enhanced electrochemical performance is attributed to the porous structure of the ZIF-8-derived carbon, which effectively suppresses MoS₂ agglomeration, improves electrical conductivity, and facilitates Na⁺ diffusion. This work provides a promising strategy for designing high-performance anode materials for sodium-ion batteries.

Abstract: Iron–air batteries (IABs) represent a novel energy storage system based on the iron redox reaction. They offer several advantages such as high energy density (≈ 200 Wh kg⁻¹), environmental friendliness, and low cost, with broad application prospects in large-scale long-duration energy storage, peak-valley power regulation, and emergency power supply. However, hydrogen evolution side reactions easily occur during IAB charging, reducing Coulombic efficiency. Additionally, passivation of the iron anode limits reaction kinetics and cycle life. Thermal imbalance in air batteries also reduces stability. Existing research has addressed these issues by focusing on optimizing electrolyte compositions, additives, structural stability of the iron anode, and material design. We systematically review the progress and application of IABs as energy storage devices in the steel industry, with a systematic outlook on future research directions and applications.

Abstract:

Green hydrogen production via water electrolysis is a cornerstone of the sustainable energy transition. However, the oxygen evolution reaction (OER) remains the kinetic bottleneck, limiting overall efficiency. Nickel-iron (NiFe) based catalysts are among the most promising non precious materials for the OER in alkaline media, offering high activity and low cost. Nevertheless, their practical application at industrially relevant current densities (>100 mA cm^–2) is hindered by several challenges: structural degradation, uncontrolled surface reconstruction, metal dissolution (corrosion), particularly Fe leaching, and the ambiguous role of the fundamental mechanisms. This review critically discusses the current understanding of these degradation pathways, the influence of preparation methods, the interplay between Ni and Fe redox chemistry, and strategies for enhancing long-term stability. Future directions for designing durable NiFe OER electrocatalysts are also outlined. The paper also considered a strategy for investigating new catalysts using electrochemical and non-electrochemical techniques, devoted to young scientists interested in this field. In the Outlook and Perspective, the key drawback is present and the possible strategy for improvement is discussed.

Abstract: Bifunctional electrocatalysts that offer low overpotentials, robustness, and potential compatibility with scalable fabrication routes are essential for effective alkaline water splitting. In this study, a porous nickel microparticle/polymer interlayer was applied to commercial nickel foam via screen printing, serving as a framework for the solvothermal growth of cobalt-based oxide/hydroxide nanostructures. The optimized electrode demonstrated strong bifunctional performance in 1 M KOH, requiring only 61 mV for the hydrogen evolution reaction and 241 mV for the oxygen evolution reaction at a current density of 10 mA cm^-2. In comparison, the control electrodes, such as those with cobalt directly deposited on unmodified nickel foam and altered nickel foam substrates without cobalt, exhibited poorer overall performance. Although the cobalt-modified unaltered nickel foam exhibited a higher C_dl-derived apparent electrochemical surface area, the cobalt-modified screen-printed electrode achieved the best ECSA-normalized HER and OER responses, indicating that the enhancement in activity was not solely due to the capacitive surface area. The increased integrated redox charge suggests a greater contribution from electrochemically accessible Co/Ni redox-active species, while impedance analysis supports a more favorable apparent interfacial response under the tested HER- and OER-relevant conditions. Long-term chronopotentiometry and post-stability SEM supported stable bifunctional operation.

Abstract: Interconnector geometry strongly affects gas transport, polarization loss, and pressure drop in planar solid oxide fuel cells (SOFCs). In this study, four interconnector configurations were investigated for an anode-supported planar SOFC, including one conventional straight-rib interconnector and three connected-rib interconnectors, namely circular-rib(CI), rectangular-rib(RI), and triangular-rib(TI) designs. A three-dimensional multi-physics model coupling electric field, flow field, species transport, and temperature field was established and validated against experimental polarization data of the conventional straight-rib cell. To ensure a fair comparison, all interconnectors were designed with the same interconnector-electrode contact area. The effects of rib configuration on electrical performance, overpotential components, reactant distribution, velocity distribution, and pressure drop were systematically analyzed. At 800 °C, the peak power densities of CI-SOFC, RI-SOFC, and TI-SOFC increased by 4.9%, 9.7%, and 11.7%, respectively, compared with SI-SOFC. The connected-rib interconnectors mainly reduced cathode-side activation and concentration overpotentials by improving oxygen redistribution beneath the ribs. Among the four configurations, the TI-SOFC showed the highest power density and the strongest under-rib transport enhancement, while the RI-SOFC provided a better compromise between flow uniformity and pressure drop.

Abstract: Aerosol-assisted chemical vapor deposition (AACVD) was used to prepare thin film of heterojunction WO3/MnO2 onto FTO glass substrate. The WO₃/MnO₂ heterojunction thin film exhibited a monoclinic WO₃ structure characterized by a nanorod-like shape and substantial interfacial bonding. The detected surface area of WO₃/MnO₂ thin film is 33.14 μm², while the values of R_a and R_q are 24.8 nm and 31.3 nm, respectively, which are higher than pure MnO₂ while lower than pure WO3 thin films. The UV-Vis spectra demonstrated extensive absorption in the visible to near-infrared range. The absorption spectrum of UV-vis (200–900 nm) displayed a distinct absorption edge under 400 nm. The band gab of the pure WO3 thin film equals 2.79 eV. Whereas, an effective band gap of WO3/MnO2 was observed equals 1.51 eV, that is significantly smaller than that of the individual oxides (MnO₂ = 4.04 eV and WO₃ = 2.79 eV). PL verified robust interfacial electronic interaction. The investigation of PEC performance exhibited the best performance and the greatest photocurrent under illumination than either pure component. Additionally, a good enhancement and improvement in charge separation due to the combining catalytic MnO2 thin film with photoactive WO₃ owing to effective charge transfer and decreased recombination.

Abstract: Cortisol, as a crucial biomarker reflecting psychological stress and physiological status, requires rapid and sensitive detection for health assessment and disease diagnosis. Conventional methods are time-consuming, operationally complex, and costly, limiting their use for point-of-care testing. This study reports a flexible, aptamer-based capacitive biosensor that exploits alternating current electrokinetics for ultrafast detection of cortisol in small-volume samples. Aptamers are immobilized via Au-S self-assembly on gold interdigitated electrodes on a PET substrate, and ACEK-induced fluid motion and dielectrophoresis rapidly enrich cortisol at the electrode interface, producing measurable interfacial capacitance changes ΔC/C₀. Experimental results demonstrate detection limits of 0.412 ng/mL in PBS and 0.337 ng/mL in artificial sweat, with response times within 1 minute and excellent linear response across 1-1000 ng/mL concentrations. Requiring only 10 μL of sample, the sensor exhibits good repeatability, specificity, and interference resistance, making it suitable for rapid cortisol level detection. To enhance detection stability, this study designed and integrated a microfluidic chip, enabling efficient sample delivery and stable detection. The system demonstrates strong interference resistance, revealing potential applications in health management and disease monitoring.

Abstract: Research on the effect of ammonium chloride (NH₄Cl) electrolyte on graphene nanosheet (GNS) electrodes derived from candlenut shells (Aleurites moluccana (L.) Willd) as primary battery cathodes has been conducted. GNS was synthesized via pyrolysis and modified with NH₄Cl to produce G–N 0.5 M, G–N 1.0 M, G–N 2.0 M, and G–N 3.0 M samples. The materials were characterized using XRD, SEM-EDX, and electrical measurements at 0.5–1.5 V. XRD results show peaks at 2θ ≈ 25° and 44.27° corresponding to C(002) and C(100) planes, while G–N samples exhibit new diffraction peaks at (111), (200), (220), (311), (222), and (400), indicating NH₄Cl incorporation. SEM analysis reveals a transition from layered GNS morphology to more wrinkled and agglomerated structures with increasing NH₄Cl concentration, supported by EDX showing decreasing carbon content and the presence of chlorine (up to ~5.9%). Electrical conductivity increases significantly from commercial battery to GNS and further to G–N samples, reaching ~1.30 S·cm⁻¹ for G–N 2.0 M, along with energy density (~605 Wh·kg⁻¹) and power density (~605 W·kg⁻¹). These results indicate that NH₄Cl modification enhances electrochemical performance and highlights the importance of electrolyte variation in optimizing GNS-based electrodes for primary battery applications.

Abstract: 6061 aluminum alloy is lightweight and has good thermal conductivity, while 304 stainless steel possesses excellent mechanical properties and corrosion resistance; both have broad application prospects in cooling circuits. Propylene glycol coolant shows great potential in liquid cooling systems due to its low toxicity and good antifreeze properties. However, during operation, galvanic corrosion may occur when the two metals come into direct contact within the coolant, thereby threatening system safety and service life. This study focuses on 6061 aluminum alloy, 304 stainless steel, and their galvanic couples. Using electrochemical testing, SEM, 3D confocal microscopy, and XPS to systematically investigate their self-corrosion and galvanic corrosion behavior in propylene glycol coolant at pH values of 4.8, 6.8, and 8.8. The results indicate that 6061 aluminum alloy is more sensitive to pH changes; its corrosion resistance first increases and then decreases as pH rises, with the least corrosion occurring at pH = 6.8 and the most severe at pH = 4.8. 304 stainless steel exhibited lower corrosion rates at pH 6.8 and 8.8, but corrosion significantly worsened at pH 4.8. For the 6061 aluminum alloy/304 stainless steel couple, the galvanic current first decreased and then increased with rising pH, while the galvanic potential first increased and then decreased. The 6061 aluminum alloy consistently acted as the anode, and the 304 stainless steel consistently acted as the cathode, with the highest sensitivity to galvanic corrosion observed at pH 4.8. XPS analysis shows that under different pH conditions, the corrosion products of 6061 aluminum alloy are Al(OH)3 and Al2O3, while the main components of the passivation film on 304 stainless steel remain unchanged.

Abstract: Anthracycline agents, principally doxorubicin and daunorubicin, are widely used in oncology yet carry a narrow therapeutic index and pronounced interindividual pharmacokinetic variability that exposes patients simultaneously to the risk of subtherapeutic dosing and cumulative cardiotoxicity. Conventional therapeutic drug monitoring (TDM) based on periodic venous sampling and offline high-performance liquid chromatography cannot resolve the sub-minute concentration dynamics that determine organ-specific drug exposure. Electrochemical aptamer-based (EAB) sensors couple nucleic-acid aptamers, self-assembled monolayers, and methylene blue redox reporters on gold microelectrodes to convert binding-induced conformational changes into real-time, reagent-free electrochemical signals. Recent advances in this field fall into five areas: signal interrogation strategies, from kinetic differential measurement to calibration-free Fourier-transform impedance spectroscopy (FFT-EIS); interface engineering including nanostructured electrodes and AI-guided aptamer design; in vivo multi-compartment pharmacokinetic monitoring and closed-loop feedback drug delivery; the mechanisms of in vivo signal drift alongside antifouling countermeasures spanning hydrogel barriers, zwitterionic brushes, and xenonucleic acid backbone substitution; and FDA premarket pathways and clinical translation, including Premarket Approval requirements and the emerging Real-Time Clinical Trial (RTCT) framework. In live rodents, dual-compartment monitoring has resolved a reproducible 30–60 minutes plasma-to-ISF lag for doxorubicin at 12-second temporal resolution; calibration-free FFT-EIS interrogation achieves inter-animal coefficients of variation below 12% without individual pre-calibration; and xenonucleic acid backbone substitution has extended continuous in vivo operation to seven consecutive days. Three gaps still separate rodent proof-of-concept work from chemotherapy patients: clinical-context validation, tumor microenvironment calibration, and anthracycline-specific XNA aptamer design.