Additive manufacturing of multi-responsive materials is opening new opportunities in a wide range of applications, including information storage, security, and sensing. Herein, complex structures enabling both the encoding and encryption of information in three dimensions (3D) are achieved by combining photo- and pH-responsive chromophores, spiropyran and phenolphthalein derivatives, respectively, within a single ink formulation. To this end, a multi-wavelength digital light processing (DLP) system is employed to fabricate initially colorless structures using a 405 nm wavelength LED to trigger the photopolymerization process. In parallel, a 365 nm wavelength LED integrated into the same system can induce locally controlled isomerization of spiropyran to the colored merocyanine, enabling information encoding in 3D in a layer-by-layer fashion. The stored information can be reversibly encrypted on demand via pH variation. The pH-responsive chromophore, phenolphthalein, enables modulation of optical contrast, rendering the encoded patterns temporarily unreadable. This work opens new pathways toward engineering multi-responsive functionality in complex 3D architectures.

Developing a highly sensitive and specific carcinoembryonic antigen (CEA) detection method is of great significance for rapid screening, monitoring, and evaluation of tumors. This study developed a sandwich sensor based on dual recognition modes (molecular imprinting and aptamer) and dual detection modes (persistent luminescence and colorimetry) for CEA detection, effectively improving the selectivity and detection accuracy of the sensor. Firstly, magnetic molecularly imprinted polymers (m-MIPs) targeting CEA were synthesized with Fe3O4 nanoparticles as the magnetic core, and the persistent luminescent nanoparticles (PLNPs) ZnGa2O4:Cr[3+] (ZGC) were immobilized onto the m-MIPs to construct the m-MIPs/ZGC as the first recognition probe. Subsequently, MOF-5@PP ~ Apt was synthesized as the second recognition probe. During detection, the high selectivity of imprinted cavities was utilized to achieve efficient capture of the target molecule CEA. Based on the high affinity between aptamers and CEA, the sandwich-structured m-MIPs/ZGC@CEA@MOF-5@PP ~ Apt was formed. Due to the overlap between the absorption range of MOF-5 (220-275 nm) and the excitation range of ZGC (220-300 nm), the persistent luminescence intensity of ZGC at 700 nm is weakened by competitive excitation absorption. The decrease in persistent luminescence intensity exhibits a good linear correlation with CEA concentration. In addition, the color change intensity of phenolphthalein in the supernatant under weakly alkaline conditions was also well correlated with CEA concentration. The results indicate the linear ranges for persistent luminescence and colorimetric determination were 1-2000 ng L[- 1] (R[2] = 0.9967), corresponding to a detection limit of 0.45 ng L[- 1], and 2.5-50 µg L[- 1] (R[2] = 0.9865), corresponding to a detection limit of 0.95 µg L[- 1], respectively. This dual-recognition and dual-signal sensing platform integrates the merits of m-MIPs, aptamers and PLNPs, offering a reliable dual-modal strategy for accurate CEA quantification in complex samples.

Over the years, synthetic indicators have been the choice for acid-base titrations. However, due to environmental and safety concerns, the search for natural compounds that can act as acid-base indicators is important. This study aims to identify an eco-friendly natural indicator from the Dioscorea alata L. yam species. Dried D. alata yam was ground into a coarse powder and extracted with an acidified methanol-water mixture for 15 minutes. The resulting extract was tested for colour changes in the pH range from 1 to 12. An acid-base titration was carried out using the D. alata extract as the indicator. The results were compared with synthetic standard indicators (phenolphthalein, methyl orange, and methyl red). An acid-base test paper strip was developed using the D. alata extract to determine the acidity or basicity of an aqueous solution. The results showed a clear color change in the extract from red to dark mustard when the pH changed from 1 to 12, and the UV-Vis spectrum showed a hypsochromic to bathochromic shift when the pH of the medium changed from acidic to basic. The D. alata L. yam extract performed well in strong acid-strong base, strong base-weak acid, and strong acid-weak base titrations, and it showed sharp color changes at the endpoints of the titrations, which coincided with the endpoints obtained from the standard synthetic indicators. The acid-base test paper strips developed were red in colour; they remained red in the acidic medium and changed to yellow in the basic medium. Thus, the D. alata yam extract has potential for application as a natural and safe alternative to the conventional acid-base indicators currently used in chemical laboratories.

This study reports an integrated dual-signal microfluidic immunosensor for point-of-care detection of ovalbumin-specific IgE (OVA-sIgE) in interstitial fluid. A pH-responsive composite material, ZIF-8 encapsulating phenolphthalein and surface-conjugated with antimouse OVA-sIgE (ZIF-8@PP∼Abs), was synthesized and characterized. Structural and elemental analyses confirmed the successful synthesis and antibody functionalization, while the composite retained strong alkaline-triggered colorimetric response due to ZIF-8 decomposition and subsequent phenolphthalein release. Carbon dots (CDs) show concentration-dependent fluorescence, which is effectively quenched by ZIF-8@PP∼Abs. A paper-based chip coimmobilized with CDs and OVA antigen enabled simultaneous colorimetric and fluorescent detection. The colorimetric pathway operates as a "turn-on" system through alkaline-induced color change, while the fluorescent pathway functions as a "turn-off" system via CDs quenching by ZIF-8@PP∼Abs. Quantitative analysis using the green channel─identified as the most sensitive through RGB decomposition─showed linear responses across 0.06-8.00 ng/mL OVA-sIgE, with detection limits of 0.026 ng/mL (colorimetric) and 0.032 ng/mL (fluorescence). The dual-signal design, featuring built-in cross-verification, demonstrates high reliability through favorable spike-and-recovery results. ROC analysis shows AUC values of 0.9999 for both signals, with a significant reduction in false positives. To achieve operational integration, a custom-designed negative-pressure-driven microfluidic chip was developed, incorporating all necessary steps into a negative-pressure valve-controlled microfluidic chip. The chip demonstrated robust fluid handling, repeatable operation, and user-friendly functionality. The integrated sensor exhibited excellent selectivity, strong anti-interference capability against common interstitial fluid constituents. This work presents a practical, accurate, and reliable platform for decentralized allergy testing, merging advanced nanomaterials, dual-mode transduction, and microfluidic engineering.

Calcium leaching increases the hydraulic concrete material's porosity and the diffusion coefficient, thereby jeopardizing engineering safety. Fly ash and silica fume are commonly used mineral admixtures in hydraulic concrete, and their effects on the material's leaching characteristics, especially its microstructural and transport properties, require further investigation. In this study, calcium leaching tests were conducted on cement paste (CP), silica fume-cement paste (SF), and fly ash-cement paste (FA) using a 6 mol/L ammonium chloride solution to accelerate the leaching process. Subsequently, a series of quantitative and qualitative analyses was performed on the deteriorated specimens, including phenolphthalein indicator spraying, X-ray diffraction (XRD), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM). Additionally, the diffusion coefficients of the material at different locations were calculated and analyzed. The results show that partially replacing cement with silica fume or fly ash increases the initial porosity, gel pore content, and initial diffusion coefficients. After 28 days of leaching, compared to the initial values, the porosity increases in the 0-4 mm layer from the leached surface were 83.6% for CP, 11.0% for SF, and 39.0% for FA. The diffusion coefficients increased by factors of 14.3 (CP), 6.1 (SF), and 13.6 (FA), indicating enhanced resistance to leaching. The primary reason for this is that the reactive silica in the admixtures undergoes a pozzolanic reaction with the calcium hydroxide generated by cement hydration, producing additional calcium silicate hydrate (C-S-H) gel, which reduces the capillary pores that would otherwise result from calcium hydroxide decomposition.

Cyclodextrins (CDs) exhibit concentration-dependent aggregation in aqueous solution governed by substitution chemistry, hydration, and intermolecular interactions. In this study, the aggregation behaviour of β-cyclodextrin (β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), and sulfobutyl ether-β-cyclodextrin (SBE-β-CD) was systematically investigated in the presence of monovalent (K[+]) and divalent (Ca[2+]) electrolytes using dynamic light scattering, conductivity, surface tension, and phenolphthalein inclusion measurements. Under salt-free conditions, β-CD showed pronounced aggregation driven by intermolecular hydrogen bonding, SBE-β-CD displayed coexistence of molecular and aggregated populations consistent with its charged substituents, and HP-β-CD remained largely dispersed due to steric and hydration effects. Electrolyte addition modified aggregation trends in a valency-dependent manner. K[+] produced moderate changes consistent with electrostatic screening, whereas Ca[2+] induced stronger and time-dependent aggregation effects. Conductivity measurements reflected electrolyte-dependent modification of the ionic environment, while surface tension data supported changes in aggregation state. Phenolphthalein inclusion assays demonstrated that electrolyte-induced aggregation correlates with variations in effective cavity accessibility. These results provide comparative physicochemical insight into how substitution pattern and ion valency influence aggregation and host-guest behaviour of cyclodextrins in aqueous solution.

In this work, a comparative analysis on dye bleaching capacity of porphyrin-core dendrimers (Pf-Ds) of two different sizes (first and second generations) in high water content media is carried out. First, a series of new second-generation compounds were synthesized and characterized by absorption and fluorescence spectroscopies. These dendrimers showed high solubility in hydro-alcoholic solutions, allowing the transport of free-base tetraphenyl-porphyrin in a medium where, without branching, it would not be soluble. In addition, the triplet states were also characterized by transient spectroscopy, obtaining high intersystem crossing quantum yields. The singlet oxygen quantum yields were estimated and comparable to those of typical porphyrins, which demonstrates that sensitizing capacity of the core is not affected by the extent of dendritic branching. In order to compare the performance of these compounds in pollutant treatment, the effect of branching size on the bleaching of phenolphthalein as a model dye was evaluated. All the compounds showed high photodegradation efficiency via singlet oxygen after short irradiation times under visible LEDs. However, as a general trend, it was observed that first-generation compounds were more effective than second-generation ones. Based on quenching experiments, such results were interpreted in terms of the intermolecular interactions occurring between the reactants and the role played by the length of the dendritic arm.

Current society is facing the global surge in obesity rates, making people more aware of the importance of body weight control and increasing the consumption of weight-loss supplements due to their over-the-counter status. However, certain producers have intentionally adulterated supplements with prescription weight-loss drugs without label declaration, necessitating suitable analytical methods for routine analysis of illegal weight-loss compounds in health supplements. In this study, a rapid, effective, and reliable liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of 11 wt-loss compounds in three supplement forms (i.e., hard capsule, soft capsule, and tea powder). A suitable analytical procedure was selected via the optimization of LC-MS/MS parameters and sample preparation conditions. The samples were ultrasonicated with methanol, and the extracts were cleaned up using dispersive solid-phase extraction with C18 and carbon sorbent. The method was validated for specificity, linearity, method detection and quantification limits, precision, and accuracy, producing good satisfaction. The method was applied to analyze 82 health supplement samples collected from the Vietnamese market, in which seven samples were found to be adulterated with at least one of the target compounds. Sibutramine, phenolphthalein, and benzylsibutramine were detected in 7/82, 5/82, and 2/82 samples with concentration ranges of 0.44-16.4, 0.54-2.14, and 0.14-1.43 mg/g, respectively. These results indicated the method applicability to the quality control of health supplements in developed and emerging countries.

This paper presents a dataset of accelerated carbonation test results for 48 concrete mixes with varying binder compositions, water-to-binder ratios, and air-entrainment levels. The dataset includes raw and processed data on material properties, exposure conditions, carbonation depth measurements, and derived carbonation rates. Concrete mixes were prepared using four cement types with different proportions of ground granulated blast-furnace slag (GGBS), ranging from 0% to 72%. Each mix was tested in both air-entrained and non-air-entrained versions. Accelerated carbonation was performed in controlled chambers at approximately 3% CO₂ concentration. Carbonation depth was measured at multiple intervals up to 84 days using phenolphthalein indicator. Additional data cover fresh and hardened concrete properties. The dataset is openly available in Zenodo and can be reused for benchmarking mix designs, validating service-life models, and comparing accelerated and natural carbonation performance.

A dual-mode electrical-optical nanocomposite hydrogel is developed by integrating carboxyl-modified upconversion nanoparticles (UCNPs-COOH) and quaternized chitosan (CQAS) into a polyacrylamide (PAAm) covalent network. The hydrogel exhibits high optical transparency (>90% in the visible region), excellent mechanical properties (fracture strain of 1742%, tensile strength of 0.85 MPa, toughness of 6.57 MJ/m[3]), and robust adhesion to various substrates. The synergistic covalent-noncovalent hybrid network enables efficient energy dissipation, while CQAS-enhanced dispersion of UCNPs significantly improves upconversion luminescence intensity and stability, as evidenced by prolonged fluorescence lifetime from 0.564 ms to 0.691 ms at 539 nm. Leveraging distinct electrical and optical signal transduction pathways, the hydrogel functions as a highly sensitive resistive strain sensor with multistage gauge factors up to 13.85 and excellent cyclic stability over 1200 loading-unloading cycles at 100% strain for human motion monitoring. It also serves as a ratiometric optical pH sensor over a broad range (pH 1-13) based on phenolphthalein-sensitized upconversion luminescence, with excellent repeatability. By integrating real-time resistance responses with optical readouts within a single soft material, this work demonstrates a reliable dual-mode sensing strategy for simultaneous mechanical and chemical monitoring, holding promise for wearable electronics, smart healthcare, and environment-responsive sensing systems.

Self-propelled directional liquid transport enables power-free reagent delivery with minimal liquid volumes and flexible loading sites, making it a compelling platform for advanced microreaction systems. Among various strategies, bioinspired asymmetric re-entrant microstructures are particularly effective, as they harness amplified Laplace pressure gradients and capillary forces to achieve efficient directional fluid manipulation. Despite these advances, fluidic manipulation remains largely tethered to 2D surfaces, in which reaction volumes are constrained by the accessible liquid thickness, severely limiting scalability, throughput, and controllability. Inspired by the highly efficient 3D capillary confinement observed in porous natural tissues, we report an open microreaction platform that integrates cellular microlattices with asymmetric re-entrant microstructures, enabling the synergistic realization of unidirectional liquid transport and programmable reaction volume control. A programmable layer-reduction 3D printing strategy is developed to fabricate these microarchitectures with high fidelity, yielding outstanding capillary performance, including an ethanol rise height of 39.9 mm and unidirectional transport reaching 40.0 mm. The versatility of the platform is further demonstrated through physical liquid mixing and phenolphthalein-based acid-base neutralization reaction. Collectively, these results underscore the strong potential of this bioinspired strategy for realizing volume-controlled, directional capillary microreaction systems in advanced chemical and biological applications.

The growing demand for high-security anticounterfeiting and traceable information encryption materials requires systems capable of generating irreversible "access records" to prevent replication and tampering. Conventional fluorescent materials, such as organic dyes and rare-earth compounds, are limited by complex synthesis, low luminescence efficiency, and reversible response behaviors that compromise traceability. Herein, two copper(I) iodide hybrid materials, denoted as 1D-Cu and 2D-Cu, are reported, which undergo an ethanol-triggered irreversible structural transformation from 1D-Cu to 2D-Cu. This transformation induces a pronounced photoluminescence redshift from weak green emission (539 nm, PLQY = 0.15%) to intense orange-red emission (639 nm, PLQY = 30.25%), accompanied by markedly enhanced thermal stability. Structural and spectroscopic analyses reveal that the superior stability and optical performance of 2D-Cu arise from strong intracluster Cu···Cu interactions (2.577-2.928 Å) and reinforced organic-inorganic interfacial interactions. Exploiting this irreversible transition, a dual-mode anticounterfeiting platform is developed. The visible-light mode enables self-erasable information display using phenolphthalein, while under UV excitation, the permanent fluorescence transformation serves as a visual and irreversible record of unauthorized access on paper substrates. This work demonstrates the potential of irreversible structural transitions in copper halide materials for high-security anticounterfeiting and traceability applications.

The ConcreteCARB dataset provides a comprehensive repository of 903 high-resolution images of concrete surfaces evaluated using the phenolphthalein test for carbonation detection. This data was collected under controlled laboratory conditions and aims to support artificial intelligence applications in civil engineering, especially in structural health monitoring tasks. The images are systematically organized into two distinct classes: "Carbonated Samples" and "No Carbonation Presence," enabling binary classification approaches. All samples were manually tested, split, and visually labelled by expert engineers to ensure reliable ground-truth classification, in accordance with standardized procedures. The dataset includes images of concrete prism elements fabricated with varying mix designs, incorporating different water-cement ratios and additives, such as industrial silica waste and natural admixtures derived from Opuntia ficus-indica. The specimens were subjected to natural atmospheric carbonation conditions for 180 days, and their carbonation fronts were revealed by phenolphthalein staining. The samples were then split manually with a chisel and hammer, and photographic documentation was performed with a Samsung SM-S901U1 smartphone using predefined settings to ensure consistency and quality across the dataset. ConcreteCARB is intended for researchers, engineers, and data scientists working on machine learning, deep learning, and computer vision solutions for concrete diagnostics. It provides valuable training and benchmarking data for the development of automated detection, classification, and segmentation models for carbonation damage assessment. Furthermore, the dataset can serve as a foundational tool for cross-comparative studies on the efficacy of AI techniques in materials degradation analysis. The openly accessible nature of the dataset through a public repository supports reproducibility and encourages the extension of AI applications in concrete durability and sustainability studies.

Effective control of SO2 emissions is crucial for air quality and environmental protection. Non-regenerable dry flue gas desulfurization remains attractive for small boilers, low-temperature flue gas treatment, and water-scarce regions. However, developing highly active sorbents remains a critical challenge for practical applications. Sodium carbonate (Na2CO3) offers a theoretical SO2 uptake nearly 1.6 times that of sodium bicarbonate (NaHCO3), but its low reactivity and rapid surface passivation limit its practical application. Here, we report a simple, low-energy surface modification in which a trace amount of phenolphthalein (0.1 mol%) markedly enhances the SO2 uptake by ∼530 % and increases sorbent utilization from 9.8 % to 62.5 %. The phenolphthalein-modified Na2CO3 (PP-Na2CO3) exhibited optimal performance at 130-150 °C under 7.9-14.7 vol% water vapor, showing robust adaptability under high SO2 concentrations. Moreover, the optimized PP-Na2CO3 achieved an SO2 uptake 1.84 times higher than that of NaHCO3. These enhancements overcome the long-standing limitations of Na2CO3, underscoring its potential for practical application in low-temperature dry flue gas treatment. Based on structural and compositional characterization, mechanistic analysis shows that this enhancement is derived from the rearrangement of phenolphthalein molecules on the Na2CO3 surface, which introduces polar oxygen-containing functional groups and thereby forms a temperature-responsive functional active interface that enhances SO2 and H2O adsorption. Meanwhile, the interface promotes the formation of a Na2SO3-dominated product layer with a reticulated-wrinkled morphology, which mitigates pore blockage, enhances accessibility of unreacted cores, and thereby substantially improves sulfur conversion efficiency and sorbent utilization. This work provides insights for designing high-performance sorbents with functional organic-inorganic interfaces.