The extensive use of azo food colorants has heightened public health concern, underscoring the need for advanced sensing methods to accurately quantify these compounds in food products. Herein, a ratiometric fluorescent sensor employing dual-emission carbon dots (DC-CDs) is developed for the sensitive detection and differentiation of azo colorants. The DC-CDs are synthesized from tris (hydroxymethyl) aminomethane and 2, 5-diaminobenzenesulfonic acid via a solvothermal method. At a wavelength interval of 120 nm, the synchronous fluorescence spectrum of DC-CDs displays two well-defined emission peaks at 320 nm and 470 nm. Upon addition of azo food colorants, the fluorescence signals at 320 and 470 nm are both quenched due to the combined effects of inner filter effect (IFE) and fluorescence resonance energy transfer (FRET). Accordingly, DC-CDs provide the limits of detection (LODs) of 43 nM, 56 nM, 76 nM and 49 nM for sunset yellow (SY), tartrazine (Tar), allura red (AR) and azorubine (AZ), respectively. Furthermore, mixtures of azo food colorants can be effectively distinguished through the combined use of hierarchical cluster analysis (HCA), principal components analysis (PCA) and linear discriminant analysis (LDA). For practical applications, DC-CDs are encapsulated into an electrospun film to fabricate a smartphone-assisted sensing platform for the on-site determination of azo food colorants in real commercial food samples, yielding satisfactory recoveries (96.7%-103.1%) with relative standard deviations below 5.92%. This work integrates dual-emission synchronous fluorescence analysis with an electrospun film platform, offering a sensitive and feasible approach for the on-site analysis of azo food colorants.

Rapid interleukin-6 (IL-6) monitoring is essential for the early diagnosis and management of inflammatory and oncological conditions. This study reports a label-free impedimetric immunosensor based on a ternary poly(azo-BBY)-AuNP/rGO nanocomposite synthesized via a single-step electrochemical process. The platform utilizes dissolved oxygen as an intrinsic redox probe, precluding the need for external mediators. Morphological characterization confirmed a synergistic architecture where gold nanoparticles are encapsulated within the polymeric matrix and covered by a reduced graphene oxide veil, reducing charge-transfer resistance by over 90%. The immunosensor achieved a detection limit of 2.51 pg mL-1 with a linear range between 5 and 30 pg mL-1. A thermodynamic investigation via the Freundlich isotherm revealed a dual-stage adsorption mechanism and a steric "gate effect". Selectivity assays demonstrated high specificity, including the competitive displacement of IL-6 by the IL-1 receptor antagonist (IL-1RA). Practical utility was validated in cell culture, yielding results statistically equivalent to the ELISA gold standard. Operational stability was established for 4 days within a 95% confidence interval (97.2%-115.1%). These findings support the proposed platform as a proof-of-concept label-free immunosensor for IL-6 monitoring.

Trivalent chromium exhibits a dual nature. It acts as a necessary micronutrient for lipid and carbohydrate metabolism at low levels in the body, but causes dangerous genotoxic harm at higher thresholds. Hence, precise tracking of trace trivalent chromium is absolutely essential. Compounding this, its intracellular detection remains highly obstructed by paramagnetic fluorescence quenching and a deficiency in selective probes. Addressing this material and analytical challenge, this work reports the development of an ultrasensitive "turn-on" fluorogenic chemosensor utilizing a novel azo-based dye, 2-[(E)-(4-methylphenyl)diazenyl]phenol (MPDP). Unlike traditional methods restricted to microgram boundaries, this newly developed strategy establishes a wide dynamic linearity descending to an extraordinary femtogram detection limit. The probe operates via a chelation-enhanced fluorescence (CHEF) pathway at pH 9.0, successfully validating chromium(III) quantification in plant matrices. Furthermore, integration of density functional theory (DFT) and non-covalent interaction (NCI) analysis successfully maps out the precise, thermodynamically favored octahedral coordination mechanics driving its extreme metal selectivity.

To address the critical limitations of traditional photothermal-responsive epoxy-based shape memory polymers (ESMPs), such as poor compatibility and cyclical instability, a series of side-chain azobenzene (Azo)-functionalized linear ESMPs (EPDm) were successfully synthesized via chemical bonding. Highly rigid 4-aminoazobenzene (Azodm) units were covalently integrated into the Bisphenol A-type epoxy backbone as functional photo-responsive side chains. Systematic characterizations confirmed that the glass transition temperature (Tg) of the EPDm polymers could be precisely tuned from 41.53 °C to 53.26 °C by adjusting the Azodm content. Benefiting from the proposed homogeneous covalent architecture, the EPDm films exhibited superior photothermal sequential behavior and remarkable shape memory stability despite a slight reduction in tensile strength (≈10-12 MPa). Under 365 nm UV irradiation, the pre-stretched EPDm10 specimen achieved a rapid macroscopic bending angle of over 150° within 15 s, driven exclusively by the trans-to-cis molecular photoisomerization of the Azo side chains well below the matrix Tg. Furthermore, standard shape memory cycles demonstrated excellent shape fixity (Rf > 98%) and recovery (Rr > 95%) ratios, alongside exceptional anti-fatigue performance with minimal strain variance (≈5%) over consecutive cycles. This work establishes a robust and high-efficiency molecular design strategy for photo-thermally sequentially responsive shape memory polymers, offering immense potential for smart actuators and flexible electronics.

The presence of pharmaceuticals in aquatic ecosystems implies the need for efficient and sustainable treatment processes for their removal. This paper reports an innovative adsorption-regeneration process of a heat-resistant montmorillonite/sand composite (Mnt/sand) used to remove phenazopyridine (PHY) from aqueous media. Unlike other adsorption-thermolysis processes, which mostly use fine clay particles, this composite entraps the adsorptive Mnt phase within a fine sand matrix to improve the performance of the adsorbent. A maximum adsorption of 8.98 mg g[-1] was achieved using the total weight of the Mnt/sand composite, whereas 44.90 mg g[-1] was calculated on the basis of the weight of the active Mnt phase only. Kinetic studies revealed that the adsorption process occurs via pseudo-second-order kinetics (R [2] = 0.997), suggesting that the rate-limiting step in the process is due to surface interactions. The equilibrium data followed the Langmuir isotherm model, indicating that monolayer adsorption occurred on homogeneous sites, whereas thermodynamic calculations revealed that the process was spontaneous and endothermic (ΔG° < 0, ΔH° > 0). Furthermore, the Mnt/sand composite was tested under continuous flow conditions using a fixed-bed column. In the case of the breakthrough run with a nominal C 0 = 20 mg L[-1], Q = 2 mL min[-1] and m = 3.0 g, breakthrough was observed at 33.75 min, with a breakthrough capacity of 0.439 mg g[-1]. The kinetic parameters obtained from the Thomas model are k Th = 5.14 × 10[-3] L mg[-1] min[-1], q Th = 0.758 mg g[-1], and R [2] = 0.963, representing an efficiency of the bed usage of 57.9% compared with the theoretical saturation capacity. The experiments on thermal regeneration revealed highly efficient restoration of the adsorption capacity of the material at approximately 550 °C, with stable performance throughout multiple cycles (87-90%). From the point of view of computational research, the adsorption of PHY molecules on Mnt is energetically favorable (E ads = -0.1273 hartree = -334.25 kJ mol[-1] = -3.46 eV), accompanied by structural modification of PHY, which could be helpful for the thermal degradation of PHY.

Heparin, a polyanionic anticoagulant, is widely used clinically but requires neutralization to restore normal blood coagulation. Protamine sulfate (PS) is the standard antidote, yet limitations exist. Herein, a polycationic, cavity-containing pillar[6]arene macrocycle (P12+) demonstrates superior heparin neutralization in physiological media compared to its lower-valency analog P10+, and performance comparable to PS. MTT assays reveal low toxicity of the P12+, suggesting feasibility for in vivo use. Dynamic light scattering reveals that P12+ forms nanoscale complexes below 400 nm, smaller than PS-heparin aggregates. Remarkably, P12+ exhibits enhanced neutralization of low-molecular-weight heparin, a known limitation of PS. Additionally, heparin detection is achieved via a host-guest indicator displacement assay (IDA) using methyl orange (MO). UV-vis studies show ∼80% MO release with P12+, compared to ∼40% with P10+ in the presence of heparin. This response is detectable in undiluted human plasma for P12+, whereas P10+ shows a suitable response in 5% diluted plasma. A fluorescence-based IDA enables sensitive detection down to 0.11 U/mL, below the therapeutic range (0.80-2.00 U/mL). Molecular dynamics simulations support these findings, revealing that weaker host-guest interactions and favorable electrostatics in P12+ facilitate efficient MO release.

Pharmaceutical salts are commonly used to enhance the bioavailability of poorly water-soluble drugs. The maximum solubility in water and the physical stability of a salt are closely linked to its pHmax, the pH at which both the free form (acid or base) and the salt can coexist. However, several aspects related to pHmax are only partially addressed or unexplored: (1) before salt screening, which usually consumes significant materials and efforts, whether pHmax can be predicted based on molecular properties; (2) whether salt disproportionation proceeds via a solid-state or water-mediated mechanism; and (3) whether disproportionation risk can be graded systematically and predicted. In this work, the relationship between pHmax and the physical properties of the basic compounds was examined, and a regression model was constructed based on their correlations. The pHmax values of 106 monosalts for 35 basic drugs were compiled from the literature. In the data set examined, the pHmax is strongly correlated with the pKa of the drug (2-10), but not significantly with the pKa of the counter-acid (-8 to 5), and is slightly influenced by the molecular weights of the drug and counter-acid. Accordingly, before salt screening, pHmax of a monosalt can be predicted as a function of the drug pKa and the relevant molecular weights. Across a pH range of 1-11, for the 106 monosalts studied, 74% of the predicted pHmax values were found to be within experimental errors. To determine whether disproportionation between pharmaceutical salts of basic drugs and basic excipients is a solid-state reaction or not, differential scanning calorimetry (DSC) is performed. The results showed that a solid-state reaction did not occur even at high temperatures where the excipient either melted or was liquefied above its glass transition temperature. Disproportionation risk levels were systematically defined based on development requirements and were exemplified using model HCl salts (sertraline, prazosin, phenazopyridine, and pioglitazone) across a wide pHmax range. The risk level shows a strong correlation with the pH difference between the equilibrium pH of the excipient (pHee) and the pHmax of the salt. Notably, the risk level increases more sharply with the pH difference (pHee - pHmax) for highly hygroscopic excipients. A prediction workflow for disproportionation risk level is proposed based on the above correlation and the self-disproportionation type of pharmaceutical salts.

Finding effective materials for the removal of pollutants from wastewater has become an essential requirement in environmental protection and the development of advanced water-treatment technologies. In this study, Ti3C2T x -MXene was synthesized using two methods (i.e., sol-gel and hydrothermal). The influence of synthesis parameters, including etching agent (i.e., LiF and NaF), temperature (i.e. 38, 80 and 90 °C), and reaction time (i.e., 3 and 7 days), on the structural characteristics and pollutant-removal performance of MXene was systematically investigated. The synthesized samples were evaluated for the removal of dye and pharmaceutical contaminants, including methylene blue (MB), tetracycline (TC), carbamazepine (CBZ), and phenazopyridine (PhP). The results revealed that the sample synthesized using LiF (i.e., LTi2) as an etchant at 90 °C possessed the highest specific surface area and exhibited higher adsorption efficiency compared to other samples. At an initial concentration of 10 ppm, LTi2 removed more than 93% of MB and 88% of PhP within 60 min through adsorption. At a concentration of 40 ppm, adsorption efficiencies of approximately 48%, 29%, and 18% were obtained for MB, TC, and CBZ, respectively. Under subsequent visible-light irradiation, further pollutant removal was observed, resulting in total removal efficiencies exceeding 98% for MB and 93% for PhP at 10 ppm, while overall removal efficiencies of 59%, 64%, and 37% were achieved for MB, TC, and CBZ, respectively, at 40 ppm. These findings demonstrated that careful control of the synthesis conditions was an effective strategy for tailoring the MXene structure and improving its adsorption-dominated and visible light assisted pollutant removal performance.

In this work, a series of N-allyl-5-arylidene-rhodanine derivatives was prepared and their reactivity evaluated as dipolarophiles in 1,3-dipolar cycloaddition reactions. Cycloadducts of series 5 were obtained using sarcosine and 5-nitroisatin as precursors, while reactions with sarcosine and 2-pyridinecarboxaldehyde afforded new 2-pyridyl-substituted spiro derivatives (series 7). All compounds from both series were fully characterized and screened for their in vitro anticancer activity against the following five human cancer cell lines: A2780 (ovarian carcinoma), A549 (lung adenocarcinoma), MDA-MB-231 (breast carcinoma), NCI-N592 (small-cell lung cancer), and A431 (epidermoid carcinoma). Several derivatives exhibited pharmacologically relevant IC50 values, with compounds 5b and 7b demonstrating noteworthy antiproliferative activity in A549 cells, a standard model for non-small cell lung carcinoma. The apoptotic potential of the most active compounds was further confirmed by Annexin V/PI assays in A549 cells. Using baicalein as a reference inhibitor, both compound series were also subjected to molecular docking studies targeting the human enzyme 15-lipoxygenase-2 (h15-LOX-2), implicated in cancer-related pathways. In general, a consistent trend was observed between the antiproliferative activity of the compounds and their predicted inhibition of h15-LOX-2, as inferred from docking analysis of 28 structures, including the 10 final allyl rhodanine-based compounds and their required precursors. To further evaluate target engagement, molecular dynamics (MD) simulations were performed for the most active derivatives, providing mechanistic insight into binding-pocket rigidification and conformational stability. In addition, in silico ADMET predictions were carried out to assess the developability profile of the lead candidates. The integrated chemical synthesis, biological evaluation, and computational modeling provided key insights into the reactivity, bioactivity, and structure-activity relationships of the synthesized compounds.

Carmoisine (CM), an azo dye, imparts vibrant red color when added to the food, beverage, cosmetic and pharmaceutical products. The excessive intake of CM causes various health effects and hence it is essential to develop appropriate methods for the determination and quantification of CM in food samples. In this current work, a rapid detection and analysis of CM was performed via cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques by harnessing sodium dodecyl sulfate modified composite sensor (SDSMCS). The morphological features and elemental composition of bare carbon nanotube graphite composite sensor (BCNGCS) and SDSMCS surfaces were compared and the difference between the working sensors was assessed. The active surface area was computed as 0.031 cm[2] for BCNGCS and 0.049 cm[2] for SDSMCS surfaces by employing CV technique. Key insights into the charge transfer process involved in the oxidation of CM was obtained by electrochemical impedance spectroscopy (EIS). The modified sensor demonstrated improved electrochemical features at optimal experimental conditions. The analysis validated that the electro oxidation of CM proceeds through adsorption-controlled kinetics at the surface of SDSMCS and exhibited a significantly low limit of detection (LOD) of 0.009 µM by CV and 0.073 µM by DPV technique, in the linear range of 0.1 µM to 1.1 µM and 0.1 µM to 0.9 µM, respectively. The attributes like reproducibility and repeatability of the developed SDSMCS were evaluated and the respective relative standard deviation (RSD) of 4.95% and 4.90% verified that the fabricated sensor is reliable for detecting CM in various commercial food samples with a recovery rate exceeding 97%. Surfactant- reformed carbon-based sensors provide a cost-effective and reliable platform that aligns with the evolving trends in field of electrochemical sensing.

Phenazopyridine is a urinary analgesic widely available as both a prescription and over-the-counter medication, yet its appropriate clinical use, safety profile, and limitations remain poorly understood among patients and clinicians alike. This activity examines the pharmacology, approved indications, pharmacokinetics, dosing recommendations, adverse effects, and monitoring considerations associated with phenazopyridine. Particular attention is given to the drug's role as an adjuvant therapy in uncomplicated urinary tract infections, its contraindications in renal and hepatic impairment, and the risks associated with prolonged or inappropriate use. The activity also addresses the importance of patient education regarding the drug's symptomatic, not anti-infective, properties. By completing this activity, clinicians will be better equipped to counsel patients appropriately, recognize serious adverse effects, such as methemoglobinemia and hemolytic anemia, and apply evidence-based guidelines to optimize the safe and effective use of phenazopyridine in clinical practice.

A bryophyte survey was conducted on Santa Maria Island in 2019, taking advantage of the MOVECLIM-AZO project expedition to the Island, while adding collections in different sites. The standard collection follows the Global Island Monitoring Scheme (GIMS) protocol for bryophytes across three altitudinal levels (16, 200 and 400 m a.s.l.) and substrates, while the other specimens were collected opportunistically to improve the known dataset of bryophyte occurrences in Santa Maria. Opportunistic sampling was carried out guided by taxonomic expertise, while visiting different locations between 31 and 464 m a.s.l. and exploring diverse substrates. The survey resulted in the collection of 85 species and 810 specimens (occurrence records), obtained from 264 events. This research presents a dataset that expands current knowledge about bryophyte diversity on Santa Maria Island and supports future studies.

The chemistry of vitamin C adducts was revisited to investigate their pH sensitivity, photophysical properties, optical behavior, and assess their potential as eco-friendly pH indicators. In this study, a series of ascorbic acid adducts were synthesized through a straightforward, high-yield method. Their acid-base responsiveness is driven by a reversible protonation-deprotonation process between the hydrazineyl and azo groups, causing observable color changes. Analysis of substituent effects demonstrated that strong electron-withdrawing groups like nitro (-NO2) significantly impact the electronic structure, particularly when located at the ortho or para positions of the aromatic ring. Solvatochromic studies revealed that the ortho-nitro adduct 3(b) and para-nitro adduct 3(d) exhibited positive solvatochromism, with their absorption wavelengths increasing in more polar solvents. Notably, 3(b) displayed a consistent yellow color with λmax around 396 nm across solvents, indicating its structural stability and solvent-independent optical behavior, making it a robust and versatile pH indicator. Halochromic studies in aqueous media revealed pronounced bathochromic shifts for both 3(b) and 3(d) under alkaline conditions. The 3(b) exhibited a color change from yellow to dark purple (λmax = 534 nm), while the 3(d) transitioned from colorless (λmax = 361 nm) to dark rosewood (λmax = 472 nm). Spectrographic analysis determined that 3(b) had a pKa of 8.99 and 3(d) a pKa of 10.68. The band gap analyses conducted under both alkaline and acidic conditions provide detailed insights into the optical properties and electronic transitions of the most promising adducts, 3(b) and 3(d). The optical band gap energies obtained from UV-Vis spectroscopy, Eg(optical) and Eg(Tauc), showed strong agreement with the electrochemically measured band gap, Eg(electronic). These findings were further corroborated by computational results from DFT (B3LYP/6-311 + G(d,p)), where the theoretically calculated band gaps, Eg(DFT), validated the experimentally derived values and provided additional information through frontier molecular orbital (FMO) analysis, indicating the presence of an efficient push-pull electronic system throughout the adduct structures. Correlation of DFT outputs with Tauc-plot analyses clarified the nature of the electronic transitions, including π → π*, n → π*, and intramolecular charge-transfer (ICT) processes, and determined whether these transitions were direct or indirect, and whether they were symmetry-allowed or forbidden. Biochemical assays further supported the proposed neutral proton-transfer mechanisms operating under both acidic and basic conditions for the promising adducts. Thermal analysis divulged thermal stability up to 210 °C. Acid-based titration tests showed that 3(b) and 3(d) produced sharp and accurate endpoints comparable to the standard methyl red indicator, while 3(c) did not exhibit a reliable color transition. Given their green origin, tunable structures, and visual responsiveness, these ascorbic pH indicators hold promising candidates for sustainable applications in food coloration, cosmetics, and medical diagnostics.