Ratiometric fluorescence probe based on boric acid-modified carbon dots and alizarin red for sensitive and rapid detection of glyphosate.

By combining boric acid-modified carbon dots (p-CDs) and alizarin red (ARS), a double emission probe p-CDs@ARS with fluorescence at 410 nm and 600 nm is designed for the detection of glyphosate. When Cu2+ is added, it binds with ARS to cause ARS release from p-CDs@ARS, which decreases the fluorescence at 600 nm. However, in the presence of glyphosate, glyphosate competes to the binding of Cu2+, releasing ARS to bind with p-CDs again. Therefore, the fluorescence of 600 nm recovers. Based on this, the fluorescence of 410 nm and 600 nm act as the reference and response signal, respectively, achieving the ratiometric fluorescence detection of glyphosate. The linear range of glyphosate detection is 0.5-50 µM with a limit of detection at 0.37 µM which is well below the maximum residue limit for glyphosate in food. When the probe is used to detect the glyphosate residue in Pearl River water and cucumber, the detection results are well consistent with those detected by HPLC. The established method based on p-CDs@ARS has the advantages that the assembly of ratiometric fluorescence probe is simple, and the detection speed is fast. Additionally, a typical INHIBIT logical system has been successfully constructed based on glyphosate, Cu2+, and the fluorescence signal of p-CDs@ARS.

Alizarin attenuates oxidative stress-induced mitochondrial damage in vascular dementia rats by promoting TRPM2 ubiquitination and proteasomal degradation via Smurf2.

BACKGROUND: Alizarin (AZ) is a natural anthraquinone with anti-inflammatory and moderate antioxidant properties. PURPOSE: In this study, we characterized the role of AZ in a rat model of vascular dementia (VaD) and explored its underlying mechanisms. METHODS: VaD was induced by bilateral common carotid artery occlusion. RESULTS: We found that AZ attenuated oxidative stress and improved mitochondrial structure and function in VaD rats, which led to the improvement of their learning and memory function. Mechanistically, AZ reduced transient receptor potential melastatin 2 (TRPM2) expression and activation of the Janus-kinase and signal transducer activator of transcription (JAK-STAT) pathway in VaD rats. In particular, the reduction in the expression of TRPM2 channels was the key to the attenuation of the oxidative stress-induced mitochondrial damage, which may be achieved by increasing the expression of the E3 ubiquitin ligase, Smad-ubiquitination regulatory factor 2 (Smurf2); thereby increasing the ubiquitination and degradation levels of TRPM2. CONCLUSION: Our results suggest that AZ is an effective candidate drug for ameliorating VaD and provide new insights into the current clinical treatment of VaD.

Kinetic and thermodynamic analysis of alizarin Red S biosorption by Alhagi maurorum: a sustainable approach for water treatment.

Synthetic dyes, such as Alizarin Red S, contribute significantly to environmental pollution. This study investigates the biosorption potential of Alhagi maurorum biosorbent for the removal of Alizarin Red S (ARS) from aqueous solutions. Fourier transform infrared spectroscopy (FTIR) was used to analyze the biosorbent's adsorption sites. Various parameters were optimized to maximize dye adsorption. An optimal removal efficiency of 82.26% was attained by employing 0.9 g of biosorbent with a 25 ppm dye concentration at pH 6 and 60 °C over 30 min. The data were modeled using various isothermal and kinetic models to understand the adsorption behavior. Thermodynamic parameters indicated that the adsorption process was spontaneous and endothermic. The pseudo-second-order kinetic model best described the data, indicating chemisorption as the rate-limiting step. The data matched best to the Langmuir model, indicating that the adsorption occurs as a monolayer on uniform surfaces with a finite number of binding sites. The model showed a strong correlation (R² = 0.991) and a maximum adsorption capacity (qmax) of 8.203 mg/g. Principal component analysis (PCA) identified temperature as the dominant factor, with the primary component, PC1 capturing 100% of its effect. The mechanisms involved in ARS biosorption on A. maurorum include electrostatic interactions, hydrogen bonding, hydrophobic interactions, dipole-dipole interactions, and π-π stacking. Alhagi maurorum showed promising potential for biosorbing toxic dyes from contaminated water, suggesting further investigation for practical applications.

Kinetics and thermodynamics investigations of efficient and eco-friendly removal of alizarin red S from water via acid-activated Dalbergia sissoo leaf powder and its magnetic iron oxide nanocomposite.

The present work aimed to highlight an efficient, readily accessible, and cost-effective adsorbent derived from Dalbergia sissoo (DS) leaf powder for removing the environmentally hazardous dye "alizarin red S" (ARS) from hydrous medium. A variant of the adsorbent is activated via sulfuric acid and composited with magnetic iron oxide nanoparticles (DSMNC). Both adsorbents are thoroughly characterized using techniques such as Fourier transform infrared spectroscopy, point of zero charge, energy-dispersive X-ray spectroscopy, and scanning electron microscopy, which show that they have a porous structure rich in active sites. Different adsorption conditions are optimized with the maximum removal efficiency of 76.63% for DS and 97.89% for DSMNC. The study was highlighted via the application of various adsorption isotherms, including Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich, to adsorption data. Pseudo-first-order, pseudo-second-order, and intra-particle diffusion models were utilized to investigate the kinetics and mechanism of adsorption. The Freundlich model and pseudo-second-order kinetics exhibited the best fit, suggesting a combination of physical interactions, as confirmed by the D-R and Temkin models. The dominant adsorbate-adsorbent interactive interactions responsible for ARS removal were hydrogen bonding, dispersion forces, and noncovalent aromatic ring adsorbent pi-interactions. Thermodynamic parameters extracted from adsorption data indicated that the removal of the mutagenic dye "ARS" was exothermic and spontaneous on both DS and DSMNC, with DSMNC exhibiting higher removal efficiency.

Comparative evaluation of the osteogenic capacity of second-generation platelet concentrates on dental pulp stem cells - An ex vivo study.

Introduction: Clinical evidence of platelet-rich fibrin (PRF) benefits on bone repair is still emerging, prompting researchers to experiment with different PRF formulations as osteoconductive scaffolds. Aims: This study compared the osteoconductive effects of injectable PRF (i-PRF) and leukocyte-rich PRF (L-PRF) on the differentiation of dental pulp stem cells (DPSCs) into osteoblasts. Materials and Methods: Blood samples were collected from the volunteers to prepare L-PRF and i-PRF conditioned media (CM) by centrifugation. DPSCs were isolated from impacted third molars and cultured. Proliferation of DPSCs in response to L-PRF and i-PRF was assessed by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Osteoinductive potential was evaluated through alkaline phosphatase (ALP) activity, alizarin red S (ARS) staining, growth factor levels (vascular endothelial growth factor [VEGF], transforming growth factor [TGF-beta]), and cytokine expression (interleukin 6 [IL-6], IL-8) after 7 days. Results: MTT assay results showed that both L-PRF and i-PRF increased DPSC proliferation relative to the control group. After 7 days in L-PRF and i-PRF CM, DPSCs exhibited increased ALP activity, higher red-colored calcium deposits with ARS staining, and elevated levels of VEGF and TGF-beta. In addition, higher concentrations of inflammatory cytokines IL-6 and IL-8 were observed in both L-PRF and i-PRF compared to the control. Conclusions: Using both L-PRF and i-PRF as scaffolds can enhance the osteoinductive ability of stem cells, offering a potential strategy for regenerative therapies.

Revealing Energy Density in Porous Carbon Supercapacitors Using Hydroquinone Sulfonic Acid as Cathodic and Alizarin Red S as Anodic Redox Electrolytes.

Exploration of innovative strategies aiming to boost energy densities of supercapacitors without sacrificing the power density and long-term stability is of great importance. Herein, highly porous nitrogen-doped carbon spheres (NPCS) are decorated onto the graphite sheets (GSs) through a hydrothermal route, followed by a chemical activation. The capacitive performance of the NPCS is then enhanced by hydroquinone sulfonic acid (HSQA) incorporation in both cathodic electrolyte and electrode materials. Later, NPCS are decorated with polypyrrole (PPY), in which HSQA takes a versatile role as conjugated polymer dopant and cathodic redox additive. The capacitive performance of the negative electrodes is enhanced by incorporating of alizarin red S (ARS) as anodic redox additive. Finally, PPY(HQSA)@NPCS-GS//NPCS-GS asymmetric supercapacitor is assembled and tested in dual redox electrolyte system containing HQSA-cathodic and ARS-anodic electrolytes. This device delivers a remarkable energy density of 60.37 Wh kg-1, which is close or even better than lead acid batteries. Thus, the present work provides a novel pathway to develop high energy supercapacitors using redox active electrolytes for next-generation energy storage applications.

Shining light on environmental remediation: a type-II heterojunction MnFe2O4/rGO nanocomposites for enhanced photocatalytic degradation of organic dyes and bisphenol A.

In this study, the pressing issue of persistent organic pollutants in wastewater was addressed by designing and fabricating a magnetically separable MnFe2O4/rGO heterostructure catalyst for efficient mineralization of bisphenol A (BPA) and dyes such as alizarin red S (anionic) and malachite green (cationic), which are known for their resistance to biodegradation and carcinogenic properties. Comprehensive structural and surface analyses using XRD, XPS, SEM, and TEM/HRTEM coupled with magnetic and optical property measurements revealed the formation of the MnFe2O4/rGO heterostructures. Among all, the MnFe2O4/rGO-10 catalyst with 10% wt% of rGO exhibited 100% efficiency in the mineralization of BPA and both dyes under visible light illumination within 60 min. The stability and recyclability of the catalyst, assessed through XRD and VSM studies, demonstrated its consistent performance over multiple uses. The cost-effectiveness and stability of this catalyst underscore its potential for practical application in wastewater treatment, offering a viable solution to the persistent challenge of removing stubborn organic contaminants.

Disposable electrochemical sensors based on reduced graphene oxide/polyaniline/poly(alizarin red S)-modified integrated carbon electrodes for the detection of ciprofloxacin in milk.

An electrochemical sensor based on an electroactive nanocomposite was designed for the first time consisting of electrochemically reduced graphene oxide (ERGO), polyaniline (PANI), and poly(alizarin red S) (PARS) for ciprofloxacin (CIPF) detection. The ERGO/PANI/PARS-modified screen-printed carbon electrode (SPCE) was constructed through a three-step electrochemical protocol and characterized using FTIR, UV-visible spectroscopy, FESEM, CV, LSV, and EIS. The new electrochemical CIPF sensor demonstrated a low detection limit of 0.0021 µM, a broad linear range of 0.01 to 69.8 µM, a high sensitivity of 5.09 µA/µM/cm2, and reasonable selectivity and reproducibility. Moreover, the ERGO/PANI/PARS/SPCE was successfully utilized to determine CIPF in milk with good recoveries and relative standard deviation (< 5%), which were close to those with HPLC analysis.

Ultrasonic-driven chemical reduction synthesis of alizarin complexone-modified gold nanoparticles for dual-signal colorimetric and fluorometric sensing of histamine in seafood products.

Alizarin complexone-modified gold nanoparticles (Au0-NPsALz) were synthesized using a proposed ultrasonic irradiation-assisted chemical reduction method. Ultrasonic irradiation powers, reaction time and alizarin complexone concentration had been proven to be the main parameters for controlling the nucleation and growth of Au0-NPsALz. In the synthesized ultrasonic irradiation-assisted chemical reduction conditions, Au0-NPsALz had a spherical oriented morphology with a uniform size of 17.84 ± 1.37 nm and are shiny red with a surface plasmon resonance (SPR) of 535 nm. A rapid colorimetric and fluorometric dual-mode detection strategy for selective detection of histamine in seafood was developed based on the self-assembly of Au0-NPsALz-Ni (II) complexes. Ni (II) can capture the histamine molecules close to Au0-NPsALz surfaces, making changes in the colorimetric and fluorometric responses of the solution. The quantitative analysis of histamine was realized through the variation of dual-signal colorimetric and fluorometric responses. Such Au0-NPsALz sensor offered good detection sensitivity for histamine with a detection limit (LOD) of 59.32 µmol L-1 and 116.20 µmol L-1 and wide linear response within the range of 10-10000 µmol L-1 (R2 = 0.9952) and 100-5000 µmol L-1 (R2 = 0.9947) for colorimetric and fluorometric measurement, respectively. Recoveries ranging from 94.99 to 103.29 % and 97.67-106.88 % for colorimetric and fluorometric assay were obtained, showing low levels of matrix effects. Particularly, the results of the dual-mode sensor were also validated by comparing with the HPLC method for improving the assay accuracy and dependability. Ultimately, the developed Au0-NPsALz colorimetric and fluorometric probe performs excellently in practical applications, with promising results for detecting histamine in seafood products.

The Use of Novel Colorimetric Films to Monitor the Freshness of Pork, Utilizing Konjac Glucomannan With Curcumin/Alizarin.

In this study, different proportions of curcumin (CUR) and alizarin (ALI) were added to konjac glucomannan (KG)/ polyvinyl alcohol (PVA) to prepare an active intelligent packaging film and evaluate its potential to indicate pork freshness. The mixed indicator had a richer color hierarchy in the buffer solution with pH = 2-12. The surface of the KG-2C2A and KG-1C3A films is smoother and has fewer cross-section faults. With the increase of CUR content in the film, the crystal structure becomes more prominent, leading to poor compatibility with KG. The WAC of KG-3C1A and KG-1C3A films was significantly higher than that of the other groups, and they had better hydrophobicity. With the increase of CUR content in the films, the thermal stability of the films was enhanced, and the KG-C films showed the highest thermal stability. Among them, the KG-2A2C and KG-1C3A films showed the most significant color change during pork spoiling and could be used to monitor the freshness of pork. As a pH colorimetric indicator, CUR and ALI-coated KG films might be of great potential in fresh meat monitoring.

Canine corneal endothelial cell analysis using vital dyes and light microscopy.

PURPOSE: To evaluate the use of vital dyes and light microscopy for assessing canine corneal endothelial morphology ex vivo. METHODS: The corneas of 40 canine eyes (n = 20 dogs) enucleated <24 h following euthanasia or death were isolated and flat-mounted on a slide. Corneal endothelium was stained via 0.25% trypan blue followed by 0.5% alizarin red (pH 4.2), photographed, then the following morphological features were calculated using ImageJ: mean cell density (MCD), mean cell area (MCA), polymegathism (coefficient of variation of cell area), and pleomorphism (% hexagonality). RESULTS: Mean ± standard deviation (range) outcomes were: MCD, 2544 ± 541 cells/mm2 (1750-3922 cells/mm2); MCA, 431 ± 97 µm2 (251-626 µm2); polymegathism, 17 ± 2% (14%-22%); pleomorphism, 84 ± 3% (80%-90%). No significant differences (p ≥ .122) were noted for any outcome between male versus female or brachycephalic versus non-brachycephalic dogs. Young dogs (<10 years) had lower MCA (p = .044), lower pleomorphism (p = .003), and higher MCD (p = .035) when compared to older dogs (≥10 years). Age was significantly (p ≤ .049) correlated with MCA (r = 0.467), MCD (r = -0.476), polymegathism (r = 0.444), and pleomorphism (r = 0.609). CONCLUSIONS: The combination of vital dyes and light microscopy allowed for clear visualization and evaluation of the corneal endothelium in canine eyes ex vivo. Our findings can be used in future studies to deepen our understanding of the corneal endothelium in health and disease.

Sodium alginate/chitosan-based intelligent multifunctional bilayer film for shrimp freshness retention and monitoring.

Developing bifunctional innovative food packaging for maintaining and monitoring food freshness is crucial for food safety. Here, we prepared tannic acid cinnamaldehyde nanoemulsions through self-assembly and ionic cross-linking between the natural emulsifiers tannic acid and cinnamaldehyde, and were incorporated into chitosan as a protective outer layer. Sodium alginate anchored with alizarin was employed as the sensing inner layer. A pH-sensitive bilayer film integrating real-time monitoring and maintenance of food fresh food freshness was designed using layer-by-layer assembly (LBL) technology. The prepared bilayer film exhibited 100 % UV protection, >99 % antimicrobial effect, and 94.86 % and 97.91 % clearance rates for DPPH and ABTS free radicals, respectively. In addition, the bilayer film exhibited high biosafety and sensitive, reversible, and rapid response to pH/NH3. Shrimp preservation experiments showed that the smart bilayer film could effectively slow down the growth of microorganisms on the surface of shrimp, extend the freshness period of shrimp, and could monitor the freshness of shrimp in real-time through color changes. In conclusion, the prepared SL-CCT bilayer film has excellent potential for food preservation and freshness monitoring, providing a new perspective for design and development of multifunctional smart food packaging films.

Molecularly imprinted Ag2S quantum dots with high photocatalytic activity for dye removal: Experimental and DFT insights.

Molecular imprinted polymers (MIPs) were developed by carrying out the cocktail solution of Template ((Salata, 2004)-Gingerol), monomer, crosslinker, and Ag2S Quantum Dots (QDs) by ex-situ dissolved in an appropriate solvent, resulting in an efficient crosslinked polymer composite. Degradation of Alizarin red S (ARS) dye and yellowish sunset (SY) azo dye under visible light irradiation was reported first time by the introduction of prepared MIPs composite. In this research, the result shows efficient photocatalyt activity of Ag2S-MIPs composite for the degradation of AR and SY dye with degradation% (80%) and (84%) in the aqueous wastewater. The degradation efficiency of the Ag2S-MIPs composite and the Ag2S QD associated with non-imprinted polymers (NIPs) (i.e.Ag2S-NIPs composite) were calculated by using different parameters such as catalyst dose, pH value, optimum time and concentration variation and the observations are evocative. Moreover, the density functional theory (DFT) approach was also used to analyze the structural, stability/energetics, and electronic features of the organic-inorganic hybrid composites of the Ag2S QD with the MIPs based on (Salata, 2004)-gingerol extract. The proposed QD and MIPs (EGDMA and (Salata, 2004)-Gingerol) composite model has been detected to be the most stable because it shows the largest binding energy (BE) among the three chosen composite models. It was found out that imprinted polymers were superior in enhancing the degradation of dyes when compared to non imprinted polymers. Introducing MIPs into the valence band accelerates the catalysis properties to stabilize newly fashioned excitons that are basically generated as a result of light excitation in presence of Ag2S Quantum Dots (QDs) and molecular imprinted polymer (MIPs). Motivation behind this work is to address the challenges related to environmental pollution causing by organic dyes. These toxins are known to cause diverse symptoms (e.g., skin irritation, eye infection, respiratory disorders, and even cancer) once exposed through ingestion and inhalation. Through incorporation of Ag2S QD into MIP,the purpose of this research is to enhance the selectivity, specificity and photocatalytic activity for dyes and that work holds a potential towards environmental remediation by developing a cost effective and sustainable method for controlling pollution in water.

The antihypertensive effect of Alizarin is achieved by activating VEGFR2/eNOS pathway, attenuating oxidative stress-induced mitochondrial damage and premature senescence.

The primary and initial manifestations of hypertension encompass arterial hypoelasticity and histiocyte senescence. Oxidative stress plays a pivotal role in the progression of senescence. Elevated intracellular oxidative stress levels will directly induce cell damage, disrupt normal physiological signal transduction, which can cause mitochondrial dysfunction to accelerate the process of senescence. Alizarin, an anthraquinone active ingredient isolated from Rubia cordifolia L., has a variety of pharmacological effects, including antioxidant, anti-inflammatory and anti-platelet. Nevertheless, its potential in lowering blood pressure (BP) and mitigating hypertension-induced vascular senescence remains uncertain. In this study, we used spontaneously hypertensive rats (SHR) and human umbilical vein endothelial cells (HUVECs) to establish a model of vascular senescence in hypertension. Our aim was to elucidate the mechanisms underpinning the vascular protective effects of Alizarin. By assessing systolic blood pressure (SBP) and diastolic blood pressure (DBP), H&E staining, SA-ß-Gal staining, vascular function, oxidative stress levels, calcium ion concentration and mitochondrial membrane potential, we found that Alizarin not only restored SBP and increased endothelium-dependent relaxation (EDR) in SHR, but also inhibited oxidative stress-induced mitochondrial damage and significantly delayed the vascular senescence effect in hypertension, and the mechanism may be related to the activation of VEGFR2/eNOS signaling pathway.

A facile synthesis of water-soluble copper nanoclusters as label-free fluorescent probes for rapid, selective and sensitive determination of alizarin red.

Copper nanoclusters (FA@CuNCs) emitting blue fluorescence were successfully developed via a one-pot technique. In this method, the copper chloride, folic acid and hydrazine hydrate were applied as a precursor, protective agent and reducing agent, respectively. The absorption, fluorescence excitation and emission spectra of FA@CuNCs were carried out by using ultraviolet-visible and fluorescence spectrometry, respectively. The morphology, particle size, functional groups, oxidation states of elements of FA@CuNCs were discussed via using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The stability of FA@CuNCs was studied under various conditions, such as storage time at 25 ℃, ultraviolet radiation time, sodium chloride solutione and pH. The FA@CuNCs displayed blue fluorescence under the excitation wavelength of 361 nm, and the fluorescence quantum yield was 7.45 %. As a result of the inner filter effect, the alizarin red could significantly weaken the blue fluorescence of FA@CuNCs. Thus, the as-prepared FA@CuNCs could be utilized as fluorescence nanosensors for the trace determination of alizarin red. This platform suggested an excellent linear range for alizarin red varying from 0.5 to 200 µM with a fitting coefficient of 0.9955. The detection limit was calculated to be 0.064 µM in the light of the 3b/k (b and k refer to the standard deviation and slope of fitted curve, respectively). Furthermore, the as-developed FA@CuNCs could be used to detect the alizarin red in real samples and for the sensing of temperature.

Ammonia-Responsive Colorimetric Film of Phytochemical Formulation (Alizarin) Grafted onto ZIF-8 Carrier with Poly(vinyl alcohol) and Sodium Alginate for Beef Freshness Monitoring.

In this study, we devised a photothermally stable phytochemical dye by leveraging alizarin in conjunction with the metal-organic framework ZIF-8 (AL@ZIF-8). The approach involved grafting alizarin into the microporous structure of ZIF-8 through physical adsorption and hydrogen-bonding interactions. AL@ZIF-8 significantly enhanced the photostability and thermostability of alizarin. The nanoparticles demonstrate substantial color changes in various pH environments, showcasing their potential for meat freshness monitoring. Furthermore, we introduced an intelligent film utilizing poly(vinyl alcohol)-sodium alginate-AL@ZIF-8 (PA-SA-ZA) for detecting beef freshness. The sensor exhibited a superior water contact angle (52.34°) compared to the alizarin indicator. The color stability of the film was significantly enhanced under visible and UV light (ΔE < 5). During beef storage, the film displayed significant color fluctuations correlating with TVB-N (R2=0.9067), providing precise early warning signals for assessing beef freshness.

Vanadium and strontium co-doped hydroxyapatite enriched polycaprolactone matrices for effective bone tissue engineering: A synergistic approach.

Scientific research targeted at enhancing scaffold qualities has increased significantly during the last few decades. This emphasis frequently centres on adding different functions to scaffolds in order to increase their usefulness as instruments in the field of regenerative medicine. This study aims to investigate the efficacy of a multifunctional sustainable polymer scaffold, specifically Polycaprolactone (PCL) embedded with hydroxyapatite co-doped with vanadium and strontium (HVS), for bone tissue engineering applications. Polycaprolactone was used to fabricate the scaffold, while hydroxyapatite co-doped with vanadium and strontium (HVS) served as the nanofiller. A thorough investigation of the physicochemical and biological characteristics of the HVS nanofiller was carried out using cutting-edge techniques including Dynamic Light Scattering (DLS), and X-ray Photoelectron Spectroscopy (XPS) and in vitro cell studies. A cell viability rate of more than 70 % demonstrated that the synthesised nanofiller was cytotoxic, but in an acceptable range. The mechanical, biological, and physicochemical properties of the scaffold were extensively evaluated after the nanofiller was integrated. The water absorption characteristics of scaffold were enhanced by the addition of HVS nanofillers, leading to increased swelling, porosity, and hydrophilicity. These improvements speed up the flow of nutrients and the infiltration of cells into the scaffold. The scaffold has been shown to have important properties that stimulate bone cell activity, including better biodegradability and improved mechanical strength, which increased from 5.30 ± 0.37 to 10.58 ± 0.42 MPa. Further, its considerable antimicrobial qualities, blood-compatible nature, and capacity to promote biomineralization strengthen its appropriateness for usage in biomedical applications. Mainly, enhanced Alkaline phosphatase (ALP) activity, Alizarin Red Staining (ARS) activity, and excellent cell adhesive properties, indicating the outstanding osteogenic potential observed in rat bone marrow-derived stromal cells (rBMSC). These combined attributes highlight the pivotal role of these nanocomposite scaffolds in the field of bone tissue engineering.

A sensitive and selective voltammetric method for the detection of pyrogallol in tomato and water samples using platinum electrode modified with alizarin red S film.

In contrast to the hyperactive platinum electrode, ARS modified platinum electrode presents a remarkable inertness toward adsorption and surface processes and lends it for further voltammetric applications. Measuring pyrogallol levels in samples is significant for assessing their antioxidant activity, which is crucial for understanding their potential health benefits and ability to combat oxidative stress. In addition, the excess consumption of pyrogallol can have significant negative effects on human health. A voltammetric sensor has been developed for the determination of pyrogallol using ARS modified platinum electrode. The electrode was prepared by electrodeposition of alizarin red S on a platinum electrode using cyclic voltammetry with a potential scan range of - 0.4 to 1.2 V against an Ag/AgCl quasi reference electrode for 60 cycles as optimum number of cycles. The modified electrode was characterized by CV and SEM techniques. This modified alizarin red S platinum electrode showed remarkable electrocatalytic performance and stability, resulting in a significant increase in pyrogallol oxidation current by 11.05% compared to the pyrogallol oxidative current at the unmodified platinum electrode. A well-defined oxidation peak was observed at ~ 0.40 V. The sensor exhibited a low limit of detection (LOD) of 0.28 µM and a linear standard curve covering the ranges of 1.0-40 µM and 0.01-10.0 mM pyrogallol. Extensive studies were performed to evaluate possible interferences from various organic and inorganic compounds and yielded satisfactory results that confirm the selectivity of the developed sensor for pyrogallol determination. In addition, the ARS-Pt electrode provided consistently reliable results for the accurate detection of pyrogallol in water and tomato samples.

A novel and efficient voltammetric sensor for the simultaneous determination of alizarin red S and tartrazine by using poly(leucine) functionalized carbon paste electrode.

In the current work, a rapid, selective, and sensitive technique was developed for the detection of Alizarin Red S (ARS) by applying poly leucine modified carbon paste electrode (PLMCPE). Electrochemical impedance spectroscopy (EIS) and Scanning electron microscopy (SEM) were utilized to study the surface morphology of unmodified carbon paste electrode (UMCPE) and PLMCPE. The active surface area for UMCPE and PLMCPE was found to be 0.0012 cm2 and 0.0026 cm2 respectively. The electrochemical response of ARS at UMCPE and PLMCPE was analyzed using cyclic voltammetry (CV) in the potential window of 0.4 to 1.0 V. The cyclic voltammogram obtained for varying the pH of 0.2 M phosphate buffer (PB) solution showed maximum current for the oxidation of ARS at pH 6.5. The electrochemical reaction of ARS was found to be irreversible and adsorption controlled. The effect of variation of concentration of ARS on the oxidation peak current was evaluated using CV and linear scan voltammetry (LSV). A linear relationship between the concentration variation and current was obtained in the linear range of 1.5 µM-3.5 µM and 0.2 µM-5.0 µM for CV and LSV respectively. The limit of detection (LOD) of 0.68 µM for the CV method and 0.29 µM for the LSV method was exhibited by the developed sensor. The simultaneous study of ARS along with tartrazine (TZ) showed good selectivity for ARS. The interferents of foreign molecules showed no effect on the selectivity of the electrode. The applicability of PLMCPE on real samples gave good recovery ranging from 97.46-101.2%; hence, the sensor can be utilized on real samples. The developed sensor has good stability and sensitivity.

A novel dual-channel cassava starch/polyvinyl alcohol-based film for visual monitoring of shrimp freshness.

In this study, the polyvinylpyrrolidone-alizarin nanoparticles (PVP-AZ NPs) with favorable water dispersion and the carbon quantum dots (RQDs) with aggregate induced emission effect were synthesized to construct an eco-friendly film for food freshness monitoring. The introduction of PVP-AZ NPs and RQDs enhanced the network structure and thermal stability of the cassava starch/polyvinyl alcohol film, and reduced its crystallinity and light transmittance via non-covalent binding with the film-forming matrix. The developed film exhibited visually recognizable colorimetric and fluorescent responses to ammonia at 0.025-25 mg/mL, and it can be reused at least 6 times. Practical application experiment proved that the film, as an indicator label, can achieve accurate, real-time, and visual dynamic monitoring of the freshness of shrimp stored at 25 °C, 4 °C, and - 20 °C under daylight (orange yellow to purple) and UV light (red to blue). The integration of multivariate detection technology can eliminate the interference of external factors by self-correction to improve sensitivity and reliability, which provides a reference for the development of other food quality and safety monitoring platforms.