Diffusion in biological media: a comprehensive numerical-analytical study via surface analysis and diffusivities calculation.

The study of diffusion in biological materials is crucial for fields like food science, engineering, and pharmaceuticals. Research that combines numerical and analytical methods is needed to better understand diffusive phenomena across various dimensions and under variable boundary conditions within food matrices. This study aims to bridge this gap by examining the diffusion of substances through biological materials analytically and numerically, calculating diffusivity and conducting surface analysis. The research proposes a process for sweetening Bing-type cherries (Prunus avium) using sucrose/xylitol solutions and a staining technique utilising erythrosine and red gardenia at varying concentrations (119, 238 and 357 ppm) and temperatures (40, 50 and 60 °C). Given the fruit's epidermis resistance, the effective diffusivities of skin were inferior to those in flesh. Temperature and concentration synergise in enhancing diffusion coefficients and dye penetration within the food matrix (357 ppm and 60 °C). Red gardenia displayed significant temperature-dependent variation (p = 0.001), whereas erythrosine dye remained stable by temperature changes (p > 0.05). Gardenia's effective diffusivities in cherry flesh and skin, at 357 ppm and 60 °C, 3.89E-08 and 6.61E-09 m2/s, respectively, significantly differed from those obtained at lower temperatures and concentrations. The results highlight the temperature-concentration impacts on mass transfer calculations for food colouring processes and preservation methodologies.

A green, fluorescent probe employing erythrosine-B for tracing the accidental administration of levamisole in milk and plasma samples.

A simple and sensitive fluorescent probe has been developed and optimized to detect the non-intentional administration of levamisole (LVM). LVM is used as an anthelmintic therapy in cows, and hence, its residues appear in the drained milk until 60 hours after administering the drug. Meanwhile, levamisole is known to be an adulterant to cocaine and could be detected in addicts' plasma samples. Owing to its severe side effects, including agranulocytosis, which is lethal in many cases, detection and quantification of LVM in milk and plasma samples are of utmost importance. Therefore, a sensitive and selective analytical method is required for this purpose. This work develops a highly fluorescent probe obtained through the reaction between LVM and erythrosine-B in an acidic medium, where the produced ion pair complex has been measured at 553 nm after excitation at 528 nm. The proposed method provides linearity over the concentration range of 0.5-2.0 µg mL-1 for LVM, with a corresponding detection and quantitation limit of 0.5 and 0.3 µg mL-1. Full validation was performed, permitting the application of the suggested method to perform simple extraction steps. All the applied procedures followed the guidelines offered by green analytical chemistry, where the Green Analytical Procedure Index (GAPI) assessed the greenness of the proposed tool, and the yielded pictograms proved the eco-friendliness of the offered tool.

Utility of native emission quenching of erythrosine B for the determination of diltiazem in different dosage forms.

This study introduces a practical and cost-effective method for tracking diltiazem (DLZ) analytically. It utilizes a fluorimetric approach that relies on the modulation of fluorescence intensity of a dye called erythrosine B. Through a one-pot experiment performed in an acidic environment, a complex is rapidly formed between DLZ and erythrosine B. By observing the decrease in erythrosine B emission, a linear calibration plot is established, enabling the detection and quantification of DLZ concentrations ranging from 40 to 850 ng/ml. The estimated limits of detection and quantitation were 10.5 and 32.1 ng/ml, respectively. The variables affecting the DLZ-dye complex system were carefully adjusted. The validity of the approach was confirmed through a thorough evaluation based on the criteria set by ICH guidelines. The accuracy and precision of the methodology were evaluated, and the standard deviation and relative standard deviation were below 2. The strategy was successfully employed to analyze DLZ in tablets and capsules, and no significant variation between the proposed and reported methods as the values of the estimated t-test and F-test at five determinations were below 2.306 and 6.338, respectively. Notably, the method adheres to the principle of green chemistry by utilizing distilled water as the dispersing medium.

Design of resonance Rayleigh scattering and spectrofluorimetric methods for the determination of the antihistaminic drug, hydroxyzine, based on its interaction with 2,4,5,7-tetraiodofluorescein: Evaluation of analytical eco-scale and greenness/whiteness algorithms.

In this work, two validated approaches were used for estimating hydroxyzine HCl for the first time using resonance Rayleigh scattering (RRS) and spectrofluorimetric techniques. The suggested approaches relied on forming an association complex between hydroxyzine HCl and 2,4,5,7-tetraiodofluorescein (erythrosin B) reagent in an acidic media. The quenching in the fluorescence intensity of 2,4,5,7-tetraiodofluorescein by hydroxyzine at 551.5 nm (excitation = 527.5 nm) was used for determining the studied drug by the spectrofluorimetric technique. The RRS approach is based on amplifying the RRS spectrum at 348 nm upon the interaction of hydroxyzine HCl with 2,4,5,7-tetraiodofluorescein. The spectrofluorimetric methodology and the RRS methodology produced linear results within ranges of 0.15-1.5 µg ml-1 and 0.1-1.2 µg ml-1, respectively. LOD values for these methods were determined to be 0.047 µg ml-1 and 0.033 µg ml-1, respectively. The content of hydroxyzine HCl in its pharmaceutical tablet was estimated using the developed procedures with acceptable recoveries. Additionally, the application of four greenness and whiteness algorithms shows that they are superior to the previously reported method in terms of sustainability, economics, analytical performance, and practicality.

Study on the interaction between erythrosine B and the cardiac drug amiodarone using fluorescence, scattering, and absorbance spectra and their analytical application.

In an acidic buffered solution, erythrosine B can react with amiodarone to form an association complex, which not only generates great enhancement in resonance Rayleigh scattering (RRS) spectrum of erythrosine B at 346.5 nm but also results in quenching of fluorescence spectra of erythrosine B at λemission = 550.4 nm/λexcitation = 528.5 nm. In addition, the formed erythrosine B-amiodarone complex produces a new absorbance peak at 555 nm. The spectral characteristics of the RRS, absorbance, and fluorescence spectra, as well as the optimum analytical conditions, were studied and investigated. As a result, new spectroscopic methods were developed to determine amiodarone by utilizing erythrosine B as a probe. Moreover, the ICH guidelines were used to validate the developed RRS, photometric, and fluorimetric methods. The enhancements in the absorbance and the RRS intensity and the decrease in the fluorescence intensity of the used probe were proportional to the concentration of amiodarone in ranges of 2.5-20.0, 0.2-2.5, and 0.25-1.75 µg/mL, respectively. Furthermore, limit of detection values were 0.52 ng/mL for the spectrophotometric method, 0.051 µg/mL for the RRS method, and 0.075 µg/mL for the fluorimetric method. Moreover, with good recoveries, the developed spectroscopic procedures were applied to analyze amiodarone in its commercial tablets.

Efflux Pump Inhibitor Potentiates the Antimicrobial Photodynamic Inactivation of Multidrug-Resistant Acinetobacter baumannii.

Background: Acinetobacter baumannii, a nosocomial pathogen, poses a major public health problem due to generating resistance to several antimicrobial agents. Antimicrobial photodynamic inactivation (APDI) employs a nontoxic dye as a photosensitizer (PS) and light to produce reactive oxygen species that destroy bacterial cells. The intracellular concentration of PS could be affected by factors such as the function of efflux pumps to emit PS from the cytosol. Objective: To evaluate the augmentation effect of an efflux pump inhibitor, verapamil, three multidrug-resistant A. baumannii were subjected to APDI by erythrosine B (EB). Methods and results: The combination of EB and verapamil along with irradiation at 530 nm induced a lethal effect and more than 3 log colony-forming unit reduction to all A. baumannii strains in planktonic state. In contrast, EB and irradiation alone could produce only a sublethal effect on two of the strains. Conclusions: These data suggest that verapamil increases the intracellular concentration of EB, which potentiates the lethal efficacy of APDI. Verapamil could be applied with EB and green light to improve their antimicrobial efficacy against A. baumannii-localized infections.

Green spectrophotometric and spectrofluorimetric determination of biperiden hydrochloride using erythrosine B sensing probe.

Erythrosine B (EB) is a food colorant antiviral xanthene dye that has many applications as a color additive in pharmaceuticals and cosmetics. Its use as a sensor for spectrofluorimetric and spectrophotometric analysis of amine-based pharmaceuticals renders many advantages because of its availability, low cost, rapid labeling, and high sensitivity. Herein, two fast and sensitive spectrofluorimetric and spectrophotometric methods were established for the estimation of the anti-Parkinson drug, biperiden (BIP) hydrochloride (HCl), in its raw material and tablet forms. The proposed methods depended on the interaction between the phenolic group of EB and the tertiary amino group of the studied analyte to form an ion-pair complex at pH 4 using the Britton Robinson buffer. The spectrofluorimetric method is based on the measurement of the quenching power of BIP HCl on the fluorescence intensity of EB at λex/em = 527.0/550.9 nm. This method was rectilinear over the concentration range of 0.1-1.0 µg/mL with a limit of detection (LOD) = 0.017 µg/mL and a limit of quantification (LOQ) = 0.05 µg/mL. Meanwhile, the colorimetric method involved monitoring the absorbance of the formed ion-pair complex at 555 nm, showing a linearity range of 0.4-5.0 µg/mL with LOD = 0.106 µg/mL and LOQ = 0.322 µg/mL. The proposed methods were assessed for the greenness, indicating the greenness of the developed methods.

Integration of a facile sustainable resonance Rayleigh scattering switchable-based system for feasible determination of centrophenoxine, a nootropic and antioxidant agent; application to crude materials and dosage forms.

The proposed research adheres to a certain methodology to ensure that the technique used for analyzing the centrophenoxine drug is sustainable and green. It is important to highlight that several tools that have been recently developed were utilized as potential indicators of environmental sustainability and applicability. The present research presents a novel and entirely innovative method utilizing ultrasensitive spectrofluorimetry for the detection of centrophenoxine (CPX) drug. The employed methodology in this study involved the utilization of one-step, one-pot, and direct spectrofluorimetric technique, which was found to be both efficient and environmentally sustainable in the validation and assessment of the drug. Simply, when CPX and erythrosine B reagent were combined in an acidic environment, the highly resonance Rayleigh scattering product was immediately produced. The sensitivity limits were observed to be within the range of 15-47 ng mL-1, whereas the linearity was assessed to be in the range of 50-2000 ng mL-1. The optimal settings for all modifiable parameters of the system were ascertained through an analysis of centrophenoxine-erythrosine B complexes. Moreover, the system demonstrated compliance with International Council for Harmonization (ICH) specifications without encountering any issues. The suggested process was then rated on different recent environmental safety measuring metrics to see how good it was for the environment. Fortunately, the WAC standards that combine ecological and functional elements utilizing the Green/Red/Blue (RGB 12) design also acclaimed the current analytical technique as a white one. Additionally, a new applicability evaluation tool (BAGI) was employed to estimate the practicability of the planned method in the analytical chemistry field.

Optimization of the Erythrosine-mediated photodynamic therapy against Escherichia coli using response surface methodology.

BACKGROUND: The efficacy of photodynamic therapy (PDT) depends on the combination of light and a photosensitizer for inactivation of microorganisms. However, finding the ideal conditions for the factors involved in this technique is time and cost-consuming. The rotational composite central design (RCCD) is a tool that can be allied with PDT to achieve precise results within a shorter working time. METHODS: This study used the response surface methodology to optimize the parameters of PDT mediated by Erythrosine (ERY) and green light-emitting diodes (LED) in different Escherichia coli strains by applying RCCD. RESULTS: The RCCD predicted optimum values of ERY and light exposure on PDT. According to the experimental results, the light exposure time showed the most significant influence on the inactivation of the evaluated bacteria. The optimized operating conditions were validated in laboratory tests, and no viable cells were recovered with ERY at 116 µmol L-1 and 30 min of light (33.34 J cm2) for E. coli ATCC 25922, 108 µmol L-1 and 40 min (44.38 J cm2) for E. coli ATCC 35218, and 108 µmol L-1 and 29.3 min (32.5 J cm2) for E. coli O157:H7 EDL 933. CONCLUSION: The adjusted polynomial models provided accurate information on the combined effects of ERY and lighting time with green LED on PDT. The application of the RCCD, in addition to reducing the number of experiments, also allows for increased quantity and quality of the results. Therefore, surface response methodology combined with PDT is a promising approach to inactivate E. coli.

Novel rod-like [Cu(phen)2(OAc)]·PF6 complex for high-performance visible-light-driven photocatalytic degradation of hazardous organic dyes: DFT approach, Hirshfeld and fingerprint plot analysis.

A novel octahedral distorted coordination complex was formed from a copper transition metal with a bidentate ligand (1,10-Phenanthroline) and characterized by Ultraviolet-visible spectroscopy, Ultraviolet-visible diffuse reflectance spectroscopy, Fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller, Field emission scanning electron microscopy, and Single-crystal X-ray diffraction. The Hirshfeld surface and fingerprint plot analyses were conducted to determine the interactions between atoms in the Cu(II) complex. DFT calculations showed that the central copper ion and its coordinated atoms have an octahedral geometry. The Molecular electrostatic potential (MEP) map indicated that the copper (II) complex is an electrophilic compound that can interact with negatively charged macromolecules. The HOMO-LUMO analysis demonstrated the π nature charge transfer from acetate to phenanthroline. The band gap of [Cu(phen)2(OAc)]·PF6 photocatalyst was estimated to be 2.88 eV, confirming that this complex is suitable for environmental remediation. The photocatalytic degradation of erythrosine, malachite green, methylene blue, and Eriochrome Black T as model organic pollutants using the prepared complex was investigated under visible light. The [Cu(phen)2(OAc)]·PF6 photocatalyst exhibited degradation 94.7, 90.1, 82.7, and 74.3 % of malachite green, methylene blue, erythrosine, and Eriochrome Black T, respectively, under visible illumination within 70 min. The results from the Langmuir-Hinshelwood kinetic analysis demonstrated that the Cu(II) complex has a higher efficiency for the degradation of cationic pollutants than the anionic ones. This was attributed to surface charge attraction between photocatalyst and cationic dyes promoting removal efficiency. The reusability test indicated that the photocatalyst could be utilized in seven consecutive photocatalytic degradation cycles with an insignificant decrease in efficiency.

Morphological changes and viability of Streptococcus mutans biofilm treated with erythrosine: A confocal laser scanning microscopy analysis.

Antimicrobial photodynamic therapy (a-PDT) is a modality that aims to induce microorganisms through visible light, a photosensitizer, and molecular oxygen. This therapy has shown promising results in controlling cariogenic biofilm in vitro and in vivo counterparts. This study investigated bacterial viability and morphological characterization of Streptococcus mutans mature biofilms after combination of erythrosine and a high potency dental curing light. Biofilms were formed on saliva-coated hydroxyapatite disks in batch culture. The samples were performed in triplicates. Fresh medium was replaced daily for five days and treated using 40 µM of E activated by HL 288 J/cm2 and total dose of 226 J at 1200 mW/cm2. Phosphate buffer saline and 0.12% of chlorhexidine were used as negative and positive control, respectively. After treatment, biofilms were assessed for microbial viability and morphological characterization by means of bio-volume and thickness. COMSTAT software was used for image analysis. Data were analyzed using two-way ANOVA followed by Tukey test with significance level 5%. The application of a-PDT and CHX treatments decreased S. mutans bacterial viability. The image analysis showed more red cells on biofilms when compared to other groups, demonstrating photobacterial killing. Erythrosine irradiated with a high potency curing light can potentially act as an antimicrobial tool in the treatment of cariogenic biofilms. The morphology and viability of microorganisms were impacted after treatment. Treatment with photodynamic therapy may be able to reduce the bio-volume and viability of bacteria present in biofilms. CLINICAL RELEVANCE AND RESEARCH HIGHLIGHTS: The use of the a-PDT technique has been applied in dentistry with satisfactory results. Some applications of this technique are in stomatology and endodontics. In the present study, we sought to understand the use of photodynamic therapy in the control of biofilm and the results found are compatible with the objective of microbiological control proposed by this technique, thus raising the alert for future studies in vivo using the combination of a-PDT with erythrosine, since they are easily accessible materials for the dental surgeon and can be applied in clinical practice.

Antimicrobial photodynamic therapy against Lactobacillus casei using curcumin, nano-curcumin, or erythrosine and a dental LED curing device.

This study aimed to investigate the photodynamic effects of curcumin, nanomicelle curcumin, and erythrosine on Lactobacillus casei (L. casei). Various concentrations of curcumin (1.5 g/L, 3 g/L), nano-curcumin (3 g/L), and erythrosine (100 µM/L, 250 µM/L) were tested either alone or combined with light irradiation (PDT effect) against L. casei in planktonic and biofilm cultures. The light was emitted from a light-emitting diode (LED) with a central wavelength of 450 nm. A 0.12% chlorhexidine digluconate (CHX) solution served as the positive control, and a solution containing neither photosensitizer nor light was the negative control group. The number of viable microorganisms was determined using serial dilution. There was a significant difference in the viability of L. casei in both planktonic and biofilm forms (P < 0.05). In the planktonic culture, the antibacterial effects of CHX and PDT groups with curcumin 3 g/L and erythrosine 250 µM/L were significantly greater than the other groups (P < 0.05). For L. casei biofilms, the greatest toxic effects were observed in CHX and PDT groups with curcumin 3 g/L, erythrosine 250 µmol/L, erythrosine 100 µmol/L, and nanomicelle curcumin 3 g/L, with a significant difference to other groups (P < 0.05). The antibacterial effects of all photosensitizers (except erythrosine 250 µmol/L at planktonic culture) enhanced significantly when combined with light irradiation (P < 0.05). PDT with curcumin 3 g/L or erythrosine 250 µmol/L produced comparable results to CHX against L. casei at both planktonic and biofilm cultures. Alternatively, PDT with erythrosine 100 µmol/L or nanomicelle curcumin 3 g/L could be suggested to kill L. casei biofilms.

Visible light-active samarium manganite nanostructures for enhanced water-soluble pollutant degradation.

In this study, a green approach was used to synthesize SmMnO3 magnetic nanoparticles via the auto combustion method, where pomegranate juice was utilized as a natural fuel. The concentration of fuel was varied to investigate its effect on the purity and morphology of SmMnO3 nanoparticles. The physiochemical properties of the synthesized nanoparticles, including crystal structures, morphology, optical, and magnetic properties, were investigated using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier-Transform Infrared Spectroscopy (FTIR), Vibrating Sample Magnetometer (VSM), Diffuse Reflectance Spectroscopy (DRS), X-ray fluorescence (XRF) and Brunauer-Emmett-Teller (BET). The band gap of the as-synthesized nanoparticles was determined to be 1.8 eV, indicating their potential as a photocatalyst. The photocatalytic activity of SmMnO3 nanoparticles was evaluated against Methyl violet and Erythrosine, and the mechanism of photocatalyst was determined using EDTA, benzoic acid, and benzoquinone as scavengers. Photocatalytic activity was studied in both UV and visible light, and it was found that the maximum degradation (94%) was related to the degradation of Erythrosine (10 ppm) in the presence of visible light. The stability test of SmMnO3 performed and confirmed the stability of nanoparticles after 5 cycles. The results suggest that SmMnO3 nanoparticles synthesized via the green auto combustion method using pomegranate juice as a natural fuel can serve as a promising photocatalyst for the degradation of organic pollutants in the environment. Further studies can be conducted to investigate their potential in other applications.

Antimicrobial photodynamic therapy with erythrosine and blue light on dental biofilm bacteria: study protocol for randomised clinical trial.

INTRODUCTION: The objective is to investigate the effect of antimicrobial photodynamic therapy (aPDT) mediated by erythrosine and a blue light-emitting diode (LED) in the reduction of bacteria in dental biofilm. METHODS AND ANALYSIS: This clinical trial will be conducted with 30 patients who have biofilm, but without the presence of periodontal pockets, and who are being treated at the Dental Clinic of Universidade Metropolitana de Santos. A split-mouth model will be used (n=30), with group 1 control (conventional treatment) and group 2 (conventional treatment and aPDT). The bicarbonate jet will be used to remove dental biofilm in both groups. The treatment will be carried out in one session. aPDT will be performed before cleaning/prophylaxis, only in group 2. Participants will rinse with the photosensitiser erythrosine (diluted to 1 mM) for 1 min of pre-irradiation time, so that the drug can stain all the bacterial biofilm. Then, the D-2000 LED (DMC) will be applied, emitting at a wavelength of ʎ=470 nm, radiant power of 1000 mW, irradiance of 0.532 W/cm2 and radiant exposure of 63.8 J/cm2. Irradiation will be performed until the biofilm of the cervical region is illuminated for 2 min/point (4 cm2). The microbiological examination will be performed from samples of supragingival biofilm collected from the gingival sulcus. Collection will be performed in each experimental site before irradiation, immediately after the irradiation procedure and after the prophylaxis. Colony-forming units will be counted and the data will be submitted for statistical analysis for comparison of pretreatment and post-treatment results and between groups (conventional X aPDT). ETHICS AND DISSEMINATION: This study has been approved by the Ethics Committee of Universidade Metropolitana de Santos under process number 66984123.0.0000.5509. Results will be published in peer-reviewed journals and will be presented at conferences. TRIAL REGISTRATION NUMBER: NCT05805761.

Utility of the food colorant erythrosine B as an effective green probe for quantitation of the anticancer sunitinib. Application to pharmaceutical formulations and human plasma.

Sunitinib is a tyrosine kinase inhibitor used for the treatment of renal cell carcinoma and gastrointestinal stromal tumors. In this study, two spectroscopic methods, spectrofluorometric and spectrophotometric, were utilized to quantify sunitinib in different matrices. In method I, the native fluorescence of erythrosine B was quenched by forming ion-pair complex with increasing quantities of sunitinib. This approach was utilized for measuring sunitinib in its dosage forms and spiked plasma. After excitation at 528 nm, the quenching of fluorescence is linearly related to the concentration across the range of 0.05-0.5 µg mL-1 at 550 nm in Britton-Robinson buffer (pH 4.0), with a correlation value of 0.9999 and a high level of sensitivity with detection limit down to 10 ng mL-1 . Method II relies on spectrophotometric measurements of the produced complex at 550 nm across a range of 0.5-10.0 µg mL-1 , with good correlation value of 0.9999. This method has a detection limit down to 0.16 µg mL-1 . The proposed methodologies were validated according to International Conference on Harmonization (ICH) guidelines with satisfactory results. The stoichiometry of the reaction was determined through the application of Job's method, while the mechanism of quenching was investigated by employing the Stern-Volmer plot. The designated methods were used to estimate sunitinib in its capsules and in spiked human plasma. Additionally, the statistical analysis of the data revealed no substantial differences when compared to previous reported spectroscopic method. Green assessment tools provide further details about the eco-friendly nature of the methods.

Efficient Degradation of Intracellular Antibiotic Resistance Genes by Photosensitized Erythrosine-Produced 1O2.

Intracellular antibiotic resistance genes (iARGs) constitute the important part of wastewater ARGs and need to be efficiently removed. However, due to the dual protection of intracellular DNA by bacterial membranes and the cytoplasm, present disinfection technologies are largely inefficient in iARG degradation. Herein, we for the first time found that erythrosine (ERY, an edible dye) could efficiently degrade iARGs by producing abundant 1O2 under visible light. Seven log antibiotic-resistant bacteria were inactivated within only 1.5 min, and 6 log iARGs were completely degraded within 40 min by photosensitized ERY (5.0 mg/L). A linear relationship was established between ARG degradation rate constants and 1O2 concentrations in the ERY photosensitizing system. Surprisingly, a 3.2-fold faster degradation of iARGs than extracellular ARGs was observed, which was attributed to the unique indirect oxidation of iARGs induced by 1O2. Furthermore, ERY photosensitizing was effective for iARG degradation in real wastewater and other photosensitizers (including Rose Bengal and Phloxine B) of high 1O2 yields could also achieve efficient iARG degradation. The findings increase our knowledge of the iARG degradation preference by 1O2 and provide a new strategy of developing technologies with high 1O2 yield, like ERY photosensitizing, for efficient iARG removal.

Validated spectrofluorimetric and resonance Rayleigh scattering methods for determining naftidrofuryl in varied pharmaceutical samples based on its interaction with erythrosin B.

Naftidrofuryl is a vasodilator medication used for treating cerebral and peripheral vascular diseases. In this study, two spectroscopical techniques, spectrofluorimetric and resonance Rayleigh scattering (RRS), were utilized to quantify naftidrofuryl in its pharmaceutical samples. The developed methodologies in this study rely on a facile process of forming an association complex between erythrosine B reagent and naftidrofuryl under acidic conditions. The fluorimetric assay is based on the ability of naftidrofuryl to quench and decrease the native fluorescence intensity of the reagent when measured at λ emis . = 550 nm ( λ excit . = 526 nm). Under similar reaction conditions, the RRS method relies on the observed amplification in the RRS spectrum of the reagent at a wavelength of 577 nm following its interaction with naftidrofuryl. The methods exhibited linearity within the ranges 0.2-1.6 µg/ml (r2  = 0.999) and 0.1-1.4 µg/ml (r2  = 0.9994), with limit of quantitation values of 0.146 and 0.099 µg/ml, and limit of detection values of 0.048 and 0.032 µg/ml, for the fluorometric and the RRS methods, respectively. Moreover, the quenching between the dye and naftidrofuryl was studied using Stern-Volmer analysis, and the methodologies were experimentally optimized and validated. Additionally, acceptable recoveries were achieved when the procedures were applied to determine naftidrofuryl in pharmaceutical samples.

Food-Grade Physically Unclonable Functions.

Counterfeit products in the pharmaceutical and food industries have posed an overwhelmingly increasing threat to the health of individuals and societies. An effective approach to prevent counterfeiting is the attachment of security labels directly on drugs and food products. This approach requires the development of security labels composed of safely digestible materials. In this study, we present the fabrication of security labels entirely based on the use of food-grade materials. The key idea proposed in this study is the exploitation of food-grade corn starch (CS) as an encoding material based on the microscopic dimensions, particulate structure, and adsorbent characteristics. The strong adsorption of a food colorant, erythrosine B (ErB), onto CS results in fluorescent CS@ErB microparticles. Randomly positioned CS@ErB particles can be obtained simply by spin-coating from aqueous solutions of tuned concentrations followed by transfer to an edible gelatin film. The optical and fluorescence microscopy images of randomly positioned particles are then used to construct keys for a physically unclonable function (PUF)-based security label. The performance of PUFs evaluated by uniformity, uniqueness, and randomness analysis demonstrates the strong promise of this platform. The biocompatibility of the fabricated PUFs is confirmed with assays using murine fibroblast cells. The extremely low-cost and sustainable security primitives fabricated from off-the-shelf food materials offer new routes in the fight against counterfeiting.

Production of singlet oxygen from photosensitizer erythrosine for facile inactivation of coronavirus on mask.

The global health crisis caused by the COVID-19 pandemic has led to a surge in demand and use of personal protective equipment (PPE) such as masks, putting great pressure on social production and the environment.It is urgent to find an efficient and non-destructive disinfection method for the safe reuse of PPE. This study proposes a PPE disinfection method that uses erythrosine, a U.S. Food and Drug Administration-approved food dye, as photosensitizer to produce singlet oxygen for virus inactivation, and indicates the completion of disinfection by its photobleaching color change.After spraying 100 µL of 10 µM erythrosine on the surface of the mask for 3 times and light exposure for 25 min, the titer of coronavirus decreased by more than 99.999%, and the color of erythrosine on the mask surface disappeared. In addition, the structure of the mask was intact and the filtration efficiency was maintained at > 95% after 10 cycles of erythrosine treatment.Therefore, this disinfection method can provide at least 10 cycles of reuse with the advantages of high safety and convenient, and the completion of disinfection can be indicated by its photobleaching, which is suitable for hospitals and daily life to reduce the consumption of PPE.

Visible-Light-Mediated Regioselective C3-H Selenylation of Pyrazolo[1,5-a]pyrimidines Using Erythrosine B as Photocatalyst.

A visible-light-induced efficient methodology has been developed for the C-H selenylation of pyrazolo[1,5-a]pyrimidine derivatives employing erythrosine B as the photocatalyst. This is the first report on the regioselective selenylation of pyrazolo[1,5-a]pyrimidines. The efficiency of this methodology for the selenylation of different electron-rich heterocycles like pyrazole, indole, imidazo[1,2-a]pyridine, imidazo[2,1-b]thiazole, and 4-(phenylamino)-2H-chromen-2-one has been also demonstrated. The exploration of erythrosine B as a photocatalyst with a simple and mild procedure, wide substrate scope, and practical applicability and the employment of eco-friendly energy, oxidant, and solvent are the attractive characteristics of this methodology.