Colorimetric Detection of Cu2+ and Ag+ Ions Using Multi-Responsive Schiff Base Chemosensor: A Versatile Approach for Environmental Monitoring.

In this study, we have synthesized a novel Schiff base-centered chemosensor, designated as SB, with the chemical name ((E)-1-(((6-methylbenzo[d]thiazol-2-yl) imino)methyl)naphthalen-2-ol). This chemosensor was structurally characterized by FT-IR, 1H NMR, UV-Vis and fluorescence spectroscopy. After structural characterization the chemosensor SB was subsequently employed for the detection of Cu2+ and Ag+, using fluorescence spectroscopy. The chemosensor SB showed excellent ability to recognize the target metal ions, leading to fluorescence enhancement and color change from yellow to yellowish orange for Cu2+ and yellow to radish for Ag+ ions. The detection capabilities of this chemosensor were impressive, showing excellent selectivity and an exceptionally low detection limit of 0.0016 µM for Cu2+ and 0.00389 µM for Ag+. Most notably, our approach enables the quantitative detection both metal ions in different water and soil samples at trace level. This achievement holds great promise for analytical applications and offers significant contributions to the field of chemical sensing and environmental protection.

An ultrasensitive colorimetric and fluorescent "turn-on" chemosensor based on Schiff base for the detection of Cu2+ in the aqueous medium.

We designed and synthesized a fluorescent "turn-on" and colorimetric chemosensor ((E)-1-((p-tolylimino)methyl)naphthalen-2-ol) SB. The structure of the synthesized chemosensor was investigated by 1H NMR, FT-IR, and fluorescence spectroscopy, and its sensing properties were studied toward Mn2+, Cu2+, Pb2+, Cd2+, Na+, Ni2+, Al3+, K+, Ag+, Zn2+, Co2+, Cr3+, Hg2+, Ca2+, and Mg2+. SB showed an excellent colorimetric (yellow to yellowish brown) in MeOH and fluorescence "turn-on" sensing response to Cu2+ in MeOH/Water (10/90, v/v) media. The sensing mechanism of SB toward Cu2+ was investigated by FT-IR, 1H NMR titration, DFT studies, and Job's plot analysis. The detection limit was calculated to be very low 0.0025 µg mL-1 (0.0025 ppm). Furthermore, the test strip containing SB also showed excellent selectivity and sensitivity toward Cu2+ in a solution medium and when supported on a solid medium.

Heterocyclic Organic Compounds as a Fluorescent Chemosensor for Cell Imaging Applications: A Review.

Fluorometric determination of different biologically, industrially, and environmentally important analytes is a powerful technique because this technique has excellent selectivity, high sensitivity, rapid photoluminescence response, low cost, applicability to bioimaging, and low detection limit. Fluorescence imaging is a powerful technique for screening different analytes in the living system. Heterocyclic organic compounds have been extensively used as a fluorescence chemosensor for the determination of different biologically important cations like Co2+, Zn2+, Cu2+, Hg2+, Ag+, Ni2+, Cr3+, Al3+, Pd2+, Fe3+ Pt2+, Mn2+, Sn2+, Pd2+, Au3+, Pd2+, Cd2+, Pb2+ and other ions in biological and environmental systems. These compounds also showed significant biological applications such as anti-cancer, anti-ulcerogenic, antifungal, anti-inflammatory, anti neuropathic, antihistaminic, antihypertensive, analgesic, antitubercular, antioxidant, antimalarial, antiparasitic, antiglycation, antiviral anti-obesity, and antibacterial potency. In this review, we summarize the heterocyclic organic compounds based on fluorescent chemosensors and their applications in bioimaging studies for the recognition of different biologically important metal ions.

Barriers and facilitators of childhood COVID-19 vaccination among parents: A systematic review.

Background: The acceptance of vaccination against COVID-19 among parents of young children plays a significant role in controlling the current pandemic. A wide range of factors that influence vaccine hesitancy in adults has been reported worldwide, but less attention has been given to COVID-19 vaccination among children. Vaccine hesitancy is considered a major challenge in achieving herd immunity, and it is more challenging among parents as they remain deeply concerned about their child's health. In this context, a systematic review of the current literature is inevitable to assess vaccine hesitancy among parents of young children to ensure a successful ongoing vaccination program. Method: A systematic search of peer-reviewed English literature indexed in Google Scholar, PubMed, Embase, and Web of science was performed using developed keywords between 1 January 2020 and August 2022. This systematic review included only those studies that focused on parental concerns about COVID-19 vaccines in children up to 12 years without a diagnosis of COVID-19. Following PRISMA guidelines, a total of 108 studies were included. The quality appraisal of the study was performed by Newcastle-Ottawa Scale (NOS). Results: The results of 108 studies depict that vaccine hesitancy rates differed globally with a considerably large number of factors associated with it. The highest vaccine hesitancy rates among parents were reported in a study from the USA (86.1%) and two studies from Saudi Arabia (>85%) and Turkey (89.6%). Conversely, the lowest vaccine hesitancy rates ranging from 0.69 and 2% were found in two studies from South Africa and Switzerland, respectively. The largest study (n = 227,740) was conducted in Switzerland while the smallest sample size (n = 12) was represented by a study conducted in the USA. The most commonly reported barriers to childhood vaccination were mothers' lower education level (N = 46/108, 43%), followed by financial instability (N = 19/108, 18%), low confidence in new vaccines (N = 13/108, 12%), and unmonitored social media platforms (N = 5/108, 4.6%). These factors were significantly associated with vaccine refusal among parents. However, the potential facilitators for vaccine uptake among respondents who intended to have their children vaccinated include higher education level (N = 12/108, 11%), followed by information obtained through healthcare professionals (N = 9/108, 8.3%) and strong confidence in preventive measures taken by the government (N = 5/81, 4.6%). Conclusion: This review underscores that parents around the globe are hesitant to vaccinate their kids against COVID-19. The spectrum of factors associated with vaccine hesitancy and uptake varies across the globe. There is a dire need to address vaccine hesitancy concerns regarding the efficacy and safety of approved vaccines. Local context is inevitable to take into account while developing programs to reduce vaccine hesitancy. There is a dire need to devise strategies to address vaccine hesitancy among parents through the identification of attributing factors.

Green Synthesis and Characterization of Cobalt Oxide Nanoparticles Using Psidium guajava Leaves Extracts and Their Photocatalytic and Biological Activities.

The advanced technology for synthesizing nanoparticles utilizes natural resources in an environmentally friendly manner. Additionally, green synthesis is preferred to chemical and physical synthesis because it takes less time and effort. The green synthesis of cobalt oxide nanoparticles has recently risen due to its physico-chemical properties. In this study, many functional groups present in Psidium guajava leaf extracts are used to stabilize the synthesis of cobalt oxide nanoparticles. The biosynthesized cobalt oxide nanoparticles were investigated using UV-visible spectroscopic analysis. Additionally, Fourier-transform infrared spectroscopy revealed the presence of carboxylic acids, hydroxyl groups, aromatic amines, alcohols and phenolic groups. The X-ray diffraction analysis showed various peaks ranging from 32.35 to 67.35°, and the highest intensity showed at 36.69°. The particle size ranged from 26 to 40 nm and confirmed the average particle size is 30.9 nm. The green synthesized P. guajava cobalt oxide nanoparticles contain cobalt as the major abundant element, with 42.26 wt% and 18.75 at% confirmed by the EDAX techniques. SEM images of green synthesized P. guajava cobalt oxide nanoparticles showed agglomerated and non-uniform spherical particles. The anti-bacterial activity of green synthesized P. guajava cobalt oxide nanoparticles was evaluated against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli with a 7 to 18 mm inhibitory zone. The photocatalytic activity was evaluated using green synthesized P. guajava cobalt oxide nanoparticles and observed 79% of dye degradation. The MTT assay of P. guajava cobalt oxide nanoparticles showed an excellent cytotoxic effect against MCF 7 and HCT 116 cells compared to normal cells. The percentage of cell viability of P. guajava cobalt oxide nanoparticles was observed as 90, 83, 77, 68, 61, 58 and 52% for MCF-7 cells and 82, 70, 63, 51, 43, 40, and 37% for HCT 116 cells at the concentration of 1.53, 3.06, 6.12, 12.24, 24.48, 50, and 100 µg/mL compared to control cells. These results confirmed that green synthesized P. guajava cobalt oxide nanoparticles have a potential photocatalytic and anti-bacterial activity and also reduced cell viability against MCF-7 breast cancer and HCT 116 colorectal cancer cells.

Efficient liquid phase confiscation of nile blue using a novel hybrid nanocomposite synthesized from guar gum-polyacrylamide and erbium oxide.

In recent times, biopolymer-metal oxide nanocomposites have gained prominent importance in the attenuation of environmental toxicants from aqueous phase. But lanthanide oxide-based biopolymer nanocomposites have scantly been evaluated for their adsorption potential. A novel guar gum-polyacrylamide/erbium oxide nanocomposite (GG-PAAm/Er2O3 NC) adsorbent was synthesized by copolymerization of guar gum (GG) and acrylamide (AAm) utilizing N-N'-methylenebisacrylamide as a crosslinker and Er2O3 as a reinforcing agent. The adsorptive efficacy of GG-PAAm/Er2O3 nanocomposite was evaluated using nile blue (NB) as a model pollutant dye from aquatic system. The prepared adsorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, Brunauer-Emmett-Teller (BET) analysis, thermogravimetric analysis, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), and high-resolution transmission electron microscopy (HRTEM). The optimal process parameters, which include dosage (0.8 g/L), agitation time (40 min), initial solution pH (6), and initial NB concentration (80 mg/L) were determined by batch methodology. The equilibrium data for NB confiscation was better expressed by Langmuir isotherm model, with maximal adsorption effectiveness (Qm) of 225.88 mg NB/g demonstrating the actively monolayer adsorption onto homogeneous surface of GG-PAAm/Er2O3 NC. The kinetics of NB sorption process onto GG-PAAm/Er2O3 NC was reliable with pseudo-second order model. Thermodynamic parameters such as ΔH° (15-17 kJ/mol) and ΔS° (0.079-0.087 kJ/mol/K), and - ΔG° (8.81-10.55 kJ/mol) for NB validated the endothermic, an increased randomness at the GG-PAAm/Er2O3-NB interface, and spontaneity and feasibility of the process, respectively. The spent nanocomposite was effectively regenerated with NaOH, and could be reused proficiently for five runs demonstrating the high reusability potential of the nanocomposite. The commendable removal efficiency and high reusability of GG-PAAm/Er2O3 NC recommended it to be a highly competent adsorbent for cationic dyes particularly NB diminution from aqueous waste.

Sustainable Green Synthesis of Yttrium Oxide (Y2O3) Nanoparticles Using Lantana camara Leaf Extracts: Physicochemical Characterization, Photocatalytic Degradation, Antibacterial, and Anticancer Potency.

Due to their appropriate physicochemical properties, nanoparticles are used in nanomedicine to develop drug delivery systems for anticancer therapy. In biomedical applications, metal oxide nanoparticles are used as powerful and flexible multipurpose agents. This work described a green synthesis of Y2O3 nanoparticles (NPs) using the sol-gel technique with the use of aqueous leaf extracts of Lantana camara L (LC). These nanoparticles were characterized with the aid of different methods, including UV, X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), transmitted electron microscopy (TEM), and photocatalytic degradation. Y2O3 nanoparticles showed excellent antibacterial activity against Gram-positive Bacillus subtilis and Gram-negative Escherichia coli with a 10 to 15 mm inhibitory zone. Green Y2O3 NPs were released with a 4 h lag time and 80% sustained release rate, indicating that they could be used in drug delivery. In addition, the bioavailability of green Y2O3 NPs was investigated using cell viability in cervical cancer cell lines. These green-synthesized Y2O3 NPs demonstrated photocatalytic degradation, antibacterial, and anticancer properties.

Medicinal Importance and Chemosensing Applications of Pyridine Derivatives: A Review.

Pyridine derivatives are the most common and significant heterocyclic compounds, which play an important role in various fields ranging from medicinal to chemosensing applications. Pyridine derivatives possess different biological activities such as antifungal, antibacterial, antioxidant, antiglycation, analgesic, antiparkinsonian, anticonvulsant, anti-inflammatory, ulcerogenic, antiviral, and anticancer activity. Furthermore, these derivatives have a high affinity for various ions and neutral species and can be used as a highly effective chemosensor for the determination of different species. In this review article, generally used synthetic routes of pyridine, structural characterization, medicinal applications, and potential of pyridine derivatives in analytical chemistry as chemosensors have been discussed. We hope this study will support the new thoughts to design biological active compounds and highly selective and effective chemosensors for the detection of various species (anions, cations, and neutral species) in various samples (environmental, agricultural, and biological).

Statistical evaluation of liquid phase sequestration of acridine orange and Cr6+ by novel mesoporous glutamic acid-g-polyacrylamide/plaster of paris/riboflavin hydrogel nanocomposite.

The adsorption of acridine orange and Cr6+ ion onto plaster of paris reinforced glutamic acid-grafted-polyacrylamide hydrogel nanocomposite modified with riboflavin, Glu-g-PAM/POP/Rb HNC was studied. The Glu-g-PAM/POP/Rb HNC was physico-chemically characterized by Fourier transform infrared spectroscopy, X-ray diffraction analysis, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, transmission electron microscopy and Brunauer-Emmett-Teller analysis. The specific surface area, pore volume and pore diameter were 15.48 m2/g, 0.015 cm3/g and 4.23 nm, respectively. Adsorption process was strategized by response surface methodology (RSM) based on a 3-level 5-factor (initial solution pH, contact time, adsorbent dose, initial adsorbate concentration and temperature) central composite design (CCD), and validity of the estimated parameters was statistically evaluated using analysis of variance (ANOVA). The optimized operating variables were: pH (AO = 10; Cr6+ = 4.15), contact time (AO = 60 min; Cr6+ = 59 min), adsorbent dose (0.8 g/L), initial adsorbate concentration (60 mg/L) and temperature (298 K). Isotherm results were coincident with Langmuir isotherm model. The experimental kinetic adsorption data was congruous with pseudo-second order model, with the uptake rate controlled by both intraparticle and liquid film diffusions. The relatively high Langmuir saturation capacity of 202.63 mg AO/g and 143.68 mg Cr6+/g, supported by the decent recyclability up to four times affirmed the promising performance of the adsorbent. The efficacy of the adsorbent for simultaneous removal of AO and Cr6+ from bi-component system was assessed. The possible adsorption mechanism mainly involved hydrogen bonding, van der Waals forces, electrostatic and π-π interactions. Adsorption of AO and Cr6+ onto Glu-g-PAM/POP/Rb HNC was feasible and exothermic as revealed by the thermodynamic parameters. The findings demonstrated superior adsorbent efficacy for the seizure of pollutants, particularly AO and Cr6+ from aqueous solution.

Formulation and Evaluation of Topical Nano-Lipid-Based Delivery of Butenafine: In Vitro Characterization and Antifungal Activity.

The present research work was designed to prepare butenafine (BN)-loaded bilosomes (BSs) by the thin-film hydration method. BN is a sparingly water-soluble drug having low permeability and bioavailability. BSs are lipid-based nanovesicles used to entrap water-insoluble drugs for enhanced permeation across the skin. BSs were prepared by the thin-film hydration method and optimized by the Box-Behnken design (BBD) using lipid (A), span 60 (B), and sodium deoxycholate (C) as independent variables. The selected formulation (BN-BSo) was converted into the gel using Carbopol 940 as a gelling agent. The prepared optimized gel (BN-BS-og) was further evaluated for the gel characterization, drug release, drug permeation, irritation, and anti-fungal study. The optimized bilosomes (BN-BSo) showed a mean vesicle size of 215 ± 6.5 nm and an entrapment efficiency of 89.2 ± 1.5%. The DSC study showed that BN was completely encapsulated in the BS lipid matrix. BN-BSog showed good viscosity, consistency, spreadability, and pH. A significantly (p < 0.05) high release (81.09 ± 4.01%) was achieved from BN-BSo compared to BN-BSog (65.85 ± 4.87%) and pure BN (17.54 ± 1.37 %). The permeation study results revealed that BN-BSo, BN-BSog, and pure BN exhibited 56.2 ± 2.7%, 39.2 ± 2.9%, and 16.6 ± 2.3%. The enhancement ratio of permeation flux was found to be 1.4-fold and 3.4-fold for the BN-BS-og and pure BN dispersion. The HET-CAM study showed that BN-BSog was found to be nonirritant as the score was found within the limit. The antifungal study revealed a significant (p < 0.05) enhanced antifungal activity against C. albicans and A. niger. The findings of the study revealed that BS is an important drug delivery system for transdermal delivery.

Synthesis, physicochemical characterization, and in vitro evaluation of biodegradable PLGA nanoparticles entrapped to folic acid for targeted delivery of kaempferitrin.

Polymeric nanoparticles are widely studied in the treatment of colorectal cancer. Kaempferitrin-loaded nontoxic and biodegradable poly(d,l-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) developed by the solvent emulsion evaporation method by improving its solubility and bioavailability. In order to improve the delivery of kaempferitrin (KM) to cancerous cells, folic acid (FA) combined kaempfertrin PLGA NPs were prepared. The goal of the study was whether PLGA NPs with surface KM and FA could help to prevent colorectal cancer. The synthesis of KM with FA in a nanomedicine could be crucial in the development of colon cancer chemotherapeutics. The physicochemical characteristics of synthesized KM-entrapped PLGA NPs were investigated by XRD, FTIR, zeta potential, and TEM. The KM + FA + PLGA NPs showed particle size with 132.9 ± 1.4 nm, zeta potential -15.0 ± 1.73 mV, encapsulation efficiency 67.92 ± 4.8, and drug-loading capacity 0.463 ± 0.173. In vitro cytotoxicity study on HT-29 cell lines using the MTT assay, the apoptotic study revealed that KM + FA + PLGA NPs have an enhanced cytotoxic effect compared to the KM + PLGA NPs drug solution. These findings suggested that KM + FA + PLGA NPs could be an effective chemotherapeutic drug delivery system in colon adenocarcinoma HT-29 cells.

Electron and proton magnetic resonance spectroscopic investigation of anthracene oxidation.

The work reports a method for monitoring anthracene radical-mediated oxidation reactions using electron paramagnetic resonance (EPR) spectroscopy. The formation of anthracene dimer product was well-defined using 1H-NMR and 1H-1H correlation spectroscopy (COSY). Unrestricted 3-21G/B3LYP DFT was used to estimate radical hyperfine spacing (hfs), then to identify the characteristic EPR-spin transitions of anthracene radical intermediate. A detailed investigation of an anthracene oxidation reaction and its possible reaction mechanism in concentrated sulphuric acid is conducted as a model system for polyaromatic hydrocarbons. Peak-to-peak (p2p) intensities of selected EPR-spectral lines were used to evaluate anthracene's oxidation kinetic model. The findings showed that radical intermediate formation is a unimolecular autocatalytic process, dimerization is a pseudo-zero-order reaction, and the latter is the rate-determining step with a half-life of 48 ± 2 min at 25.0 °C.

Bioactive Molecules of Mandarin Seed Oils Diminish Mycotoxin and the Existence of Fungi.

Mandarin is a favorite fruit of the citrus family. Mandarin seeds are considered a source of nontraditional oil obtained from byproduct materials. This investigation aimed to assess the biomolecules of mandarin seeds and evaluated their antimycotic and antimycotoxigenic impact on fungi. Moreover, it evaluated the protective role of mandarin oil against aflatoxin toxicity in cell lines. The two types of extracted oil (fixed and volatile) were ecofriendly. The fatty acid composition, tocopherol, sterols, and carotenoids were determined in the fixed oil, whereas volatiles and phenolics were estimated in the essential oil. A mixture of the two oils was prepared and evaluated for its antimicrobial impact. The reduction effect of this mixture was also investigated to reduce mycotoxin secretion using a simulated experiment. The protective effect of the oil was evaluated using healthy strains of cell lines. Fixed oil was distinguished by the omega fatty acid content (76.24%), lutein was the major carotenoid (504.3 mg/100 g) and it had a high ß-sitosterol content (294.6 mg/100 g). Essential oil contained limonene (66.05%), α-pinene (6.82%), ß-pinene (4.32%), and γ-terpinene (12.31%) in significant amounts, while gallic acid and catechol were recorded as the dominant phenolics. Evaluation of the oil mix for antimicrobial potency reflected a considerable impact against pathogenic bacteria and toxigenic fungi. By its application to the fungal media, this oil mix possessed a capacity for reducing mycotoxin secretion. The oil mix was also shown to have a low cytotoxic effect against healthy strains of cell lines and had potency in reducing the mortality impact of aflatoxin B1 applied to cell lines. These results recommend further study to involve this oil in food safety applications.

Antioxidant and Antimicrobial Evaluation and Chemical Investigation of Rosa gallica var. aegyptiaca Leaf Extracts.

Rosa gallica var. aegyptiaca is a species of flowering plant belonging to the Rosaceae family that plays an important role as a therapeutic agent for the treatment of specific types of cancer, microbial infections, and diabetes mellitus. This work presents the first report on the evaluation of the antioxidant and antimicrobial potential along with the phytochemical analysis of Rosa gallica var. aegyptiaca leaves. Five leaf extracts of hexane, chloroform, methanol, hydromethanol 80%, and water were prepared. Assessment of antioxidant activity was carried out via DPPH radical scavenging assay. Antimicrobial activity against five foodborne pathogenic bacteria-including Listeria monocytogenes, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Salmonella enteritidis-and the fungus Candida albicans, was examined using the disc diffusion method. Total phenolic content and total flavonoid content were determined using the Folin-Ciocalteu reagent and aluminum chloride methods, respectively. Isolation, identification, and quantification of phenolic compounds were performed using HPLC-DAD analysis. Amongst the five leaf extracts that were investigated, hydromethanol 80% extract possessed the highest extraction yield, antioxidant activity, total phenolic content, and antimicrobial activity against all tested microbial strains. Moreover, this extract furnished six active phenolic compounds: gallic acid (1), (+) catechin (2), chlorogenic acid (3), (-) epicatechin (4), quercetin-3-O-α-d-(glucopyranoside) (5), and quercetin (6). This study provides an alternative utilization of R. gallica var. aegyptiaca leaves as a readily accessible source of natural antioxidants and antimicrobials in the food and pharmaceutical industries.

Efficacy of Bottle Gourd Seeds' Extracts in Chemical Hazard Reduction Secreted as Toxigenic Fungi Metabolites.

Bottle gourd seeds are surrounded by innumerable bioactive components of phytochemicals. This work aimed to evaluate the effectiveness of bottle gourd extracts as antimicrobial and an-ti-mycotoxigenic against toxigenic fungi and mycotoxins. Polar and nonpolar extracts were made from the seeds. The polar eco-friendly extract was prepared by an ultrasonication-assisted technique utilizing aqueous isopropanol (80%), whereas the non-polar extract was obtained using petroleum ether (40-60). The antioxidant efficacy, total phenolic content, and flavonoid content of the extracts were all measured. The fatty acid profile was measured using GC equipment, and the influence on toxigenic fungus and mycotoxin release was also investigated. The antioxidant efficacy of the polar extract is reflected. The total phenolic values of the oil and polar extract were 15.5 and 267 mg of GAE/g, respectively. The total flavonoid content of the oil was 2.95 mg catechol/g, whereas the isopropyl extract of seeds contained 14.86 mg catechol/g. The polar extract inhibited the DPPH more effectively than oil. When compared to other seed oils, the fatty acid composition differed. The pathogens were distinguished by the MIC and MFC for the polar extract. Three sterols were found in the oil, with a high concentration of B-sitosterols. The oil's valuable -carotene content and tocopherol content were recorded. When compared to traditional antibiotics, the polar extract has shown promising antimicrobial activity against infections and toxigenic fungi. Bottle gourd extracts, as a non-traditional bioactive source, are viewed as a potentially promising alternative that might contribute to increased food safety, shelf-life, and security.

The Effect of Wall Material Type on the Encapsulation Efficiency and Oxidative Stability of Fish Oils.

Fish oil is the primary source of long-chain omega-3 fatty acids, which are important nutrients that assist in the prevention and treatment of heart disease and have many health benefits. It also contains vitamins that are lipid-soluble, such as vitamins A and D. This work aimed to determine how the wall material composition influenced the encapsulation efficiency and oxidative stability of omega fish oils in spray-dried microcapsules. In this study, mackerel, sardine waste oil, and sand smelt fish oil were encapsulated in three different wall materials (whey protein, gum Arabic (AG), and maltodextrin) by conventional spray-drying. The effect of the different wall materials on the encapsulation efficiency (EE), flowability, and oxidative stability of encapsulated oils during storage at 4 °C was investigated. All three encapsulating agents provided a highly protective effect against the oxidative deterioration of the encapsulated oils. Whey protein was found to be the most effective encapsulated agent comparing to gum Arabic and maltodextrin. The results indicated that whey protein recorded the highest encapsulation efficiency compared to the gum Arabic and maltodextrin in all encapsulated samples with EE of 71.71%, 68.61%, and 64.71% for sand smelt, mackerel, and sardine oil, respectively. Unencapsulated fish oil samples (control) recorded peroxide values (PV) of 33.19, 40.64, and 47.76 meq/kg oil for sand smelt, mackerel, and sardine oils after 35 days of storage, while all the encapsulated samples showed PV less than 10 in the same storage period. It could be concluded that all the encapsulating agents provided a protective effect to the encapsulated fish oil and elongated the shelf life of it comparing to the untreated oil sample (control). The results suggest that encapsulation of fish oil is beneficial for its oxidative stability and its uses in the production of functional foods.

Encapsulation Capacity of ß-Cyclodextrin Stabilized Silver Nanoparticles towards Creatinine Enhances the Colorimetric Sensing of Hydrogen Peroxide in Urine.

The ß-cyclodextrin shell of synthesized silver nanoparticles (ßCD-AgNPs) are found to enhance the detection of hydrogen peroxide in urine when compared to the Horse Radish Peroxidase assay kit. Nanoparticles are confirmed by the UV-Vis absorbance of their localized surface plasmonic resonance (LSPR) at 384 nm. The mean size of the ßCD-AgNPs is 53 nm/diameter; XRD analysis shows a face-centered cubic structure. The crystalline structure of type 4H hexagonal nature of the AgNPs with 2.4 nm ß-CD coating onto is confirmed using aberration corrected high-resolution transmission electron microscopy (HRTEM). A silver atomic lattice at 2.50 Å and 2.41 Å corresponding to (100) and (101) Miller indices is confirmed using the HRTEM. The scope of ßCD-AgNPs to detect hydrogen peroxide (H2O2) in aqueous media and human urine is investigated. The test is optimized by examining the effect of volumes of nanoparticles, the pH of the medium, and the kinetic and temperature effect on H2O2 detection. The ßCD-AgNPs test is used as a refined protocol, which demonstrated improved sensitivity towards H2O2 in urine compared to the values obtained by the Horse Radish Assay kit. Direct assessment of H2O2 by the ßCD-AgNPs test presented always with a linear response in the nM, µM, and mM ranges with a limit of detection of 1.47 nM and a quantitation limit of 3.76 nM. While a linear response obtained from 1.3 to 37.3 nmoles of H2O2/mole creatinine with a slope of 0.0075 and regression coefficient of 0.9955 when the ßCD-AgNPs is used as refined test of creatinine. Values ranging from 34.62 ± 0.23 nmoles of H2O2/mole of creatinine and 54.61 ± 1.04 nmoles of H2O2/mole of creatinine when the matrix is not diluted and between 32.16 ± 0.42 nmoles of H2O2/mole of creatinine and 49.66 ± 0.80 nmoles of H2O2/mole of creatinine when the matrix is twice diluted are found in freshly voided urine of seven apparent healthy men aged between 20 and 40 years old.

Design and Characterization of Electrochemical Sensor for the Determination of Mercury(II) Ion in Real Samples Based upon a New Schiff Base Derivative as an Ionophore.

The present paper provides a description of the design, characterization, and use of a Hg2+ selective electrode (Hg2+-SE) for the determination of Hg2+ at ultra-traces levels in a variety of real samples. The ionophore in the proposed electrode is a new Schiff base, namely 4-bromo-2-[(4-methoxyphenylimino)methyl]phenol (BMPMP). All factors affecting electrode response including polymeric membrane composition, concentration of internal solution, pH sample solution, and response time were optimized. The optimum response of our electrode was obtained with the following polymeric membrane composition (% w/w): PVC, 32; o-NPOE, 64.5; BMPMP, 2 and NaTPB, 1.5. The potentiometric response of Hg2+-SE towards Hg2+ ion was linear in the wide range of concentrations (9.33 × 10-8-3.98 × 10-3 molL-1), while, the limit of detection of the proposed electrode was 3.98 × 10-8 molL-1 (8.00 µg L-1). The Hg2+-SE responds quickly to Hg2+ ions as the response time of less than 10 s. On the other hand, the slope value obtained for the developed electrode was 29.74 ± 0.1 mV/decade in the pH range of 2.0-9.0 in good agreement with the Nernstian response (29.50 mV/decade). The Hg2+-SE has relatively less interference with other metal ions. The Hg2+-SE was used as an indicator electrode in potentiometric titrations to estimate Hg2+ ions in waters, compact fluorescent lamp, and dental amalgam alloy and the accuracy of the developed electrode was compared with ICP-OES measurement values. Moreover, the new Schiff base (BMPMP) was synthesized and characterized using ATR-FTIR, elemental analysis, 1H NMR, and 13C NMR. The PVC membranes containing BMPMP as an ionophore unloaded and loaded with Hg(II) are reported by scanning electron microscope images (SEM) along with energy-dispersive X-ray spectroscopy (EDX) spectra.

Efficiency enhancement of the spectrophotometric estimation of cobalt in waters and pharmaceutical preparations using dispersive liquid-liquid microextraction and microcells with long optical paths.

In this paper, dispersive liquid-liquid microextraction (DLLME), long optical path microcells, and a selective chromogenic reagent were employed to improve the analytical efficiency of cobalt determination by spectrophotometry. The methodology proposed in the present study is based upon the microextraction of a cobalt(II) complex with 1-[4-[(2-hydroxynaphthalen-1-yl)methylideneamino] phenyl]ethanone (HNE) by DLLME and measurement of the absorbance of the sedimented phase using a microcell with an optical path length of 50 mm (Microcell-50). DLLME was performed using a binary mixture containing 900 µL of methanol as a dispersing solvent and 400 µL of CHCl3 (extraction solvent) at pH 6-8 adjusted by a mixture of HCl and NaOH. The electronic spectrum of the dark brown complex recorded in the sedimented phase using Microcell-50 shows a well-defined peak at λmax 324 ± 3 nm with a molar absorptivity of 1.08 × 106 M-1 cm-1. Cobalt was monitored at a detection limit (LOD) of 0.08 µg L-1 and in the linear concentration range of 0.45-10 µg L-1, while the limit of quantitation (LOQ), relative standard deviation (RSD), and the enhancement factor (EF) were 0.264, 1.6 µgL-1, and 223, respectively. Our method was evaluated by determining cobalt in certified reference materials and experimental samples, and the results were compared with ICP-MS measurements. Moreover, the chemical structure of the [Co(C38H28O2N)2] complex was suggested through using different characterization techniques such as Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thermal analysis, and powder X-ray diffraction.

Synergistic Impact of Bioactive Byproduct Extract Leads to Anti-Fusarium and Anti-Mycotoxin Secretion.

Fruit byproducts are considered a high source of bioactive molecules, which possess antioxidant activities. These antioxidants play principal functions in mycotoxin reduction. This study aimed to evaluate crude mandarin byproduct extract for its chemical interaction with fungal growth and suppression of mycotoxin production, and to illustrate whether the impact was regarding individual molecules or a synergistic antioxidation process. Extract contents were analyzed for their phenolic, flavonoids, and antioxidant activity. The fatty acid composition and volatile components were determined using the GC apparatus. The influence of the extract evaluated versus the standard phenolics of trans-ferulic and hesperidin were evaluated. The liposome technique was applied to prevent the antioxidant properties of the bioactive extract. The anti-mycotoxigenic effects of the liposomal and non-liposomal extract were determined in fungal media against the standard phenolics. The results manifested ferulic (235.54 ± 3.34 mg/100 g) and hesperidin (492.11 ± 1.15 mg/100 g) as high phenolics in the extract. Limonene was the main volatile (67.54 ± 1.74%), as well antioxidant activities determined in considerable values. The crude extract recorded efficiency as an anti-Fusarium agent, but less than the standard hesperidin applied in fungal media. The bioactive extract recorded possessed a reduction influence on mycotoxin production. The impact may be joining with its fungal inhibition or its component activity with the active groups on the mycotoxin molecule. The formation of liposomal extract enhanced its efficacy in mycotoxin reduction. This enhancement may illustrate its protective properties for antioxidant components of the bioactive extract.