Recent advancements in modifications of metal-organic frameworks-based materials for enhanced water purification and contaminant detection.

Metal-organic frameworks (MOFs) have emerged as a key focus in water treatment and monitoring due to their unique structural features, including extensive surface area, customizable porosity, reversible adsorption, and high catalytic efficiency. While numerous reviews have discussed MOFs in environmental remediation, this review specifically addresses recent advancements in modifying MOFs to enhance their effectiveness in water purification and monitoring. It underscores their roles as adsorbents, photocatalysts, and in luminescent and electrochemical sensing. Advancements such as pore modification, defect engineering, and functionalization, combined synergistically with advanced materials, have led to the development of recyclable MOF-based nano-adsorbents, Z-scheme photocatalytic systems, nanocomposites, and hybrid materials. These innovations have broadened the spectrum of removable contaminants and improved material recyclability. Additionally, this review delves into the creation of multifunctional MOF materials, the development of robust MOF variants, and the simplification of synthesis methods, marking significant progress in MOF sensor technology. Furthermore, the review addresses current challenges in this field and proposes potential future research directions and practical applications. The growing research interest in MOFs underscores the need for an updated synthesis of knowledge in this area, focusing on both current challenges and future opportunities in water remediation.

Design and Fabrication of Biomass Derived Black Carbon Modified g-C3N4/FeIn2S4 Heterojunction as Highly Efficient Photocatalyst for Wastewater Treatment.

The environmental deterioration caused by dye wastewater discharge has received considerable attention in recent decades. One of the most promising approaches to addressing the aforementioned environmental issue is the development of photocatalysts with high solar energy consumption efficiency for the treatment of dye-contaminated water. In this study, a novel low-cost π-π biomass-derived black carbon modified g-C3N4 coupled FeIn2S4 composite (i.e., FeInS/BC-CN) photocatalyst is successfully designed and fabricated that reveals significantly improved photocatalytic performance for the degradation of Eosin Yellow (EY) dye in aqueous solution. Under dark and subsequent visible light irradiation, the amount optimized composite reveals 99% removal performance for EY dye, almost three-fold compared to that of the pristine FeInS and BC-CN counterparts. Further, it is confirmed by means of the electron spin resonance spectrometry, quenching experiments, and density functional theory (DFT) calculations, that the hydroxyl radicals (•OH) and superoxide radicals (•O2 -) are the dominant oxidation species involved in the degradation process of EY dye. In addition, a systematic photocatalytic degradation route is proposed based on the resultant degradation intermediates detectedduring liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. This work provides an innovative idea for the development of advanced photocatalysts to mitigate water pollution.

Optimization of the photocatalytic degradation of phenol using superparamagnetic iron oxide (Fe3O4) nanoparticles in aqueous solutions.

The present work was carried out to remove phenol from aqueous medium using a photocatalytic process with superparamagnetic iron oxide nanoparticles (Fe3O4) called SPIONs. The photocatalytic process was optimized using a central composite design based on the response surface methodology. The effects of pH (3-7), UV/SPION nanoparticles ratio (1-3), contact time (30-90 minutes), and initial phenol concentration (20-80 mg L-1) on the photocatalytic process were investigated. The interaction of the process parameters and their optimal conditions were determined using CCD. The statistical data were analyzed using a one-way analysis of variance. We developed a quadratic model using a central composite design to indicate the photocatalyst impact on the decomposition of phenol. There was a close similarity between the empirical values gained for the phenol content and the predicted response values. Considering the design, optimum values of pH, phenol concentration, UV/SPION ratio, and contact time were determined to be 3, 80 mg L-1, 3, and 60 min, respectively; 94.9% of phenol was eliminated under the mentioned conditions. Since high values were obtained for the adjusted R2 (0.9786) and determination coefficient (R2 = 0.9875), the response surface methodology can describe the phenol removal by the use of the photocatalytic process. According to the one-way analysis of variance results, the quadratic model obtained by RSM is statistically significant for removing phenol. The recyclability of 92% after four consecutive cycles indicates the excellent stability of the photocatalyst for practical applications. Our research findings indicate that it is possible to employ response surface methodology as a helpful tool to optimize and modify process parameters for maximizing phenol removal from aqueous solutions and photocatalytic processes using SPIONs.

Rice Nutraceuticals and Bioactive Compounds: Extraction, Characterization and Antioxidant Activity: A Review.

Rice (Oryza sativa L.), a cereal grass, belongs to the genus Oryza from the family Poaceae, which encompasses twenty-five species cultured in many countries of Asia, and partly in the rest of the world. From these species, two viz. Oryza sativa (O. sativa) Asian rice and Oryza glaberrima (O. glaberrima) African rice are commonly found and the most widely consumed staple food by a large part of the human population in the world, especially in Asia due to their nutritional and nutraceutical prospects. Rice, a popular source of carbohydrates, also contains a good amount of dietary fiber, minerals (Ca, Zn, Se, P, K, Mg, Fe, and Mn), protein and vitamin B along with several other medicinally important bioactives such as tocols (α-tocopherols and α-tocotrienols) (ßsitosterol) phenolic acids, flavonoids (apiginine), and oryzanol (24-Methylenecylcoartanyl transferulate). Rice bran is a byproduct of the rice polishing industry and is valuable in terms of containing 15-20% high-value oil. Because of the natural antioxidants present in rice, several medicinal benefits and biological properties can be attributed to rice consumption. The nutrient profile of rice varies based on several factors, such as grains (white, brown, red, and black/purple), the extent of polishing, and the preparation method. Considering the importance of rice as a traditional diet rich in high-value bioactives, together with the existing gap of related information, it is worthwhile to assemble a comprehensive review that focuses on the detailed profile of valuable nutrients and high-value phytochemicals and biological activities of rice to explore its functional food and nutraceutical applications. This review attempts to provide collective information on the essential rice cereal for its nutritional and antioxidant potential.

Metal organic frameworks as promising sensing tools for electrochemical detection of persistent heavy metal ions from water matrices: A concise review.

Water bodies are being polluted rapidly by disposal of toxic chemicals with their huge entrance into drinking water supply chain. Among these pollutants, heavy metal ions (HMIs) are the most challenging one due to their non-biodegradability, toxicity, and ability to biologically hoard in ecological systems, thus posing a foremost danger to human health. This can be addressed by robust, sensitive, selective, and reliable sensing of metal ions which can be achieved by Metal organic frameworks (MOF) based electrochemical sensors. In the present era, MOFs have caught greater interest in a variety of applications including sensing of hazardous pollutants such as heavy metal ions. So, in this review article, types, synthesis and working mechanism of MOF based sensors is explained to give general overview with updated literature. First time, detailed study is done for sensing of metal ions such as chromium, mercury, zinc, copper, manganese, palladium, lead, iron, cadmium and lanthanide by MOFs based electrochemical sensors. The use of MOFs as electrochemical sensors has attractive success story along with some challenges of the area. Considering these challenges, we attempted to highlight the milestone achieved and shortcomings along with future prospective of the MOFs for employing it in electrochemical sensing devices for HMIs. Finally, challenges and future prospects have been discussed to promote the development of MOFs-based sensors in future.

Enhanced Antifungal and Wound Healing Efficacy of Statistically Optimized, Physicochemically Evaluated Econazole-Triamcinolone Loaded Silica Nanoparticles.

Co-encapsulated econazole nitrate-triamcinolone acetonide loaded biocompatible, physically stable, and non-irritating mesoporous silica nanoparticles (EN-TA-loaded MSNs) were prepared and optimized by using a central composite rotatable design (CCRD) for providing better therapeutic efficacy against commonly prevailed resistant fungal infections. These drugs loaded MSNs can significantly overcome the deficiencies and problems like short duration of action, requirement of frequent administration, erythema, and burning sensation and irritation associated with conventional drug delivery systems. The stability of optimized drugs loaded MSNs prepared with 100 gm of oil at pH 5.6 with a stirring time of 2 h was confirmed from a zeta potential value of -25 mV. The remarkable compatibility of formulation ingredients was depicted by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR) spectra while scanning electron microscopy (SEM) and size analysis represented a very fine size distribution of nanoparticles ranging from 450-600 nm. The CCRD clearly predicted that the optimized parameters of drugs loaded MSNs have better values of percentage yield (85%), EN release (68%), and TA release (70%). Compared to pure drugs, the decreased cytotoxicity of EN-TA-loaded MSNs was quite evident because they showed a cell survival rate of 90%, while in the case of pure drugs, the survival rate was 85%. During in vivo antifungal testing against Candida albicans performed on three different groups, each consisting of six rabbits, the EN-TA-loaded MSNs were relatively superior in eradicating the fungal infection as a single animal exhibited a positive culture test. Rapid recovery of fungal infection and a better therapeutic effect of EN-TA-loaded MSN were quite evident in wound healing and histopathology studies. Likewise, on the 14th day, a larger inhibitory zone was measured for optimized nanoparticles (15.90 mm) compared to the suspension of pure drugs (13.90 mm). In skin irritation studies, MSNs did not show a grade of erythema compared to pure drugs, which showed a four-fold grade of erythema. As a result, MSNs loaded with combination therapy seem to have the potential of improving patient compliance and tolerability by providing enhanced synergistic antifungal effectiveness at a reduced dose with accelerated wound healing and reduced toxicity of therapeutics.

Application of Green Gold Nanoparticles in Cancer Therapy and Diagnosis.

Nanoparticles are currently used for cancer theranostics in the clinical field. Among nanoparticles, gold nanoparticles (AuNPs) attract much attention due to their usability and high performance in imaging techniques. The wide availability of biological precursors used in plant-based synthesized AuNPs allows for the development of large-scale production in a greener manner. Conventional cancer therapies, such as surgery and chemotherapy, have significant limitations and frequently fail to produce satisfying results. AuNPs have a prolonged circulation time, allow easy modification with ligands detected via cancer cell surface receptors, and increase uptake through receptor-mediated endocytosis. To exploit these unique features, studies have been carried out on the use of AuNPs as contrast agents for X-ray-based imaging techniques (i.e., computed tomography). As nanocarriers, AuNPs synthesized by nontoxic and biocompatible plants to deliver therapeutic biomolecules could be a significant stride forward in the effective treatment of various cancers. Fluorescent-plant-based markers, including AuNPs, fabricated using Medicago sativa, Olax Scandens, H. ambavilla, and H. lanceolatum, have been used in detecting cancers. Moreover, green synthesized AuNPs using various extracts have been applied for the treatment of different types of solid tumors. However, the cytotoxicity of AuNPs primarily depends on their size, surface reactivity, and surface area. In this review, the benefits of plant-based materials in cancer therapy are firstly explained. Then, considering the valuable position of AuNPs in medicine, the application of AuNPs in cancer therapy and detection is highlighted with an emphasis on limitations faced by the application of such NPs in drug delivery platforms.

Surfactant stabilized gold nanomaterials for environmental sensing applications - A review.

Surfactant stabilized Gold (Au) nanomaterials (NMs) have been documented extensively in recent years for numerous sensing applications in the academic literature. Despite the crucial role these surfactants play in the sensing applications, the comprehensive reviews that highlights the fundamentals associated with these assemblies and impact of these surfactants on the properties and sensing mechanisms are still quite scare. This review is an attempt in organizing the vast literature associated with this domain by providing critical insights into the fundamentals, preparation methodologies and sensing mechanisms of these surfactant stabilized Au NMs. For the simplification, the surfactants are divided into the typical and advanced surfactants and the Au NMs are classified into Au nanoparticles (NPs) and Au nanoclusters (NCs) depending upon the complexity in structure and size of the NMs respectively. The preparative methodologies are also elaborated for enhancing the understanding of the readers regarding such assemblies. The case studies regarding surfactant stabilized Au NMs were further divided into colorimetric sensors, surface plasmonic resonance (SPR) based sensors, luminescence-based sensors, and electrochemical/electrical sensors depending upon the property utilized by the sensor for the sensing of an analyte. Future perspectives are also discussed in detail for the researchers looking for further progress in that particular research domain.

Heating effect on quality characteristics of mixed canola cooking oils.

BACKGROUND: The subcontinent is famous for its variety of seasonal foods cooked in vegetable seed cooking oils at elevated heating. Oils are often of poor quality that effect to consumer health. The work, therefore, planned to examine the effects of heat on the quality of mixed canola cooking oils (MCCOs). MCCOs were analyzed by preparing volatile fatty acid methyl esters (FAMEs) and for physiochemical properties. RESULTS: A major change was observed in the FAs composition of various MCCOs as coded K-1 to K-5. MCCOs were found rich in unsaturated 9-octadecanoic acid (oleic acid C18:1) and 9, 12-octadecadienoic acid (linoleic acid C18:2) along saturated octadecanoic acid (stearic acid C18:0). Results reveals that canola oil samples are mixed in the range of 4-30% with other vegetable oils and animal fats. The quality of canola cooking oils further reduced after heating to 100 °C, 200 °C and 350 °C, respectively. Quality parameters of MCCOs were significantly altered after heating and found as color (510-520 nm to 570-600 nm), mass 220-237 g to 210-225 g, volume 250 mL to 239 mL, pH (6.76-6.89), specific gravity (0.87-0.92), refractive index (1.471-1.475), saponification value (SV) (0.7-2.5), un-saponifiable matter (2.4-9.8%) and acid value (AV) (1.20-5.0 mg KOH). CONCLUSION: Heating of oils at elevated temperature have shown a significant effect on pH, specific gravity and un-saponifiable matter (p-value < 0.05). Large changes in the physicochemical parameters and FAs composition help to develop a conclusion that cooking at high temperatures affects the quality of mixed canola cooking oils.

Multivariate Investigation of Toxic and Essential Metals in the Serum from Various Types and Stages of Colorectal Cancer Patients.

Colorectal cancer (CRC) is currently one of the most frequent malignant neoplasms, ranking 3rd in incidence and 2nd in mortality both in the USA and across the world. The pathogenesis of CRC is a complex interaction between genetic susceptibility and environmental factors such as exposure to metals. Therefore, the present study was intended to assess the imbalances in the concentrations of selected essential/toxic elements (Pb, Cr, Fe, Zn, As, Cd, Cu, Se, Ni, and Hg) in the serum of newly diagnosed colorectal carcinoma patients (n = 165) in comparison with counterpart controls (n = 151) by atomic absorption spectrometry after wet-acid digestion method. Serum carcinoembryonic antigen (CEA) of the CRC patients was determined using immunoradiometric method. Body mass index (BMI) which is an established risk factor for CRC was also calculated for patients and healthy controls. Conversely, average Ni (2.721 µg/g), Cd (0.563 µg/g), As (0.539 µg/g), and Pb (1.273 µg/g) levels were significantly elevated in the serum of CRC patients compared to the healthy donors, while the average Se (7.052 µg/g), Fe (15.67 µg/g), Cu (2.033 µg/g), and Zn (8.059 µg/g) concentrations were elevated in controls. The correlation coefficients between the elements in the cancerous patients demonstrated significantly dissimilar communal relationships compared with the healthy subjects. Significant differences in the elemental levels were also showed for CRC types (primary colorectal lymphoma, gastrointestinal stromal tumor, and adenocarcinoma) and CRC stages (stage-I, stage-II, stage-III, and stage-IV) among the patients. Majority of the elements demonstrated perceptible disparities in their levels based on dietary, habitat, gender, and smoking habits of the malignant patients and healthy subjects. Multivariate methods revealed noticeably divergent apportionment among the toxic/essential elements in the cancerous patients than the healthy counterparts. Overall, the study showed significantly divergent distribution and associations of the essential and toxic elemental levels in the serum of the CRC patients in comparison with the healthy donors.

New organosulfur metallic compounds as potent drugs: synthesis, molecular modeling, spectral, antimicrobial, drug likeness and DFT analysis.

During the present investigation, two new sulfonamide-based Schiff base ligands, 4-{[(2-hydroxy-3-methoxyphenyl)methylidene]amino}-N-(1,3-thiazol-2-yl)benzene-1-sulfonamide (L1) and 4-{[1-(2-hydroxyphenyl)ethylidene]amino}-N-(1,3-thiazol-2-yl)benzene-1-sulfonamide (L2), have been synthesized and coordinated with the transition metals (V, Fe, Co, Ni, Cu and Zn). The ligands were characterized by their physical (color, melting point, yield and solubility), spectral (UV-Vis, FT-IR, LC-MS, 1H NMR and 13C NMR) and elemental data. The structures of the metal complexes (1)-(12) were evaluated through their physical (magnetic and conductance), spectral (UV-Vis, FT-IR and LC-MS) and elemental data. The molecular geometries of ligands and their selected metal complexes were optimized at their ground state energies by B3LYP level of density functional theory (DFT) utilizing 6-311+G (d, p) and LanL2DZ basis set. The first principle study has been discussed for the electronic properties, the molecular electrostatic possibilities as well as the quantum chemical identifiers. An obvious transition of intramolecular charge had been ascertained from the occupied to the unoccupied molecular orbitals. The UV-Vis analysis was performed through time-dependent density functional theory (TD-DFT) by CAM-B3LYP/6-311+G (d, p) function. The in vitro antimicrobial activity was studied against two fungal (Aspergillus niger and Aspergillus flavus) and four bacterial (Staphylococcus aureus, Klebsiela pneumoniae, Escherichia coli and Bacillus subtilis) species. The antioxidant activity was executed as antiradical DPPH scavenging activity (%), total iron reducing power (%) and total phenolic contents (mg GAE g-1). Additionally, enzyme inhibition activity was done against four enzymes (Protease, α-Amylase, Acetylcholinesterase and Butyrylcholinesterase). All the synthetic products exhibited significant bioactivity which were found to enhance upon chelation due to phenomenon of charge transfer from metal to ligand.

Green photosensitisers for the degradation of selected pesticides of high risk in most susceptible food: A safer approach.

Pesticides are the leading defence against pests, but their unsafe use reciprocates the pesticide residues in highly susceptible food and is becoming a serious risk for human health. In this study, mint extract and riboflavin were tested as photosensitisers in combination with light irradiation of different frequencies, employed for various time intervals to improve the photo-degradation of deltamethrin (DM) and lambda cyhalothrin (λ-CHT) in cauliflower. Different source of light was studied, either in ultraviolet range (UV-C, 254 nm or UV-A, 320-380 nm) or sunlight simulator (> 380-800 nm). The degradation of the pesticides varied depending on the type of photosensitiser and light source. Photo-degradation of the DM and λ-CHT was enhanced by applying the mint extracts and riboflavin and a more significant degradation was achieved with UV-C than with either UV-A or sunlight, reaching a maximum decrement of the concentration by 67-76%. The light treatments did not significantly affect the in-vitro antioxidant activity of the natural antioxidants in cauliflower. A calculated dietary risk assessment revealed that obvious dietary health hazards of DM and λ-CHT pesticides when sprayed on cauliflower for pest control. The use of green chemical photosensitisers (mint extract and riboflavin) in combination with UV light irradiation represents a novel, sustainable, and safe approach to pesticide reduction in produce.

Pharmaco-Technical Evaluation of Statistically Formulated and Optimized Dual Drug-Loaded Silica Nanoparticles for Improved Antifungal Efficacy and Wound Healing.

The current research aimed at designing mesoporous silica nanoparticles (MSNs) for a controlled coadministration of salicylic acid (SA) and ketoconazole (KCZ) to effectively treat highly resistant fungal infections. The sol-gel method was used to formulate MSNs, which were further optimized using central composite rotatable design (CCRD) by investigating mathematical impact of independent formulation variables such as pH, stirring time, and stirring speed on dependent variables entrapment efficiency (EE) and drug release. The selected optimized MSNs and pure drugs were subjected to comparative in vitro/in vivo antifungal studies, skin irritation, cytotoxicity, and histopathological evaluations. The obtained negatively charged (-23.1), free flowing spherical, highly porous structured MSNs having a size distribution of 300-500 nm were suggestive of high storage stability and improved cell proliferation due to enhanced oxygen supply to cells. The physico-chemical evaluation of SA/KCZ-loaded MSNs performed through powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA) indicates absolute lack of any interaction between formulation components and successful encapsulation of both drugs in MSNs. The EESA, EEKCZ, SA release, and KCZ release varied significantly from 34 to 89%, 36 to 85%, 39 to 88%, and 43 to 90%, respectively, indicating the quadratic impact of formulation variables on obtained MSNs. For MSNs, the skin tolerability and cell viability percentage rate were also having an extraordinary advantage over suspension of pure drugs. The optimized SA/KCZ-loaded MSNs demonstrated comparatively enhanced in vitro/in vivo antifungal activities and rapid wound healing efficacy in histopathological evaluation without any skin irritation impact, suggesting the MSNs potential for the simultaneous codelivery of antifungal and keratolyic agents in sustained release fashion.

Assessment of SnFe2O4 Nanoparticles for Potential Application in Theranostics: Synthesis, Characterization, In Vitro, and In Vivo Toxicity.

In this research, tin ferrite (SnFe2O4) NPs were synthesized via hydrothermal route using ferric chloride and tin chloride as precursors and were then characterized in terms of morphology and structure using Fourier-transform infrared spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-Vis), X-ray power diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) method. The obtained UV-Vis spectra was used to measure band gap energy of as-prepared SnFe2O4 NPs. XRD confirmed the spinel structure of NPs, while SEM and TEM analyses disclosed the size of NPs in the range of 15-50 nm and revealed the spherical shape of NPs. Moreover, energy dispersive X-ray spectroscopy (EDS) and BET analysis was carried out to estimate elemental composition and specific surface area, respectively. In vitro cytotoxicity of the synthesized NPs were studied on normal (HUVEC, HEK293) and cancerous (A549) human cell lines. HUVEC cells were resistant to SnFe2O4 NPs; while a significant decrease in the viability of HEK293 cells was observed when treated with higher concentrations of SnFe2O4 NPs. Furthermore, SnFe2O4 NPs induced dramatic cytotoxicity against A549 cells. For in vivo study, rats received SnFe2O4 NPs at dosages of 0, 0.1, 1, and 10 mg/kg. The 10 mg/kg dose increased serum blood urea nitrogen and creatinine compared to the controls (P < 0.05). The pathology showed necrosis in the liver, heart, and lungs, and the greatest damages were related to the kidneys. Overall, the in vivo and in vitro experiments showed that SnFe2O4 NPs at high doses had toxic effects on lung, liver and kidney cells without inducing toxicity to HUVECs. Further studies are warranted to fully elucidate the side effects of SnFe2O4 NPs for their application in theranostics.

Effective Adsorptive Removal of Methylene Blue from Water by Didodecyldimethylammonium Bromide-Modified Brown Clay.

In the present investigation, brown clay (BC) was modified with didodecyldimethylammonium bromide (DDAB) to produce a sorbent (DDAB-BC), which was characterized and applied for sorption of methylene blue (MB) from aqueous media. BC was functionalized using DDAB by cation exchange of the DDAB moiety with positive ions existing inside the interlayer spaces of the BC. X-ray diffraction (XRD) studies confirmed that the d-spacing of DDAB-BC became wider (3.39 Å) than that of BC (3.33 Å). Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were exploited to explore the functional groups and morphological structure of sorbents, respectively. The Brunauer-Emmett-Teller (BET) surface area, pore volume, and pore diameter of DDAB-BC were determined as 124.6841 m2/g, 0.316780 cm3/g, and 8.75102 nm, respectively. Batch sorption investigations were carried out to determine the optimum experimental conditions, using the one-factor one-time procedure. The sorption of MB on DDAB-BC strongly obeyed the Langmuir isotherm and agreed well with pseudo-second-order kinetics. Sorption of MB onto DDAB-BC showed maximum efficiency (∼98%) and maximum sorption capacity (∼164 mg/g) at optimal values of pertinent factors: dye concentration (100 mg/L), pH (7), and temperature (55 °C). Sorption isothermal studies predicted that removal of MB on DDAB-BC follows multilayer sorption at higher MB dye concentrations and monolayer sorption at lower MB dye concentrations.

Application of Fusarium sp. immobilized on multi-walled carbon nanotubes for solid-phase extraction and trace analysis of heavy metal cations.

In the present work, for the first time, the filamentous fungus Fusarium sp. was utilized for devising a novel method for pre-concentration and determination of trace amounts of Pb(II), Cu(II), Cd(II), and Zn(II) ions, using a mini-column packed with Fusarium-coated multi-walled carbon nanotubes and inductively coupled plasma-optical emission spectrometry. Optimal analytical conditions including pH, ionic strength, elution solution, sample and eluent flow rates, and sample volume were determined. The detection limits were 0.39, 0.060, 0.021, and 0.025 ng mL-1 for Pb(II), Cu(II), Cd(II), and Zn(II) cations, respectively. This new method demonstrated a high performance for the analytes, and their adsorption was not affected by the different co-existing ions. The present procedure was validated by the analysis of standard reference materials, since the obtained data were in close agreement with reference values. Finally, this new procedure was successfully applied to analysis of heavy metal cations in natural food and water samples.

Turn-on fluorescent glutathione detection based on lucigenin and MnO2 nanosheets.

In this work, a glutathione (GSH) sensing nano-platform using lucigenin as a fluorescent probe in the presence of MnO2 nanosheets was reported for the first time. Unlike the earlier fluorescent detection systems based on MnO2 nanosheets, which depend on Förster resonance energy transfer (FRET) or the dynamic quenching effect (DQE), the mechanism of the quenching process of MnO2 nanosheets on lucigenin fluorescence was attributed mainly to a static quenching effect (SQE) with a minor contribution of the inner filter effect (IFE). A double exponential fluorescence decay of lucigenin was obtained in various MnO2 nanosheet concentrations as a result of their SQE and IFE. Based on this phenomenon and taking advantage of the redox reaction between GSH and MnO2 nanosheets, we have developed a switch-on sensitive fluorescent method for GSH via the recovery of the MnO2 nanosheet-quenched fluorescence of lucigenin. A good linearity range of 1.0-150.0 µM with a low limit of detection (S/N = 3) of 180.0 nM was achieved, revealing the higher sensitivity for GSH determination in comparison with the previously reported MnO2 nanosheet-based turn-on fluorescent methods. The developed fluorescent nano-platform exhibits excellent selectivity with successful application for GSH detection in human serum plasma, indicating its good practicability for GSH sensing in biological and clinical applications.

Highly sensitive and selective non-enzymatic glucose detection based on indigo carmine/hemin/H2O2 chemiluminescence.

A new chemiluminescence (CL) system, indigo carmine/glucose/hemin/H2O2, has been found and developed for non-enzymatic detection of indigo carmine (IC) and glucose. The CL response increases linearly with IC concentrations from 3.2 µM to 10 mM and glucose concentrations from 0.06 µM to 3.5 mM. The detection limits are 1.45 µM and 15.0 nM for IC and glucose, respectively. This method allows the determination of glucose in blood and urine after simple dilution. The recoveries for the determination of glucose are between 98.5% and 101.0% in blood and between 98.5% and 101.3% in urine. This method shows good sensitivity, selectivity, simplicity, and is low cost, suggesting its promising broad applications.

Statistical Assessment of Toxic and Essential Metals in the Serum of Female Patients with Lung Carcinoma from Pakistan.

Lung cancer (LC) is the number one cancer killer of women both in the USA and around the world. Besides cigarette smoking, an important feature in the etiology of LC is its strong association with exposure of toxic metals. The primary objective of the present investigation was to assess the concentrations of toxic/essential elements (Ni, Ca, Se, Zn, Co, K, Cr, As, Cu, Na, Fe, Hg, Cd, Mg, Mn, and Pb) in the serum samples of LC female patients with female controls by atomic absorption spectrometry after wet-acid digestion procedure. Carcinoembryonic antigen (CEA) was also measured in the serum of the patients using immunoradiometric method. Comparative appraisal of the data revealed that concentrations of Cr, Mg, Cd, Pb, Hg, As, and Ni were noted to be high significantly in serum of LC female patients, while the average Fe, Co, Mn, Na, K, Zn, Ca, and Se were observed at higher levels in female controls (p < 0.05). The correlation study revealed significantly different mutual associations among the elements in the both donor groups. Markedly, variations in the elemental levels were also noted for different types (non-small cell lung cancer and small cell lung cancer) and stages (I, II, III, & IV) of LC patients. Multivariate analyses showed substantially diverse apportionment of the metals in the female patients and female controls. Hence, present findings suggest that the toxic and essential metals accumulated in the body may pose a high risk for LC progression in Pakistani females.

Determination of Concentrated Hydrogen Peroxide Free from Oxygen Interference at Stainless Steel Electrode.

H2O2 is frequently used at high concentrations in various applications. It is very challenging to detect high concentrations of H2O2 and to eliminate oxygen interference for H2O2 detection through electrochemical reduction. In the present investigation, the electrochemistry of H2O2 at stainless steel electrode has been carried out for the first time. A cathodic peak for H2O2 reduction was observed at about -0.40 V, and no cathodic peak for dissolved oxygen reduction was observed on type 304 stainless steel electrode. Amperometric determination of H2O2 on type 304 stainless steel electrode displayed a linear range from 0.05 up to 733 mM with a detection limit of 0.02 mM (S/N = 3) and a sensitivity of 16.7 µA mM-1 cm-2. The type 304 stainless steel electrode not only shows much higher upper limit than other reported electrodes for the detection of concentrated H2O2 but also is free from oxygen interference, which is of great importance for practical applications. This method could detect H2O2 in wound wash and lake water with excellent recoveries. Moreover, we successfully applied the stainless steel electrode to determine glucose using glucose oxidase to catalyze the oxidation of glucose to generate hydrogen peroxide. The linear range for glucose is between 0.5 and 25 mM, which covers clinically important blood glucose concentrations well.