Thiomalic acid/ferric chloride-based deep eutectic solvent for microextraction of chromium in natural water samples prior to FAAS analysis

Deep eutectic solvents have become interested green materials for microextraction applications. In this study, a novel deep eutectic solvent have been formed by combination of thiomalic acid and ferric chloride in ethylene glycol medium, which then used for liquid-liquid microextraction of trace chromium from water samples. The microextraction process is donated the name of deep eutectic solvent-liquid liquid microextraction (DES-LLME). The microextraction procedure was optimised by evaluating the effect of pH, amount of deep eutectic solvent and sample volume. The optimum recoveries for chromium were achieved at pH 7.0, 200 mu L of deep eutectic solvents, and sample volume up to 40 mL, with limits of detection and quantification of 1.18 mu g center dot L-1 and 3.54 mu g center dot L-1 respectively. By validating the DES-LLME with TMDA-53.3 fortified water reference materials, the chromium recovery was 99%

Electrocatalytic evaluation of graphene oxide warped tetragonal t-lanthanum vanadate (GO@LaVO4) nanocomposites for the voltammetric detection of antifungal and antiprotozoal drug (clioquinol)

Metastable and rarely reported GO warped tetragonal phase t-lanthanum vanadate nanocomposites (GO@LaVO4-NCs) are reported for the sensitive electrochemical determination of antifungal drug Clioquinol (CQ). The hydrothermal method was adopted for synthesis of GO@LaVO4-NCs. The electrochemical performance of CQ was examined using cyclic voltammetry (CV) and differential plus voltammetry (DPV) at GO@LaVO4-NCs modified glassy carbon electrode (GCE). The electrocatalytic oxidation of CQ at the GO@LaVO4-NCs/GCE shows the highest anodic peak current at a potential of +0.51 V vs. Ag/AgCl. The proposed sensor provides excellent sensitivity of 4.1894 mu A mu M-1 cm(-2), a very low detection limit (LOD) of 2.44 nM, and a wide range of 25 nM to 438.52 mu M towards CQ detection. Finally, the detection of CQ in biological media was successfully done using the GO@LaVO4-NCs/GCE and possesses recoveries of 94.67-98.0%

Pharmacological evaluation and binding behavior of 4,4′-diamino-2,2′-stilbene disulfonic acid with metal ions using spectroscopic techniques

Industrial and human activities contribute significantly to the environmental contamination of heavy metal ions (HMIs), which have detrimental effects on aquatic life, plants, and animals, causing major toxicological problems. The commercially available 4,4′-diamino-2,2′-stilbenedisulfonic acid (DSD) has been playing a vital role in the detection of heavy metal ions and has significantly inhibited a variety of cancer cells in numerous field of modern science. The current investigation aimed to ensure the detection of heavy metals ions from the environment and fluorescence imaging of DSD in the treatment of cancer cells. Fluorescence and UV–Visible spectroscopic analysis was performed to sense the selective behavior of the probe DSD with several heavy metal ions, including Fe2+, K1+, Co2+, Ni2+, Zn2+, Cd2+, Pb2+, Mn2+, Sn2+, and Cr3+. Furthermore, DSD was subjected to examine enzyme inhibition such as anti-Alzheimer, anti-inflammatory, antioxidant, anticancer, and antimicrobial activities in search of multifaceted drugs. Test compounds have demonstrated dose-dependent responses in the in-vitro enzyme inhibition assays for acetylcholinesterase (AChE), butyrylcholinesterase (BChE), cyclooxygenase (COX), and lipoxygenase (LOX), as well as antioxidant [DPPH = 2,2-diphenyl-1-picrylhydrazyl and ABTS = 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid]. The DSD were shown to be more effective than the conventional medication galantamine in inhibiting acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), with an IC50 value of 12.18 and 20.87 μM, which is equivalent to the standard drug. The results obtained has revealed that DSD has the potential to become an effective sensor for the detection of Sn2+ ions over competing metal ions due to the inhibition of photo-induced electron transfer pathway (PET). The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide tetrazolium) test, demonstrated that DSD had strong anticancer effects against the brain cancer cell line NIH/3T3, HeLa and MCF-7 with an IC50 value of 32.59, 15.31 and 96.46 μM respectively. The antimicrobial testing has shown that DSD outperforms the standard drug cefixime against Candida albicans and Pseudomonas aeruginosa, respectively. This study makes a substantial contribution to the ongoing search for efficient treatments for breast cancer

Highly selective simultaneous electrochemical detection of trace level of heavy metals in water samples based on the single-crystalline Co3O4 nanocubes modified electrode

© 2021 Elsevier B.V.This study discussed the simultaneous electrochemical detection of highly toxic Pb2+, Cu2+, Hg2+ heavy metals by the Co3O4 modified electrode. The Co3O4 nanocubes (Co3O4-NC) are prepared by the facile hydrothermal synthesis route which produces highly crystalline particles without an annealing process. The structural properties are characterized by XRD, Raman, XPS, FESEM, and HRTEM analysis. The SAED pattern endorses the single-crystalline nature of Co3O4-NC. The prepared material was subjected to detect the heavy metals electrochemically via DPV techniques. The Co3O4-NC/SPCE revealed good electroanalytical activity towards both individual and simultaneous detection of heavy metals. The developed heavy metal sensor exhibited good sensitivity (16.73 ± 0.8 µA µM−1 cm−2 for Pb2+, 11.46 ± 0.5 µA µM−1 cm−2 for Cu2+, and 16.86 ± 0.7 µA µM−1 cm−2 for Hg2+) and LOD (4.1 ± 0.2, 0.9 ± 0.04, 0.1 ± 0.005 nM for Pb2+, Cu2+, Hg2+, respectively) in the simultaneous detection. Moreover, the Co3O4-NC/SPCE exhibited high selectivity with the other potential interfering metal ions and nitro compounds in tap water and pond water samples. Additionally, the Co3O4-NC/SPCE reveals good recoveries of about 100–101.5% for tap water and 97–101% for pond water samples. Hence, our proposed Co3O4-NC/SPCE is a good electrode material for the determination of toxic heavy metal pollutants in real-time monitoring sensor devices