Cadmium Sulfide Nanoparticles Decorated with Au Quantum Dots as Ultrasensitive Photoelectrochemical Sensor for Selective Detection of Copper(II) Ions

Anomalous ingestion of copper has significant adverse effects and shows acute toxicity in living organisms. Recently, photoelectrochemical (PEC) method has attracted much attention as a platform for a Cu²⁺ ion sensor because of its high sensitivity, selectivity, low-cost, and accurate selection compared to other conventional methods. In this work, stepwise hydrothermal and <i>in situ</i> chemical approaches for synthesizing cadmium sulfide nanoparticles (CdS NPs) for decorating gold quantum dots (Au QDs) are presented, along with notable PEC performance. The amount of Au QDs loaded on the CdS NPs had a significant influence on the PEC performance. CdS NPs-Au QDs-2 with 1.0 mmol % Au QDs demonstrated an exceptional photocurrent density of 350.6 μA cm^–2, which was 3.7-, 2.2-, and 2.0-fold higher than those of CdS NPs, CdS NPs-Au QDs-1 (0.75 mmol %), and CdS NPs-Au QDs-3 (1.25 mmol %), respectively. Femtosecond transient absorption dynamics of the ground state recovery showed a buildup time of 243 fs for Au and 268 fs for CdS, which were assigned to cooling of the photoexcited electrons. For CdS NPs-Au QDs, the transient spectrum was dominated by a signal from CdS with no contribution from Au. The fast buildup dynamic was absent in CdS-Au, indicating a rapid transfer of the photoexcited electrons from CdS to Au before cooling down. Unquestionably, the CdS NPs-Au QDs-2 photoelectrode response upon Cu²⁺ detection showed the lowest limit of detection of 6.73 nM in a linear range of 0.5–120 nM. The selectivity of CdS NPs-Au QDs-2 toward Cu²⁺ ions in lake and tap water was also studied, which suggested that CdS NPs-Au QDs-2 is promising as a photoactive material for PEC-based environmental monitoring and analysis

Bioinspired Nanomaterials

Biological synthesis employing microorganisms, fungi or plants is an alternative method to produce nanoparticles in low-cost and eco-friendly ways. The book covers the synthesis of metal nanoparticles, metal oxide nanostructures and nanocomposite materials, as well as the stability and characterization of bioinspired nanomaterials. Applications include optical and electrochemical sensors, packaging, SERS and drug delivery processes.Используемые программы Adobe AcrobatБиологический синтез с использованием микроорганизмов, грибов или растений является альтернативным методом получения наночастиц недорогими и экологически чистыми способами. Книга посвящена синтезу наночастиц металлов, наноструктур из оксидов металлов и нанокомпозитных материалов, а также стабильности и характеристикам наноматериалов, вдохновленных биоинспирированием. Области применения включают оптические и электрохимические датчики, упаковку, SERS и процессы доставки лекарств

Bioinspired Nanomaterials for Energy and Environmental Applications

В книге представлены последние достижения в области синтеза наноматериалов с биоинспирированием и их применения в таких областях, как фотокатализ, электрокатализ и фотоэлектрокатализатор, суперконденсаторы и солнечные элементы. Конкретные темы включают фотокаталитическую дезинфекцию, разложение токсичных химических веществ, преобразование энергии и накопление энергии.Используемые программы Adobe AcrobatThe book presents recent advances in the synthesis of bioinspired nanomaterials and their applications in areas such as photocatalysis, electrocatalysis and photoelectrocatalysis, supercapacitors and solar cells. Specific topics include photocatalytic disinfection, degradation of toxic chemicals, energy conversion and energy storage

Antioxidant and free radical scavenging activities of common wild greens from Tiruvallur District of Tamil Nadu, India

156-163The antioxidant and radical scavenging activities of common wild greens used by the village people in Tiruvallur District, Tamil Nadu were evaluated. Among the plants studied, the methanol extract of Euphorbia hirta Linn. was found to be rich in polyphenol content and had a low IC50 value for DPPH (78.33 µg) and hydroxyl radical scavenging (662.62 µg). It showed high antioxidant activity. The methanol extract of Senna auriculata (Linn.) Roxb. syn. Cassia auriculata Linn. flowers and Eclipta prostrata Linn., leaves were also effective. The efficacies of the other plants were in the following order: Cardiospermum helicacabum Linn.var. luridum Blume > Boerhavia diffusa Linn. > Centella asiatica (Linn.) Urban > Cissus quadrangularis Linn. > Celosia argentea Linn. > Marsilea quadrifolia Linn. > Pisonia grandis R. Br. syn. P. alba Span. > Solanum trilobatum Linn. These plants have been traditionally used by villagers without any noticeable adverse effects. The present study has indicated that the isolation of some specific compounds responsible for these activities might help in several aspects of food chemistry

Additions To the Grass Flora of Tamil Nadu

Volume: 102Start Page: 362End Page: 36

Experimental and theoretical study on optimizing caxBa1-xSnO3 perovskite materials as photoanode of dye-sensitized solar cells

The various compositions of CaxBa1−xSnO3 perovskite materials were synthesized by hydrothermal method and they were fabricated as the photoanode of dye-sensitized solar cells (DSSC). Among them, Ca0.1Ba0.9SnO3 composition shows better efficiency with the JSC of 4.64 mA cm−2 and VOC of 0.726 V. The conduction band minimum (CBM) of Ca0.1Ba0.9SnO3 material is slightly lower than excited-state potential of N719 dye molecules. This provides high electron transfer from dye to this perovskite material after shining the light. The structural stability and electronic properties of these materials were studied by first principles density functional theory (DFT) calculations. Our study revealed that CBM is mainly distributed by Sn 5s states, which provides high electronic mobility. This mobility is not altered much even for substitution of small amount of Ca atoms into BaSnO3

Pharmacological evaluations of ethanol extract of Ficus benghalensis L. seeds for its antiulcer and antimicrobial efficacy

To evaluate the gastroprotective effect and antimicrobial efficacy of the seeds of Ficus benghalensis L. Acute oral toxicity study was performed according to the OECD test guidelines and the antiulcer assay was performed using ethanol-induced gastric ulcer model in albino rats. The antimicrobial activity and HPTLC analysis were also performed. The seed extract did not show any sign of toxicity at a dose of 4000 mg/kg body weight. Reductions in the ulcer index and gastric acid volume with increase in the pH of the gastric fluid in extract treated rats proved antiulcer activity. Increased levels of endogenous antioxidant enzymes superoxide dismutase and catalase with a decrease in lipid peroxidation in the extract treated animals demonstrated its antioxidant effect. The zone of inhibition was extremely great for all the tested microorganisms. HPTLC chromatogram showed a total of 9 peaks at different Rf values and peak area at 366 nm whereas seven peaks were observed at 254 nm. The number of peaks indicates the presence of constituents in the extract. Pre-treatment with F. benghalensis seed extract showed significant antiulcer activity that might be attributed to its antioxidant potential. F. benghalensis showed significant activity against bacteria and fungi. The extract containing phytoconstituents must have contributed to its antimicrobial activity