Green synthesis of silver nanoparticles (AgNPs) using plant extracts has emerged as a viable environment-friendly method. The aim of the study was to biosynthesize AgNPs using cauliflower (Brassica oleracea var. botrytis) waste extract and further test their potential applications in photocatalytic degradation of methylene blue (MB) dye and Hg 2+ biosensing. Optimum extract concentration, AgNO 3 concentration, pH and temperature required for biosynthesis of stable AgNPs were determined by UV-visible spectroscopy. FT-IR, XRD, SEM, TEM, SAED, XPS and BET analysis were performed for characterizing AgNPs. MB dye degradation using AgNPs was determined by analyzing the intensity of dye absorption maxima at 664 nm. Specificity and sensitivity of biosynthesized AgNPs for Hg 2+ ions were studied for assessing their biosensing abilities. Optimum conditions needed for biosynthesis of stable AgNPs were observed to be 3 ml extract, 0.5 mM AgNO 3 , pH 8.5 and microwave-assisted heating at 600 W for 5 min. FT-IR analysis showed that the extract contained necessary functional groups that facilitated biosynthesis of AgNPs. XRD, SEM, TEM, SAED, XPS results confirmed the formation of AgNPs. BET analysis showed that AgNPs had an average size of 35.08 nm and surface area of 19.22 m 2 /g. Maximum MB dye degradation percentage of 97.57% was obtained at 150 min without any significant silver leaching thereby, signifying notable photocatalytic property of AgNPs. Biosensing studies showed that AgNPs were specifically able to detect up to 0.1 mg/l Hg 2+ ions. In summary, cauliflower waste served as a useful source of reducing agents for biosynthesizing AgNPs with promising environmental applications.

Background: Hydrochloric acid (pH 1.5-3.5) being the major component of gastric acid is produced by parietal cells of stomach. Its secretion is a complex and relatively energetically expensive process. The preservation of acidity of stomach is evidently important because of its implications in peptic and duodenal ulceration.Methods: In the present study, we attempted to compare the activity of 13 (F1-F13) antacid formulations (5-liquid, 4- quick releases and 4- tablets) by using acid-base neutralization studies. Preliminary antacid test (PAT) was performed to define whether the given formulation falls under the category of antacid wherein the pH of the antacid-acid (HCl) solution should be higher than pH of 3.5. The chosen antacids were further subjected to acid neutralizing capacity (ANC) (reaction between the sample of antacid and amount of acid neutralized by the formulation) and acid neutralizing potential (ANP) which explains the time duration during which a given sample of antacid can maintain pH above 3.5).Results: Out of the 13 samples tested, two formulations of pastels (F6, F12) were rejected as per the standard protocol of classifying formulations as antacids after screening for PAT. Sample F5 was found to have the highest ANC. F7 also showed highest ANC among the tablets tested. Also, F13 showed better ANC and ANP as in comparison to other quick releases.Conclusions: Digene products (F5, F7, and F13) showed better antacid properties. This data would provide insights into development of drug, comparison between antacids depending on their chemical formulation and determination of dosage to avoid plausible side effects.

Palladium nanoparticles (PdNPs) were synthesised using a microwave technique using Gymnema sylvestre (GSE) leaf extract. PdNPs were tailored to different PdCl 2 and plant extract concentrations. Using XRD the crystalline existence of GSE-PdNPs has been established, confirming the formation of face-centered cubic structure. UV-Vis spectra of PdNPs confirmed the reduction of Pd 2+ to Pd 0. The FTIR spectra indicate the existence of functional groups which are responsible for nanoparticles reduction and progression. The SEM discloses quasi-sphere nanoparticles without agglomeration or aggregation which TEM confirms further. The reduction of Cr (VI) was performed with PdNPs (10 mg/L) and achieved a reduction of 96% within 30 min. In order to investigate the efficient reduction of chromium from Cr (VI) to Cr (III), different reaction system parameters have been optimised.

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