Xanthan gum-capped Chromia Nanoparticles (XG-CrNPs): A promising nanoprobe for the detection of heavy metal ions.

The present study reports on the selective and sensitive detection of metals using xanthan gum-capped chromia nanoparticles (XG-CrNPs). The nanoparticles were synthesized by the chemical reduction method using sodium borohydride and xanthan gum as the reducing and capping agents, respectively. The synthesis of XG-CrNPs was confirmed by the appearance of the two absorption peaks at 272 nm and 371 nm in the UV-visible region. The nanoparticles have been extensively characterized by FTIR, TEM-EDX, XRD, and TGA analyses. The well-dispersed XG-CrNPs exhibited a quasi-spherical structure with an average particle size of 3 nm. A significantly low amount (2 µg/L) of XG-CrNPs was used for selective and sensitive detection of heavy metal ions. It showed excellent metal detecting properties by quenching its band gap signal which was extraordinarily conspicuous for Co(II), Hg(II), and Cd(II) in comparison to other metal ions like Ag(I), Ba(II), Mg(II), Mn(II), Ni(II), and Zn(II). The limit of detection of Co(II), Cd(II), and Hg(II) with this nanoprobe was found to be 2.167 µM, 1.065 µM, and 0.601 µM respectively. The nanoparticles manifested higher shelf-life and can be reused up to three consecutive cycles where most of its activity was conserved even after being used. Thus, it may find use in metal sensor devices for the detection of hazardous metals.

Efficient sensing of saccharin through interference synthesis of gum ghatti capped silver nanoparticles.

The presence of saccharin (SH) could be efficiently sensed (in the concentration range of 5 × 10-5 M to 5 × 10-1 M) through the interference synthesis of gum ghatti (GG) capped silver nanoparticles (GGAgNps). The synthesis used sodium borohydride and gum ghatti (GG) as the reducing and capping agents respectively. The strong hydrogen-bonding recognition between GG and SH was responsible for the interference. The intensity of the SPR peak of GGAgNps was found linearly dependent on [SH]. The SH detection was further enhanced when combo capping comprising of GG and chitosan (Ch) (in 1:1 weight ratio) was used while the use of gum acacia (GA) in place of Ch (in combo) decreased the detection sensitivity. The combo polysaccharide solutions had non-Newtonian behaviour and shear thinning property like GG. The method was also applied for the successful detection of SH in commercially available real juice samples.

Carboxymethyl cellulose-rosin gum hybrid nanoparticles: An efficient drug carrier.

Adequate release of 5-ASA in colon is challenging as it easily permeates at the acidic pH of the upper gastrointestinal tract. Targeting delayed release of 5-ASA at acidic pH, Carboxymethyl cellulose-rosin gum hybrid nanoparticles (CRNP3) with an average size of 267nm have been crafted through nanoprecipitation method. CRNP3 was extensively characterized using Fourier Transform Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and particle size analysis based on dynamic light scattering. Colon specific targeted in-vitro release of 5­Aminosalicylic acid from CRNPs was monitored in simulated gastric (SGF) and intestinal (SIF) fluids. The release rate was very slow in first 2h in SGF, while in SIF, it was greater and 72% drug was released in a controlled manner during the time span of 12h in contrast to native carboxymethyl cellulose or rosin gum for which 100% release was accomplished within 5h or 8h respectively. The delayed release from CRNPs is attractive for enhancing the bioavailability of drug in colon. The drug release followed zero-order kinetics and non-Fickian diffusion mechanism.

Synthesis of Aloevera/Acrylonitrile based Nanoparticles for targeted drug delivery of 5-Aminosalicylic acid.

Aloevera (AV) polysaccharide/acrylonitrile (AN) nanoparticles (AVANp4 of ∼50nm size) have been crafted via free radical polymerization method using persulfate/ascorbic acid (KPS/AA) and methylenebisacrylamide (MBA) as the redox initiator and crosslinker respectively. AVANp4 was extensively characterized using FTIR, SEM, TEM, XRD, and Thermal analysis (TGA & DTG). Inclusion of AN in AV polysaccharide has been evidenced by nitrile stretching peak at 2244cm-1 in FTIR spectrum of AVANp4. Colon specific targeted in-vitro release of 5-Aminosalicylic acid from AVANp4 has been studied in pH 1.2 and pH 7.4 buffer solutions at 37°C. The controlled release was witnessed up to 48h for AVANp4 in contrast to AV for which the release exhausted within 7-8h in both the buffers. The delayed release of the drug from AVANp4 is attractive since it can allow the drug to reach colon rather than being released in the upper part of the gastrointestinal tract.

Grafting of vinyl acetate-ethylacrylate binary monomer mixture onto guar gum.

Present article reports on guar gum (GG) functionalization through graftcopolymerization of vinylacetate (VAC) and ethylacrylate (EA) from their binary mixtures. The potassium persulfate/ascorbic acid (KPS/AA) redox initiator system has been used for the binary grafting under the previously optimized conditions for VAC grafting at guar gum. The concentration of ascorbic acid (AA), persulfate (KPS), and grafting temperature were varied to optimize the binary grafting. A preliminary investigation revealed that the copolymer has excellent ability to capture Hg(II) from aqueous solution. It was observed that the optimum % grafting sample (CP3) was best at Hg(II) adsorption. CP3 and mercury loaded CP3 (CP3-Hg) have been extensively characterized using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Thermo gravimetric analysis (TGA) and a plausible mechanism for the grafting has been proposed.