Biomedical subjects
Publications and source records attributed to Sujit Kumar Ghosh.
A solution phase UV-irradiation technique has been exploited to produce an AuSe nanoalloy through fusion of preformed Au (photoproduced) and Se (chemically prepared) in a micellar (TX-100) medium.
Evolution of exclusively spherical tiny gold nanoparticle aggregates is reported by UV photoactivation of aqueous HAuCl4 solution in cetyltrimethylammonium chloride micelles. In the photoactivation process, citrate is introduced for the first time to obtain aggregates of interacting particles with a tight size distribution. It is seen that the spectrum is substantially altered from the usual Au plasma resonance while the particles are present in the aggregate. Due to the interparticle interaction, the solution renders a blue color. Blue-pink color transformation of the gold sol has been observed in relation to the change in the interparticle distances without any change in the aspect ratio of the particles.
The interaction of 3,7-diamino-2,8-dimethyl-5-phenyl phenazinium chloride (Safranine T) with the aqueous as well as reverse micellar solution of a phospholipid 1,2-diacyl-sn-glycero-3-phosphocholine (Azolecithin), a major structural phospholipid in brain, comprising approx 15% of total lipid, primarily localized in grey matter have been studied by absorption and fluorescence spectroscopic studies. The results show the evidence of complex formation of the dye in the ground and in the excited state. The interaction of the dye with the lipid in reverse micellar state is more compared to that in liposomes. An attempt has been made to determine the polarity of the microenvironment of the dye in liposomes or reverse micelles from the spectral studies of the dye in different solvents of known polarity. The polarity functions of the phosphatidylcholine (PC) liposomes are slightly lower compared to that of PC reverse micelles.
Hardened paste of Portland cement (HPPC) has been used as a low-cost adsorbent for the removal of arsenic from water environment. Results from the batch experiments, conducted at an initial concentration of 0.2 ppm of arsenate, suggest arsenate removal up to 95%. Kinetic profiles were developed for various conditions. Effects of adsorbent dose, common ions such as Ca(2+), Mg(2+), Fe(3+), Fe(2+), Cl(-), SO(4)(2-), NO(3)(-), PO(4)(3-) and of pH were studied in detail. Adsorption isotherm studies revealed that the Freundlich isotherm was followed with a better correlation than the Langmuir isotherm. Arsenite could also be removed up to approximately 88% using the same material, HPPC. Finally, column studies were undertaken involving the new HPPC to check the suitability of the material for the removal of total arsenic content from water body. Kinetic experiments for the removal of arsenic by column studies revealed a film diffusion mechanism.
Portland cement has been used as a low-cost adsorbent for the removal of arsenic from the water environment. In the batch experiments conducted at an initial concentration of 0.2 ppm of arsenate, it was found that arsenate could be removed up to 95%. Kinetic profiles were developed for various conditions. Effect of adsorbent dose. effects of common ions such as Ca(2+), Mg(2+), Fe(3+)/Fe(2+), Cl(-), SO4(2-), NO3(-), PO4(3-), and the effect of pH was studied. Adsorption isotherm studies were performed and it was observed that the Freundlich isotherm was followed with a better correlation than the Langmuir isotherm. Arsenite could also be removed up to approximately 88% using the same material. A new detection method for arsenate/arsenite was developed for routine analysis of arsenic and used during the entire study.
The evolution of sphere- and rod-shaped superparamagnetic Ni--Pd and Ni--Pt nanoparticles by wet chemical methods is reported. It has been shown that increased CTAB (cetyltrimethylammonium bromide) concentration at room temperature promotes the formation of a higher proportion of rod-shaped nanomagnets over spherical particles. Temperature-dependent magnetic properties, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and electron dispersive X-ray (EDX) studies reveal the superparamagnetic behavior, size distribution, and percentage composition of the alloyed structures.