Abstract
Natural red purple dye, Betanin, was extracted from the beetroot, purified by aqueous two- phase extraction and gel permeation column chromatography, and used as a reducing agent for the synthesis of silver-betanin core-shell triangular nanodisks for the first time. Spectroscopic data show that the nanoparticle structure is core@shell like with Ag as core and betanin as shell. Langmuir monolayer model (q(m)= 32.4 mg/g, R-L= 0.99 and R-2= 0.997) was the best fit adsorption isotherm for the dye removal. Adsorption kinetics is well explained by pseudo-second-order equation. Gibbs free energy (Delta G(0)= -2.59 kJ mol(-1)), enthalpy (Delta H-0= 18.05 kJ mol(-1)), and entropy (Delta S-0= 68.92 J/K/mol) were calculated and discussed. The antibacterial activity of betanin-AgNPs were determined against Escherichia coli MTCC-450 (E. coli) and Staphylococcus aureus MTCC-3160 (S. aureus) bacteria.