Impact of reducing and capping agents on carbohydrates for the growth of Ag and Cu nanostructures and their antibacterial activities
Rayees Ahmad Rathera, Ramandeep K. Sarwarab, Niranjan Dasb, Bonamali Pala,*
This study presents a viable green synthesis approach to produce Ag and Cu nanoparticles (MNPs) by using carbohydrates such as glucose, fructose, sucrose, and starch as reducing agents and describes their antimicrobial activities against Escherichia coli DH5α. Optical and diffused light scattering analyses showed the Ag NPs ranged from 20 to 75 nm and the Cu NPs varied from 20 to 160 nm, which supports the differences in their absorption bands (400–434 nm for Ag and 458–641 nm for Cu). The reducing sugars interacted differently with Ag+ and Cu2+ based on their size and hydrolysis by NaOH resulting in effective stabilization of Ag0 and Cu0 and variation in the bactericidal activities of the MNPs. The antibacterial effects of the MNPs were evaluated by measuring the inhibition zones using E. coli DH5α as a test organism. No growth was observed by restreaking different parts of the clearly inhibited zones into new culture plates indicating the bactericidal efficacy of the Ag and Cu MNPs. The Ag NPs were found to be more effective in terms of the size of their inhibition zones (1.21–1.82 cm) compared with those of the Cu NPs (0.0–1.2 cm). This study provides a promising basis for the formulation of a new generation of bactericidal agents.
Green synthesis; Ag and Cu nanoparticles; Carbohydrate reducing agents; Antibacterial activities