Poly(vinyl pyrrolidone)-mediated synthesis of silver nanowires decorated with silver nanospheres and their antimicrobial activity

Pathogenic infectious diseases, like bacterial infections, are one of the most prevalent types of diseases all over the world. Although antibiotics are commonly used and widely available drugs for the treatment of bacterial infections, bacteria show multiple drug resistance, have a tendency to get genetically mutated and become resistant to commonly employed antibiotic drugs. This makes the invention of novel drugs essential. One of the possible approaches is the use of nanomaterials for this purpose. The present study attempts to synthesize silver nanospheres and silver nanowires and compare their antibacterial activity. Silver nanospheres were synthesized by chemical reduction of silver nitrate in the presence of a suitable stabilizer. For the synthesis of silver nanowires, polyol method was employed. Silver nanowires neatly decorated with silver nanospheres were obtained. The antibacterial activity was estimated by separately determining the minimum inhibition concentration of the two nanostructures on Gram-positive bacteria Bacillus subtilis and Gram-negative bacteria Escherichia coli cultured on Luria Bertani agar media. The comparison shows that the antibacterial activity of silver nanospheres is better than that of silver nanowires which is attributed to its higher surface area and the difference in uptake mechanism by the bacterial cells.