Abstract
The present study investigates the surface modification of AgNPs (synthesized by neem leaves) by benzalkonium chloride (BAC). It was observed that 22 x 10(9) CFU were formed at 0.25 mM AgNPs concentration. However, it was reduced to 14 x 10(9) CFU for BAC-coated AgNPs at similar experimental conditions. The enzymatic activity of beta-glucosidase was significantly enhanced from 0.0625 mM to 0.5 mM concentration of AgNPs, as well as BAC-AgNPs. However, there was no further change of activity beyond this concentration. ZOI of AgNPs and BAC-AgNPs was measured against E. coli, B. subtilis, P. aeruginosa, and S pneumoniae at 0.25 mM and 0.50 mM concentrations of these bioactive agents. ZOI was 3.45 cm and 3.56 cm for AgNPs and BAC-AgNPs at 0.25 mM of these bioactive agents, respectively, against E. coli. However, these values were 4.28 cm and 4.40 cm, respectively, against B. subtilis. ZOI was obtained at 3.36 cm and 3.47 cm, respectively, against P. aeruginosa under similar experimental concentrations. However, ZOI was achieved at 3.44 cm and 3.62 cm, respectively, against S. pneumonia, under similar experimental conditions. Hence, such research findings can be exploited for potential applications in numerous environmental and biomedical fields.