DNA-binding, antioxidant, H2O2 sensing and photocatalytic properties of biogenic silver nanoparticles using Ageratum conyzoides L. leaf extract

Green nanotechnology is gaining widespread interest owing to the elimination of harmful reagents and offers a cost-effective synthesis of expected products. In the present study, silver nanoparticles (AgNPs) were synthesized from Ageratum conyzoides leaf extract (ACLE). UV-visible spectrophotometry showing a characteristic SPR peak at 443 nm verified the phytosynthesis of AC-AgNPs. The FTIR spectrum was examined to identify the efficient functional molecules responsible for the reduction of Ag+ to metallic silver (Ag-0). SEM, TEM and XRD illustrated the formation of crystalline and spherical NPs with a size range of 14-48 nm. EDX data showed the presence of elemental silver with an energy peak at 3 eV. CT-DNA interaction with AC-AgNPs was investigated and the UV absorption spectra revealed a bathochromic effect indicating groove binding. AC-AgNPs showed a strong antioxidant property in a concentration-dependent manner when analyzed by DPPH and ABTS radical scavenging assay. AC-AgNPs were investigated as a SPR-based H2O2 sensor, which can provide promising opportunities in medical and environmental fields to detect reactive oxygen species such as H2O2. The catalytic effectiveness of phytosynthesized NPs was also examined within 2 h of exposure for methylene blue degradation under sunlight. There is thus a reasonable potential application of green synthesized AC-AgNPs for the degradation of hazardous synthetic dyes.