Ultrafast transient absorption spectroscopic (UFTAS) and antibacterial efficacy studies of phytofabricated silver nanoparticles using Ocimum Sanctum leaf extract

The current ongoing problem related to the AgNPs (silver nanoparticles) nanomedicine's lifetime of charge carrier dynamics is a concern that needs to be investigated. The efficient method for the biosynthesis of AgNPs results in the spherical shape similar to 34 nm using Ocimum sanctum leaf (Oc. sanctum) extract for antibacterial activity, Z-scan for optoelectronic and lifetime through ultrafast spectroscopy. AgNPs in concentrations ranging from 5 to 20 mu g/ml exhibit antibacterial activity against the rice disease caused by Xanthomonas Oryzae bacteria compared to the commonly used antibiotic Amoxicillin. The antibacterial efficacy of AgNPs against rice pathogen (Xanthomonas Oryzae. Pv. oryzae) proves to be an effective remedy when the concentration of nanoparticles increases. The charge carrier dynamics of biosynthesized AgNPs, govern the electron transport using ultrafast femtosecond transient absorption (UFTAS) spectroscopy which regulates the efficacy of the AgNPs against the bacteria. UFTAS measurements of the AgNPs show that tri-exponential ultrafast dynamics are involved in the relaxation process. The slow decay lifetime found at 758 nm as 5.97 ns (nanosecond) with 16.9 % recombination, indicates the dependency and size of AgNPs, thus implying a long-term slow interaction between bacteria and AgNPs. Further, the third-order nonlinear optical absorbance of AgNPs was calculated as beta = 0.259 x 10(-12) cm/W in the presence of natural chemicals and investigated by applying Z-scan in an open aperture suitable for optoelectronic applications. These highlights the benefits of biosynthesized AgNPs as it shows specific studies of nonlinear and charge transfer dynamics, which is further related to antibacterial applications in nanomedicines.

Automated summary

The investigation of the lifetime of charge carrier dynamics in AgNPs nanomedicine is a current ongoing concern. Biosynthesis of AgNPs using Ocimum sanctum leaf extract results in spherical nanoparticles with a diameter of approximately 34 nm. AgNPs exhibit antibacterial activity against Xanthomonas Oryzae bacteria, the rice pathogen, and their charge carrier dynamics govern their efficacy against bacteria.