Are Bentong ginger (Zingiber officinale) biosynthesized silver nanoparticles safe and effective? An optimization, characterization, and toxicity evaluation study

• Small size of nanoparticles provides larger surface area which is relative to the volume • Bentong ginger extract is utilised for green synthesis silver nanoparticles • Phytochemicals in ginger helps nanoparticles reduction and as antibacterial The biosynthesis of silver nanoparticles from ginger extract is particularly interesting due to the bioactive compounds present in ginger, which have antioxidant, antimicrobial, and anti-inflammatory properties. The study aims to optimize, characterize and evaluate toxicity value of the biosynthesized silver nanoparticles using Bentong ginger ( Zingiber officinale ) rhizome extract and commercialized ginger powder extract as reducing and capping agents. The synthesis was optimized regarding pH, silver nitrate concentration, and incubation time for better yield and stability. Additionally, biosynthesized silver nanoparticles were characterized using UV-vis spectrophotometer, X-ray diffractometer, Fourier-transform Infrared, and Transmission Electron Microscope analysis. Cytotoxicity test was done using brine shrimp lethality test to determine toxicity value. The result for both Bentong ginger rhizome extract and commercialized ginger powder extract indicated that the maximum absorption of biosynthesized silver nanoparticles was 450 nm, with the most optimum pH of 11, 1 mM of silver nitrate concentration, and incubation time of 24 hours. The nanoparticles were almost spherical, with an average particle size of 15.08 ± 6 nm. The analysis confirms the presence of phytochemicals in the ginger extract that aids in reducing silver ions into silver nanoparticles. Brine shrimp lethality assay showed the LC 50 for AgNPs was medium toxic at 838.31 µg/mL. This is the first report utilizing Bentong ginger in silver nanoparticle synthesis.