Evaluation of Gerbera jamesonii Derived Silver Nanoparticles for Photocatalysis, Antibacterial Activity and Detection of Melamine Adulteration in Milk

Nanotechnology plays a crucial role in today’s world in fields of food technology and textile. The present study focuses on green synthesis of silver nanoparticles using 5 petal extracts of Gerbera jamesonii and assessing its photocatalytic and antibacterial activity. The petal extracts were subjected to 30-min incubation at 90 ◦C for AgNP synthesis. Qualitative and quantitative analysis of antioxidants were carried out and results were statistically analysed in order to determine the highest incorporation of antioxidants in AgNP synthesis. The shape and size of synthesised AgNP were analysed using SEM, which showed spherical AgNPs with a diameter of 50–60 nm. Photocatalytic activity with Malachite Green (MG) in the presence of NaBH4 confirmed a higher rate constant with AgNP diluted at 267 ppm. Antibacterial activity tested using well diffusion technique against Escherichia coli showed a higher growth inhibition in red (GerR), white (GerW) and yellow (GerY) petal extracts and Staphylococcus aureus showed a higher growth inhibition in AgNPs synthesised with pink (GerP) and yellow (GerY) petal extracts. Melamine adulteration in Milk was assessed using raw milk and 2 mM melamine spiked milk samples. A clear colour change was observed, and absorption peak was visible at 500–540 nm confirming the ability to detect melamine using AgNPs synthesised using GerP extracts. The results therefore suggests that green synthesised AgNPs can be utilised for various applications which will play a crucial role in quality assurance purposes in the food technology and textile industries.