Currently, biological methods compared with conventional chemical and physical methods, could be a preferable synthesis route due to environmentally friendly conditions, despite their lower speed of metal reduction, it does not require further stabilizing agents, because extracts themselves act as stabilizing and capping agents and the nano powders, prepared by biological methods, rendering a good antimicrobial activity. Rare earth (RE) doped lanthanum oxyfluorides (LaOF) have been widely used in high performance luminescent devices, magnets, catalysts and other functional materials based on the electronic, optical and chemical characteristics. Among the rare earth compounds, more attention has been paid to Dy3+, Sm3+ ions because of its potential practical applications in electro luminescent displays, plasma display panels, field emission mercury-free lamps etc. LaOF nano powders are uniform size and highly crystalline nature, due to its, identification of individuals in forensic field easily by using fingerprints.