The biosynthesis of silver nanoparticles using Mangifera indica leaf extract as reducing agent was successfully carried out. The usual microscopic and spectroscopic techniques such as UV-vis., FTIR, XRD, EDX, and SEM were used to confirm the formation of nanoparticles. The silver nanoparticles absorb light at wavelength of approximately 425 nm as confirmed by UV- visible spectroscopy. Optical property showed a colour change from colourless solution of silver nitrate to yellowish brown after addition of the plant extract. The FTIR confirmed the possible biomolecule responsible for the reduction of the silver nitrate solution as belonging to the amide and ester group. Interrogation of Pt/AgNP electrode for ascorbic acid oxidation using cyclic voltammetry suggests that the silver nanoparticles can be a promising candidate as biosensor for ascorbic acid detection.