@ Vincent Slight typo in your reply. It's normally the diammine complex of silver nitrate (not nitride) that's preferred for Ag colloid preparation. See, for example:
September 2nd, 2015 Silver colloids and invisible ink
Silver sulfate is rarely used due to the probably of incorporation of sulfur into the system which can (for example) act as a catalyst poison. It's also harder to reduce.
@Shaista Ask your question by opening/starting a new one. It appears to have nothing to do with this posted question, so I suspect you'll not get any answers as people can't find your question.
There are several methods for synthesis of silver NPs such as chemical, physical and biological methods. In recent years, the development of efficient green chemistry methods for synthesis of metal nanoparticles has become a major focus of researchers. it include the synthesis of SNPs using plant extract and different types of microorganisms