No standard amount is there. Depending upon you.

Its a pretty simple and straightforward procedure. Please follow the procedure given in the paper attached below. You can also mix the plant extract and AgNO3 in different ranges from 1:1 to 1:20 for better results.

Sir Syed Salman Hashmi thank you for your answer. But what do you mean by 1:1? Example? 5mL extract is to 50mL of silver nitrate? Then if im going to make 1:2, then it would be 5mL extract is to 100mL silver nitrate? Please enligtened me...and how long would it take? Is there a standard time and temperature? Thank you...

Since we have done a lot of work on biosynthesis of AgNPs, we mostly start directly by taking a ratio we know for sure. 5ml extract with 50 ml AgNO3 means 1:10.

For starters, you should prepapre plant extract and AgNO3 solution as given in paper, after that mix them in different ratios 1:1(1ml extract + 1ml AgNO3), 1:2(1ml extract =2ml AgNO3), 1:5(1ml extract + 5ml AgNO3) and 1;10(1ml extract + 10 ml AgNO3). Check which ratio gives better results and then go on with that ratio for further experiments.

Silver nanoparticles biosynthesis is mostly achieved at room temp. with most widely reported temp being 25 degree Celsius however, it may vary depending upon the plant used.

As for time, there are no standards and it also vary depending upon the plant used for extract preparation. Synthesis may be seen within few minutes or may prolong for even a day or two.

Oh thank you so much for that helpful answer sir Syed Salman Hashmi, really it would help us begginers...how we can prepare silver nitrate solution? Are there a ready made silver nitrate solution?. That can be bought? Or we have to prepare it by ourselves?

Solution isn't available. You have to prepare it using Silver Nitrate salt. Silver Nitrate salt is readily soluble in water. 1mM Silver Nitrate solution usually does the job however higher concentrations can also be used.

No standard amount is there. Depending upon you.

You can chose by optimizing different reaction. see the attached article

Article Biosynthesis of silver nanoparticles: A colorimetric optical...

Dear Muhammad Ismail :

When you do synthesis of Silver Nanoparticles, did AgOH or Ag2O will be made at the same time?

As soon as the aqueous extract came into contact with silver nitrate solution, the change in color was observed.

The color become white or dark (if add NaOH to maintain a pH value of 10).

That made me confused.

Could you kindly give me some suggestions?

Thanks for your assistance.

Dear Thor Mars at the start Ag2O is formed but after addition more reducing agent it reduced to Ag(0). Use dilute concentration of NaOH and before addition, introduced capping agent to the silver nitrate solution. At the start you will get black color but after stirring it will converted into dark red. It will be better if you use hydrazine instead of NaOH.