Green synthesis of silver nanoparticles was carried out using plant extract. 10g leaves were boiled in 100 ml of water and then 1m ml plant extract was added with 100 ml of 1 mM silver nitrate solution. After 2 hrs colour was changes from transparent to reddish brown, which indicate synthesis of silver nanoparticles. Now my confusion is, how to find out the concentration of nanoparticles?
Anyone kindly give a suggestion.
Dear Dipan Sarma,
The concentration of silver nanoparticles is referred to its mass per ml after finishing synthesis. The nanoparticles need to be washed using solvents such as acetone or ethanol. Then the solutions can be made according to the mass of nanoparticles in a solvent. Some surfactants may add into the solution to make its stable.
Dear Dipan Sarma,
As described by the Xuhua Wang, you first need to wash the silver nanoparticle with water and Ethanol several times by the help of centrifuge machine. After that you need to dry the solution by some means to separate the nanoparticles from the solvent. By drying you'll get the nanoparticles in powder form. Then you can make the colloidal solution of your any desired percentage using the powder of silver nanoparticles.
Thanks & Regards,
I found the following procedure which can be used.
You should specify which type of silver you want to measure.
If you wish to measure total silver (soluble + insoluble) you can performe nitric acid digestion and atomic absorption spectrometry.
If you want to measure soluble silver, you should first ultracentrifuge the solution to sediment the insoluble silver particles. Then use supernatant to measure silver as mentioned above.
Subtract soluble silver from total silver to attain insoluble silver.
If you want to determine silver as ppm scale, you can use all atomic absorption spoctrometry or other similar methods.
Dear Xuhua Wang,
How to re-disperse the nanoparticles powder form into water?
The particles are agglomerated and it may be impossible to adequately disperse the particles. @Xuhua Wang
Dear Ha Bui Thi Thu,
You are absolutely right that once the particles are dried, it is very difficult to redisperse into a solvent. I tried it before. I used a powerful ultrasonic bath to break down the pieces. It took a long time to get a bit nanoparticles into the solvent. I gave up and tried to do from fresh after washed and before the particles were dried to make dispersed solutions. It worked very well.
Hope it helps.
Dear Xuhua Wang ,
You mean that there is no need to dry the nanoparticles, we will use the suspension after washing
I want to evaluate the antibacterial properties of these particles, so how do I calculate concentration of nanoparticles?
Thank you!
Dear Ha Bui Thi Thu,
You could do a small sample to dry out and do parallel comparison, so you should get an estimated concentration.
Xuhua Wang how to estimate the concentration of nanoparticles if they are not settling after centrifugation and remain in the solution only? Is there any other way than centrifugation?
- Badges
- Science topic
- Similar topics
- Phytochemistry
- Extracts