How long we can store the nanoparticles (NPs) synthesized using plant extract? Can we store the NPs solution (containing plant part + metallic salt) as well as dried metallic NPs for use in future experiments?
Some plants are available only in a particular season. So is it possible to prepare NPs from the plant at that time and then store them for further use or this will cause NPs degradation?
With Regards
how about freezing the plant on small amounts and prepare the solution from the frozen material, then you can freeze as much as you need and can prepare a fresh solution every time you need it
Plant-mediated metal nanoparticles storage depends highly on a lot of factors that we sadly can't entirely control. The stability of NPs, thus, their ability to be stored longer depends on the chemical composition of the plant as well as the preparation conditions (NPs prepared under alkaline conditions seem to more stable). The plant, the part used in the preparation of NPs, the season of harvest, the chemovar, etc are all other factors that influence the chemical composition of the extract and therefore, the stability of the NPs.
Drying NPs using centrifugation or freeze-drying also is problematic as NPs characteristics (Size, aggregation state) might differ prior to and after the purification.
your best option is to dry the plant when its available (maybe perform the extraction then freeze-dry the extract) and use it later for the preparation of NPs when you want to use it.
If you want to store NPs in a solution, make sure to do so at low temperatures and in dark conditions to prevent photooxidation
If the synthesized nanoparticles from plant extracts are at the small hydrodynamic size at a mean value of < 50 nm with the polydispersity index of 0.2 at average and the zeta potential > 90 mV, they are stored for 2 years according to stability analysis. The stability analysis was performed in an accredited laboratory Ege University Faculty of Science, EGEMİKAL Analysis Laboratory in Turkey. The green silver nanoparticle solution at the brand name Nanoksia is for disinfection of environmental places with Type 2 and Type 4 biocidal licenses was developed from plant extract derived synthesis method.
Bastian Steudel Sir, Thanks for your suggestion. I"ll try to freeze the plant material and prepare NPs when required.
Derya Aksu Demirezen Thanks Mam for such an elaborative explanation.
Abderrahmane Nabgui Sir, You rightly said that I can dry the plant material when it is available. But I have to use fresh plants for NPs synthesis.
Will you please suggest that is it makes a big difference to use fresh plant material or freeze-dry plant extract for NPs synthesis.
Thanks & Regards
Preety Rohilla
Have you explored the option of storage of nanoparticles in vacuum desiccator
Preety Rohilla the standard procedure is to use the dried material extract for the synthesis as it allows you to start with the same concentration (Weight/Volume) if you want to use the same plant later. If you decide to start with fresh material, however, you can't guarantee that the plants harvested later have the same water content (even within the same day). For that reason, I highly suggest using a dried material for the synthesis of NPs (you can monitor the weight difference each day until it no longer changes).
You can also perform the extraction then freeze-dry the extract for further use.
Preety Rohilla
Drying the material will destroy the 'nano-ness' - there are no free independent discrete particles < 100 nm in a powder. See (registration required):
Dispersion and nanotechnology
https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W190528DispNanoMat
Also see this earlier RG question:
https://www.researchgate.net/post/How_to_deagglomerate_the_dry_nano-particle_powder_for_DLS_measurements_How_to_use_a_suitable_surfactant_for_this_purpose
General rule - don't dry 'nanoparticles'.
In terms of stability, then it will depend on the system and storage conditions. Michael Faraday produced gold sols in the mid-1800's that were stable for over 150 years until most were destroyed by bombs in WWII See:
https://www.rigb.org/our-history/iconic-objects/iconic-objects-list/faraday-gold-colloids
The remainder can be seen on display in Faraday’s original laboratory on the Lower Ground Floor of the Royal Institution in the Faraday Museum...
You can sterically stabilize the system with an inert (?) support as in supported PGM catalysts or the Lycurgus Cup in the British Museum.
Hello Preety Rohilla
If we store the NPs solution (containing plant part + metallic salt), microbial contamination occurs eventually, even if we store it at 4 degrees Celcius (fungus may develop due to the presence of plant parts). Before storing it in solution form, the solution must be washed several times with DI water and Ethanol to prevent contamination. Drying the particles will cause aggregation.
- Badges
- Science topic
- Similar topics
- Phytochemistry
- Extracts