Questions related to Nanoparticle Preparation
I know that k-1 is used to measure the Debye length in an aqueous solution of salt. k-1 is affected by valency and concentration of salt. However in the case of different nanoparticle (say silver nano particle), is there any standard formula or model to calculate the Deby length for the same?
I followed the below attached protocol for synthesis of Chitosan nanoparticle. However after 12 hours of continuous lyophilisation I didn't get it in the powdered form.
How does chitosan nanoparticle look to the naked eye? Do they look like a powder?
Specially for preparation metal oxide nanoparticles using co-precipitation method. If crucible is open, then there may be risk of contamination inside the muffle furnace. I want to clarify this point.
We were surprised during the preparation of magnetite (Fe3O4) usung the co precipitation method
During the preparation, we started as usual with 1:2 ratio of Iron II and iron III
salts , we added the ammonia under N2 and everything is perfect
When we used ethylene diamine to functiolize the surface, things went OK and we got the beautiful black Fe3O4 NPs . But when we used phenyl diamine, it did not work and the stuff was oxidized to brown Fe2O3!
I am a scholar and want to perform antimicrobial activity of silver nanoparticles prepared from mango plant. Do I have to perform MIC for this or antimicrobial activity can be performed directly?
Increasing unimer concentration for micelles preparation leads to increase of micelle size or increase in number of micelles? What are the mechanisms that dictate the behavior of the micelle population when the unimer concentration is increased (e.g. polymeric micelle)?
Hi fellow researchers,
I am currently synthesising graphene quantum dots from glucosamine hydrochloride (I had chosen this based on some past literature so that I can dope my GQDs with Nitrogen and enable them to emit in the NIR region).
I had tried 6 batches of GQDs but always had the problem of losing fluorescence after dialysis. The crude that I get immediately after microwaving, however, is able to give me desirable colour upon 365nm UV illumination (and it matches the images that past literature have reported). The crude also matches the expected UV-Vis and fluorescence spectra. After dialysis however, the absorbance is close to 0.1 au and tapers off. Emission fluorescence is also very low (less than 6000 RFU). So I am starting to wonder if these papers did really dialyse their samples, because dialysis always causes GQD fluorescence to be lost.
I will explain the details of the optimisations I have tried and the results I have gotten. I really hope someone out there could give me valuable advice on how I may retain the fluorescence of my GQDs.
1. I perform the microwave-assisted hydrothermal method. Due to the configurations of my microwave, I have only been able to try heating at 550W or 330W. For 330W, I used 0.14M glucosamine hydrochloride in water (~66mL) and heated for 25 minutes. Heating beyond this duration causes extensive sample evaporation (as I do not have a microwave acid digestion vessel; I only use a regular glass bottle with lid).
2. I filter the resultant solution with a 0.22um string filter before dialysing for 24 hours. I changed the dialysate once every 30 mins for the first 3 hours, and had two more water changes for the remaining duration.
3. I also did another batch in which I did not dialyse, but instead used a Mr<5000 PD-10 desalting column to spin filter my sample. This sample also visually had some fluorescence quenching, but the absorbance and fluorescence spectra were much, much better than the dialysed samples.
Based on these preliminary results, I am thinking of a few modifications I can perform. I hope you can help to verify if these modifications would be helpful or redundant:
1. Should I necessarily use a microwave digestion vessel instead of the regular lab glass beaker with lid? I am still awaiting the digestion vessel but it will take at least 2 months to arrive and I cannot sit around waiting for it. Would the glass beaker with lid be sufficient for controlled microwave-assisted heating of my sample?
2. Should I perform dialysis for a shorter duration? Maybe around 3 hours? Because the desalting procedure of purification took around 2 mins only and I did not lose much fluorescence, absorbance spectra was ideal. I do not know if 24 hour dialysis is causing the fluorescence to lose much.
3. I have yet to do the TEM to verify if my GQD are indeed retained. Even if I can confirm the existence of my GQDs via TEM, I really need the quantum yield of GQDs to be high for diagnostic purposes.
4. Should I dissolve the glucosamine hydrochloride in PBS (my supervisor advised the a buffer might be able to help GQD better retain its fluorescence than water)?
5. I am also going to try other precursors like L-glutamic acid and glucose to generate my GQDs. But I am afraid I might face the same issues after dialysis. So I would like to optimise the dialysis parameters for my current precursor synthesis first before moving on to others.
6. would sonication of glucosamine and water before microwaving cause better dissolution of the sample and perhaps give a better result after microwaving and dialysis
7. This might be a rookie question, but is dialysis the only way I can purify my GQDs? There is no doubt that this is the most widely employed method, but some papers also did sephadex filtration (or some have not even performed any kind of purification which I find very dubious). I would just like to retain the fluorescence of my GQD as much as possible after dialysis is performed.
I have attached my preliminary results with this post so that you can refer to it.
I really, really hope someone can help me and it will be great if I can see positive results afterwards:)
Thank you in advance!
Most of the research using trisodium citrate to reduce Ag ion and its act as stabilizer. How if we replace trisodium citrate to sodium citrate monobacis? How is the chemical equation be?
Some was used both trisodium citrate and sodium borohydride in synthesize Ag nanoparticles. What if we used both trisodium citrate and sodium borohydride?Will both of the reducing agent take part in reaction to form Ag nanoparticles?How is the chemical equation be?
What are the advantages of linking peg to a polymer to form a nanoparticle vs nanoprecipitation? (apart form the fact that the link in the former is chemically stronger)
The particle sizes of Nano/micro-particles measured using DLS and SEM differ greatly, i.e., around 80 nm was determined by DLS, while the same sample measured according to SEM imgae showed a size around 300 nm. Why?
Clear circular particles were observed from SEM, no aggregates, as very low particle concentration was used.
Hello, I'm working on interactions of some inorganic metals/compounds with some protein of interest. Here the ligand are in nanoparticle form. So as for ligand preparation for docking these need to be in nanoscale range, is there any procedure for preparing it ?
Please suggest some user friendly software other than Vesta if possible!
Thanks in advance.
The fate of nanodrugs / nanoparticles in vivo draws a lot of attention, and many studies label fluorescent of nanodrugs / nanoparticles in order to disclose their distribution in vivo.
- What are its advantages and disadvantages ?
- Is it a reliable tool ?
I've used chloroform to dissolve the MnO2, but it doesn't work. Are there any volatile solvent can dissolve MnO2?
Ive never made micelles before, but I gave it a go today and now I have some questions. I am generating thin films using my polymer solubilized in chloroform, evaporating in a rotovap, and then resolubilizing in water followed by 30 min of sonication. I currently (very sadly) do not have access to DLS, I am thinking about getting the Lens3 from Tosoh and analyzing my particles using MALS very soon, until then I dont have any physical characterization assays setup. As a very general description of my molecule, I have conjugated a hydrophobic molecule onto a cationic/hydrophilic polymer
1. What size flask is appropriate for 2mgs of polymer? I tried 100mL, 250mL, and 1L. the 1L sized flask was a bit cumbersome to do the hydration in and the thin films from the 100 or 250 mL flask dont look that thin
2. How quickly do I add water to the solution? Dropwise or all at once?
3. Should i start sonicating the micelles as they rehydrate? Should I rehydrate and then wait and then sonicate?
4. Does adding salt to micelles during hydration or after hydration change particle size?
5. How stable are cationic micelles in general in water or buffer? Hours? Days Weeks? The paper im referencing has no stability data
6. Are there any solvents that are not acceptable for forming thin films/micelles? Variants of my polymer are soluble in ethanol but not in chloroform so can I use ethanol instead?
Im still going through all the literature to find answers to some of my more basic questions, but any useful papers you can recommend would be very much appreciated and a big time saver for me!
I have made chitosan nanoparticles and harvested the nanoparticle by centrifugation. After that, I need to dissolve the pellet back again into aqueous solution, but the pellet wont completely dissolve. What solvent must I use to get chitosan nanoparticle to completely dissolve? What methods must I apply? Is it possible only using vortexing or do I need to use a sonicator (probe sonicator)?
Nanoparticles prepared from ZnO and Mushroom . Am I also check antifungal activity in a room temperature ?? Please guide me , I am patiently waiting for your kinds suggestions .Thanks in Advance.
I am an M.Pharm student, currently pursuing a research project. I am trying to make Hesperidin-chitosan nanoparticles, but, it was failed attempt as Hesperidin is getting precipitated in the acidic environment and chitosan is soluble only in an acidic environment (I used 1% acetic acid).
So, I added HPBCD to tackle this problem, and now hesperidin is not precipitating. However, the entrapment efficiency of nanoparticles prepared this way is too less (almost 16%) And the Zeta potential is too large (almost 34).
Can anyone please suggest what can be the next to right approach? Any suggestion would be of great help.
Lots of methods are reported for the preparation of the nanoparticle, but as we know nanoparticles have the big issue of particle size and consistency in stability over a prolonged period of time. Therefore, if anyone has any strong suggestion in this regard then please answer.
How the the defects like oxygen vacancies and structure distortion from its original, un saturated bonds. particularly in Ferrites (Ni, Zn ferrites) can effect lattice parameter?.
I have prepared a 0.3 mg/ml GO suspension in THF by freeze-drying a stable GO/water dispersion, probe sonicating for ~15 minutes, and water bath sonicating for 2 hours, followed by stirring overnight. However, the suspension still settles very quickly (<5 minutes) and is cloudy. When tested with DLS, the sheet size seems to be ~300nm before it settles. Any idea how to fix this, or what the problem could be?
I have read papers where the suspensions are stable for >24h by simple water bath sonication for 1 hour.
Since I am from a physics background, I can understand physical treatment and fabrication methods of nanoparticle synthesis like arc discharge or lithography. But recently I have undertaken Sol-Gel and Hydrothermal synthesis of metal oxide nanoparticles. Let me show you and Fe- Sem image of WO3 nanoparticles. This is synthesized using the Sol-Gel technique. If the precursor isn't a typical metal alkoxide then the further reaction falls flat on literature.
Like I have used Sodium Tungstate (Na2WO4.2H2O) as a precursor. Now the acid would have a specific role, so would the capping agents, so would the rate of rotation in magnetic stirring. Even if I somehow figure out the chemical reaction, there would be a particular variable that could have been highly significant while others not so much in causing the structure to form. How do I develop a chemical intuition regarding the result? How can I reason the structure that is formed if I know the chemicals used. Is there perhaps a direct correlation between stoichiometry and structure? Kindly Suggest some literature that can help me.
I am working with lipid nanoparticles encapsulated with RNA and I need to calculate the N/P ratio for their preparation.
However, the literature is not very clear on how to calculate it. Does anyone know the standard equation for calculating N/P ratio, please?
Thank you very much,
What is a good dispersant chemical that is for slurry preparatoin of ceramic nanoparticle (alumina, zirconia, SiC, etc.) to reduce the slurry viscosity?
It will be great if it's commercially available in US and for lab small batch purchase.
Most of the reported mixed metal oxides are prepared from their precursor materials. I want to prepare mixed metal oxides from already prepared metal oxide materials. For example, CaO and Fe2O3 are available commercially, I want to combine them together via a suitable chemical method like making a core-shell structure, or CaO coating on Fe2O3 surface. Please give me an idea on how to make mixed metal oxides from prepared metal oxide and send me any reference articles.
I am trying to synthesize CS NPs by ionic gelation method using TPP but I can not get PDI under 0.3. what am I doing wrong? here is my method till here.
my sizes are good and under 300 nm mostly. even though I use filtering (0.22 nm filters) and sonication and centrifuge. and I dilute my sample before testing for getting a more transparent solution.
the Conc of my LMW CS is 1 mg/ml (solvent 10 cc acid acetic 0.1 %) and Conc of TPP is 0.5 mg/ml (solvent 10 cc deionized water).
I let the CS to dissolve overnight on the heater stirrer with temperature 30-40 C. the next dey I have a transparent CS solution. after dissolving the TPP by stirring for about 10-30 min at RT, I add TPP dropwise to the stirring CS solution. I used syringes sometimes but the rate of adding was too rapid I think and by using burette I could control the rate but I think it was still high and with bigger drops. all of TPP solution will drop in about 4 min into the CS solution. how should I add TPP? with such rate and what equipment? after adding TPP, I let the solution to stirr for 1 h in RT in 7000 rpm trying to have a balanced stirr. and then I centrifuge for 5 min, 6000 rpm, after that filtration and sonication for about 2 min.
so now here is my QAs:
1. is there a special environment to work in to be sure that I am avoiding external Contaminations?
2.how should I add TPP? syringes? special made burette?
3.how can I control the rate of adding TPP? and how many drops per min?
4.is the rate of stirring(7000 rpm) while adding the TPP ok?
any suggestion will do
sorry for the long description
I have an experimental setup with which I am trying to get optical absorbance spectra of gold nanoparticles. From right to left, I have a light source (Ocean optics HL 2000), a collimating lens, an iris, a long glass tube through which the light passes via two flat faces at entry and exit sides (approx 1 meter long) and a spectrometer (FLAME VIS NIR). I am using a blank substrate of quartz as a reference and the sample substrate contains dried and drop-casted Au nanoparticles (prepared by simple NaBH4 reduction). I am unable to get smooth absorbance spectra and instead am only getting undulating curves, as shown in the attached image. I am unsure of what is going wrong with my acquisitions, and any help in this regard will be greatly appreciated.
I am trying to make a Silver nanoparticle covered with FMN ligand. I tried docking using AutoDock but only a molecule can be docked on the nanoparticle but more than hundreds are required to cover whole surface area.
Is there any other way to create this kind of structure?
Any advice will be helpful.
In UV-Visible measurement , blue shift was observed at absorption edge of ZnS nanoparticle prepared by CBD (chemical bath deposition ). On the other red shift was found in the PL spectra of the same specimen. Why do we have this two different phenomena in the same specimen when they were characterized by UV-visible and PL spectroscopy ?
I was trying to design a nanocluster of 10 nm diameter using Material studio(MS) software. Due to the lack of the "nm" size option in the material studio, I have used a 50Å (angstrom) radius option available in MS to construct the nanocluster. I was confused when I found 60000 atoms in the generated nanocluster of size 10 nm diameter (100Å). Whether my conversion (nm to Å ) is correct or the Å mentioned in MS is different from my conversion?. I have doubt that a 10 nm-sized nanoparticle will have 60000 atoms in its cluster form. Please help me with this issue.
I want to know why the PLGA nanoparticle prepared by double emulsion method have not stability in water.
I have used 20 mg of PLGA in DCM and acetone and mixed with 1 mg of Doxorubicin-HCl(O/W1) and sonicated for 1 min at 38% amplitude and then added the mixture in 5% PVA and sonicated for 10 min at 88% amplitude. Then this whole mixture is mixed with 10 ml of 0.1% PVA again and stirred for 16 hrs to remove DCM-acetone. Then centrifuged at 18000 RPM for 20 min and washed with water thrice.
The particle is soluble in water or PBS. But gradually settles at the early hours of preparation in room temperature . Can any one please tell me what could have went wrong in this or what can be done to stabilize this?
Palladium chloride salt is very less soluble in water so I add diluted HCl solution to dissolve the salt but it also increases the acidity of the solution. I am preparing Pd NPs by reverse micelle method but no success yet. My solution stays turbid for a long time. micelles are not formed. Is it because of the high acidity?
I want to ask various techniques of separation of nanoparticles, I think different nanoparticles have different stability therefore different techniques should be used for separating them. Thanks in advance.
I have successfully synthesized lanthanide up-conversion nanoparticle using hydrothermal method, they are hydrophilic in nature with positive surface charge as confirmed through DLS.
I want to make surface charge negative.
I know there are lot of articles about surface functionalization, but most of them are related to switching from hydrophobic to hydrophillic.
can anyone please share the relevant information about it?
I have found an article where cobalt ferrite (CF) was coated with gold. There,firstly cobalt ferrite was synthesized and then coated with Gold. So, could I replace cobalt ferrite by zinc ferrite (ZF) using same methodology? However, I have also prepared zinc ferrite NPs individually. So, could I follow the methodology used in CF-Au to coat ZF using gold. Since, gold and cobalt close to each other.
Then how do I conjugate/add/coat copper with ZF-Au nanocomplex/ on the surface of ZF-Au nanocomplex? Please give me any methodology.
Thanks in Advance
I am currently trying to figure out how i can use an Anasys Instruments NanoIR2 instrument to characterize my chitosan polymeric nanoparticles. Is this a possible instrumentation to use, or should i use something else? If i do use it, what is the best method of preparation of the nanoparticles to get optimum results on the instrument? Protocals and papers are welcome. Thank you!
I am trying to dry the silver nanoparticles prepared from fruit extract after centrifugation process. The petri plates were kept in drying oven for 70 degree Celsius for overnight. I am still not getting the dried form and the amount is less.
BSA loaded chitosan nanoparticle was prepared using TPP ionic gelation methods. The lyophilized nanoparticle powder was assayed for drug release in (pH 7.5 or pH 5.0, 37℃, RPM 150) PBS , but the nanoparticles did not dissolve. What should i do? T.T
I am working on nano-particle preparation of silver sulfide. I have a silver particle around 10-micron meter. I am continuously triturating in with the help of the ball mill but unfortunately, I could not prepare the particle at 20 nm range. I have prepared at the level of 400 nm silver sulfide nanoparticle with the help of trituration. What should I do..
I have synthesized ~150 nm polystyrene nanoparticles with carboxylic groups on the surface. I used EDC chemistry to cross-link the carboxylic group with protein. After the reaction, I used Tris to quench EDC and Tween 85 to block the unbound sites. I also used sonication to break any aggregation. However, after about a week, the nanoparticles started to aggregate again.
I was able to coat ~5 mg of iron oxide nanoparticles with silica. After increasing the quantities (ten times) I lost uniformity and the particles were agglomerated. So, can anyone suggest how to synthesize water soluble, monodispersed, silica coated iron oxide nanoparticles( 30-70 nm) on a large scale?
If anyone prepared before copper nanoparticles from copper chloride and ascorbic acid, I tried the method different times but always I get copper oxide, how to get rid of this or how to prevent its formation ? Is there any tried easy method to do that ?
In a paper, I saw the synthesize of silver nanoparticles using ethanol and PVA(poly vinlyl alcohol). I exactly followed the same procedure as they did. But, as ethanol is very volatile, most of the ethanol is lost by evaporation during the synthesizing procedure because it requires heating. How do I overcome this problem?
I am attaching the paper
I have some problems about producing ordered-magnetic silica core/shell nanoparticles. I attached a file what I have done also I added the references that I used to synthesis.
I tried different protocols but still i could not obtain monodisperse and ordered core/shell nanoparticles. I observed aggregated NPs as well as worm-shape NPs. I kept the samples in an ultrasonic water bath for 1 hour before TEM analysis. Furthermore, I could not see the silica shell clearly in TEM analysis, even if the nanoparticles were well dispersed in water.
Does anyone have idea why I have shapeless NPs and what is the crux of getting core/shell NPs?
Thank you in advance!
My test drug is insoluble water ( lipophilic). I want to load the drug to target brain mitochondria?
1. Which nanoparticle will be more appropriate?
2. how to confirm the drug loading?
Iron oxide nanoparticles show magnetic properties. Are nanozerovalent iron nanoparticles also magnetic in nature?
I need to conjugate gold nanoparticles with either a peptide or folate but need a linker between these and the gold. What ratio should I use to make the thiol react with the gold? What concentration of thiol should I use? I have Cyclohexane thiol from Sigma Aldrich.
This is all about the preparation of silver nanoparticles by sodium citrate reduction of silver nitrate in aqueous medium.
I want to understand the concept of nanoparticles. nanoparticles are considered better due to their size but as nanoparticles are prepared from corresponding ions by taking up electron through reduction process. further, in bottom up process, nano-atom is agglomerated to form colloidal metal nanoparticles. if we consider the size as only criteria to consider nanoparticles as better choice in many applications, then ions are smaller in size compared to its nanoparticles.
please explain the concept....
we may faced problem in removing plant extract from silver nano particles. If we check pharmacological activity as such we may not able to discuss the exact mechanism by which these particles show the activity.
I have produced silver Nonparticles from Bacteria , but I cant get the Nonoparticles to use it in farther applications .
How can i get it from the solution ? I have tried cooling centfugation at 4c for 15 mins but it just gave me a brown color on the wall of the eppendorf, and the weight of the eppendorf doesn't change( before and after ) . what should i do and how can i get large amount from the Nanoparticles ?
For purification of silver nanoparticles through centrifugation,
After centrifugation at 12,000 rpm for 30 mins, it is diffcult to disperse again in water for washing to remove unwanted reactants. What is the possible solution for this?
Does it cause agglomeration at high speed (12,000 rpm)?
What is the recommended speed (rpm)?
How to dry the nano silver after centrifugation?
I am interested in the synthesis of oligosaccharide nanoparticles. In literature Chitosan has been used to synthesize its nanoparticles and conjugated metal nanoparticle. Does amine group has any role in formation of its nano form? I request the experts of this field to guide me/ share the methods used for synthesizing and stabilizing carbohydrate (oligosaccharide) nanoparticle.
Tried to prepare quercetin nanoparticles with Poly allylamine hydrochloride , incubation was for .5 hour , but after centrifugation for 10 mins at 10,000 rpm got false pellet . what could be the possible reasons for this spoil ?
I find many researches emerging on the hybrid nanofluids wherein the nanoparticles are taken and mixed in conventional fluids. But I do not know the chemical or physical constraints to be taken into account while choosing such particles. Kindly let me know the clear micro-structural phenomenon by which two or more nanoparticles could be chosen for preparing the hybrid nanosuspensions.
@ Nermin Zakhas asked me a question via PM, and as this forum is not a consultancy service, I will post so all experts can contribute.
Dear Dr. Alan,
I am trying to prepare magnetite nanoparticles using coprecipitation method and NaoH. Malvern analyzer showed good size. The zetapotential showed positive 17 mv. Can you please help me with might went wrong ? Is not magnetite nanoparticles prepared with alkaline medium should be negatively charged ? How can i overcome this ?
Thanks a lot for your time and help.
Ive bought gold nanoparticles in the past but feel a higher concentration would be interesting to work with than is currently feasible for me to buy commercially. If I purchased a gram of chloroauric acid what kind of final amount of 10nm nanometer gold nanoparticles would I, realistically as someone who is familiar with the synthesis only through examining the literature, be looking at? If anyone has examples of stock solutions theyve created thatd be great.
Thanks for your time
This is my first attempt at making PLGA nanoparticles using the nano precipitation method. I've developed my protocol based on a variety of papers I've read online.
I'm using dichloromethane (DCM) for my solvent, and followed a simple protocol: dissolve 100mg PLGA into 10 ml DCM. Slowly add PLGA solution via drop wise addition (20 ml/hr) into stirring DI water. Evaporate DCM in hood stirring for 2 hours. Centrifuge at 15,000 RPM for 30 minutes to collect nanoparticles.
Unfortunately I wasn't able to collect any nanoparticles, and during my formation a sticky white residue formed at the surface of the solution and on the sides of the beaker. Is this something that you've seen before? Any idea how to stop it from happening again? Thanks.
I am using PVP as a capping agent for nanoparticle preparation. How can I remove PVP after formation of nanoparticle, which is supported by carbon material? Thanks!