For example by comparing the FTIR or Raman spectrum of the initial solution and the reacted.

If you want to kn ow whether you made NPs, then put a sample in a (FEG-)SEM.

PS: It would help if  next time you cite the article.

I agree with  Michael Päch, the crosslinker concentration is vey high comparing to the monomer. The amount of AIBN is very high too . I might try 1HRMN.

 to do a 1H NMR test

Hello Alexander, thank you for your suggestion surely I follow it,  here is the link for my reference article.

http://pubs.rsc.org/en/content/articlehtml/2012/jm/c2jm15680f

Michael Päch and Inmaculada Aranaz, you can see the reference I quoted.  It didn't form any precipitate even after carrying out the reaction for 24 hrs. but today I have observed the gel-like substance formed after adding water into the Batch 2 formulation and I have dried it under nitrogen gas and  powder which is now insoluble in the water 

Hi Yanfei Hu, will H1 NMR helps to know the degree of polymerization ?

ofc, you can calculate the conversion from NMR

The reason for your polymerization solution remaining clear may be many; such as, the initiator (Catalyst) may not be appropriate, The selection of solvent is not good etc.

The most important is that you are handling a water soluble monomer. In your case the crosslinked polymer, if formed, remains swelled like a dissolved material.  The crosslinker must be minimum 4 times and in some cases up to 8 times. You will get solid mass. High amount of crosslinker is required to stabilize the polymer so that in eluting solvent, during further studies, does not swell. The swelling changes the cavity structure and sensing/selectivity will be eratic. .

I am not familiar with the chemistry of your polymerization, but since you are talking about a clear solution, dynamic light scattering is a good method to verify and follow up the polymerization process.

This time I have changed the solvent since the drug of my choice is not soluble in acetonitrile; I have tried with DMF. Similar to the previous  experiment I have added 40 ul- MAA, 200 ul- EGDMA, 15mg-AIBN and kept for 24 hrs reaction at 60*c temperature. I got gel-like a polymer this time, instead of micro or nanoparticles. may I know the reason behind the gel formation.

As I have mentioned earlier, you must take 4-8 times crosslinker (EGDMA) as compared to monomer (MAA) to make crosslinked polymer whose solubility is almost negligible. The ratio being less earlier it was formed but did swell only ant precipitating. The solvent selection also plays a great role as it needs to solubilize monomer (MAA) and not a good solvent for polymer. In your case the  drug  first forms stable complex with monomer and later allow it to polymerize and crosslink. The selection was proper in this case.

Asit ji, you mean gel formation is due to the lesser amount of EGDMA... is there any role of DMF in gel formation, why because the same ratio of ingredients in acetonitrile is forming nanoparticles( as it was mentioned in an article)...?

EGDMA amount is almost same in both experiments. The solvent is playing its role by maintaining stability of initiator radicals and monomer radicals and allowing the crosslinking and polymerization to go to high molecular weight. At higher molecular weight and also in crosslinked state the solvent is not able to hold it in solution and it precipitates. It is thus combination of factors; earlier solvent was not allowing to achieve high molecular weight and was able to keep lowly crosslinked polymer in solution or swelled state.

Recrystallize it and then you can use it, otherwise if your solvent for the polymerization is acetone you can use it as it if you know the concentrartion of AIBN in acetone.

Sandeep Urandur and Asit Baran Samui

I have a question, can I use any amino acid (monomer itself) to polymerise on imprinted surface? because some researchers have been utilized the dopamine after imprinting protein template without using any cross linking agent and radical initiators.

Thank you

Hello Lingaraj Sir, I think we can't use amino acids as a functional monomers. The reason behind that is, the main criteria required to be a monomer is presence of vinyl group. But amino acids doesn't contain that. So we cannot use them as a monomer. Dopamine you have mentioned, was used as a template but not as monomer.

Dear Sandeep Urandur Thank you .

Here I have attached a file please take a look.

Actually amino acid can utilize as a functional monomer but point is, is that amino acid going to polymerize without any radical initiator and cross linker in the process?

Dopamine will be self polymerize at room temperature with weak alkaline pH.

I have utillized the L-glutamic acid in the process of imprinting on nanoparticles and FTIR has shown vibrations of glutamic acid functional groups but was really poymerized or just attached to the surface ? need to confirm ,

asking for suggestions.

Dear Lingaraj, One way to confirm the polymerisation has occurred or not is through determination of mass or you can try NMR also.

Dear Lingaraj, I have read the paper you have attached. I can say methylimidazole which they have used was a real monomer used for the MIP purpose, and dopamine was used for just forming a polymer. However, dopamine cant acts as a molecule to be used in molecular (template) recognition that really happens in molecular imprinting technique which is a type of "lock and key" model.

NMR is what your need!

Dear Sandeep Urandur , Imidazole ionic liquid they modified and then then bovine albumin serum used as template protein then after dopamine as functional monomer to polymerize on matrix.

Where methyl imidazole for ionic liquid construction on MNPs which led synergistic effect for protein adsorption.

Dear all, to confirm the occurence (or not) of vinyl/acryl monomers' polymerization, you have simply to titrate C=C double bond spectroscopically and/or chemically. My Regards