Preparation of molecularly imprinted polymers
A polymerization process, preferably a living radical polymerisation process, is carried out in the presence of a template substance, to produce molecularly imprinted polymers (“MIPs”). It is controlled so that the products are quite small (500-10 6 Daltons) so that they are soluble or form colloidal suspensions. The template substances are immobilized templates, which can be re-used. Immobilized templates are also useful for purification of MIP solutions/suspensions by affinity chromatography.
1. A process for the preparation of a solution or colloidal suspension of molecularly imprinted polymer (“MIP”) particles comprising the steps of:
(a) providing a carrier substance having a template material immobilized on it so the template is exposed at the carrier substance surface;
(b) providing a polymerizable composition in contact with said template;
(c) effecting controlled polymerization of said polymerizable composition in contact with said template by using a method selected from radical polymerization, optionally controlled living radical polymerization (LRP); living anionic polymerization; living cationic polymerization; and controlled polycondensation; iniferter-mediated polymerization, nitroxide-mediated polymerization (NMP), atom-transfer radical polymerization (ATRP) and reversible addition-fragmentation chain-transfer polymerization (RAFT), said polymerization being terminated when MIP particles of less than 1 micrometer have been formed; and
(d) separating said MIP particles from said template by washing and/or eluting thereby forming said solution or colloidal suspension, wherein said carrier substance and said immobilized template can be reused in additional controlled polymerizations of the type set forth in step (c) above.
2. A process according to claim 1 in which said carrier substance is in the form of beads, the surface of waveguides, fibers, optical fibers, membranes or capillaries.
3. A process according to claim 1 in which said carrier substance is a polymer resin, a polysaccharide, a glass or a metal surface.
4. A process according to claim 1 where said polymerizable composition contains one or more monomers selected from vinyl monomers, allyl monomers, acetylenes, acrylates, methacrylates, acrylamides, methacrylamides, chloroacrylates, itaconates, trifluoromethylacrylates, derivatives of amino acids, nucleosides, nucleotides, and carbohydrates.
5. A process according to claim 4 wherein said polymerizable composition also contains at least one cross-linker selected from ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, divinylbenzene, methylene bisacrylamide, ethylene bisacrylamide and N,N′-bisacrylolylpiperazine.
6. A process according to claim 1 wherein, after step (c), a wash step is employed, whereby the synthesized MIP particles are washed, followed by separation of the synthesized particles from the template and the collection of said synthesized particles.
7. A process according to claim 5 wherein in step (c), polymerization is initiated by heating, UV or visible light irradiation, microwave irradiation, electropolymerization, oxidation or adding catalyst.
8. A process according to claim 1 wherein polymerization is terminated when MIP particles of less than 460 nm have been formed.
9. A process according to claim 1 wherein polymerization is terminated when MIP particles of less than 300 nm have been formed.
10. A process for the preparation of a solution or colloidal suspension of molecularly imprinted polymer (“MIP”) particles comprising the steps of:
(a) providing a carrier substance having a template material immobilized on it so the template is exposed at the carrier substance surface;
(b) providing a polymerizable composition in contact with said template, wherein said polymerizable composition contains one or more monomers selected from vinyl monomers, allyl monomers, acetylenes, acrylates, methacrylates, acrylamides, methacrylamides, chloroacrylates, itaconates, trifluoromethylacrylates, derivatives of amino acids, nucleosides, nucleotides, and carbohydrates, and also contains at least one cross-linker selected from ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, divinylbenzene, methylene bisacrylamide, ethylene bisacrylamide, and N,N′- bisacryloylpiperazine;
(c) effecting controlled polymerization of said polymerizable composition in contact with said template by using a method selected from radical polymerization, optionally controlled living radical polymerization (LRP); living anionic polymerization; living cationic polymerization; and controlled polycondensation; iniferter-mediated polymerization, nitroxide-mediated polymerization (NMP), atom-transfer radical polymerization (RAFT), said polymerization being initiated by heating, UV or visible light irradiation, microwave irradiation, electropolymerization, oxidation, or adding catalyst and being terminated when MIP particles of less than 460 nm have been formed;
(d) washing said MIP particles; and
(e) separating said MIP particles from said template surface by means of heating, changing solution pH, changing ionic strength, or through the addition of urea, guanidine, or a substance which interacts with the template more strongly than does the MIP thereby forming said solution or colloidal suspension, wherein said carrier substance and said immobilized template can be reused in additional controlled polymerizations of the type set forth in step (c) above.
11. A process according to claim 10 wherein said carrier substance is in the form of beads, the surface of waveguides, fibers, optical fibers, membranes or capillaries.
12. A process according to claim 10 in which said carrier substance is a polymer resin, a polysaccharide, a glass or a metal surface.