One-Pot Synthesis of Hydrophilic Molecularly Imprinted Nanoparticles

Abstract

Molecularly imprinted nanoparticles were prepared using a simple distillation precipitation polymerization method. In this work, propranolol-imprinted nanoparticles were synthesized using different cross-linkers combined with methacrylic acid (MAA) as a functional monomer in refluxing acetonitrile. Using the new synthetic method, uniform prorpanolol-imprinted nanoparticles were obtained in less than 3 h, which is in contrast to the long reaction time (24 h) required in previous precipitation polymerization. The new synthetic method also provides a convenient means to prepare core−shell structured nanoparticles, where the core contains imprinted binding sites and the shell has more hydrophilic characteristics. Molecular recognition properties of the imprinted nanoparticles were studied through equilibrium binding experiments. For nanoparticles containing N,N′-methylenebis(acrylamide) cross-linker, the residual CC bonds remaining in the nanoparticles were utilized to immobilize a fluorescent compound, 1-pyrenemethylamine, through nondestructive Michael addition reaction. The fluorescent modification did not deteriorate the molecular recognition property of the nanoparticles, suggesting that the Michael addition reaction took place only in nonselective sites. Using a similar Michael addition reaction, we anticipate that the residual CC bonds in the acrylamide moiety can be utilized to introduce other reporter molecules into molecularly imprinted nanoparticles or to immobilize such nanoparticles on amine- or thiol-functionalized surfaces to develop different chemical sensors. The hydrophilic shell of the imprinted core−shell nanoparticles shall provide effective screening to prevent nonspecific adsorption of, e.g., proteins while allowing small target molecules to enter the imprinted sites in the more hydrophobic core, thereby potentially useful for extraction of small organic molecules from complex biological samples.

Recent advances in molecular imprinting technology: current status, challenges and highlighted applications

“…Long polymerization time was used in order to increase the rigidity of the polymer structure and facilitate the formation of imprinted cavities with better defined shapes. 27 However, propranolol-imprinted nanoparticles were obtained in less than 3 h by using distillation precipitation polymerization (DPP) proposed by Yang et al 114 Unlike TPP performed at lower temperature for 24 h, DPP was carried out in neat acetonitrile under refluxing conditions, with half of the reaction solvent being distilled off in the latter phase of the polymerization.…”

“…37 To further achieve recognition in aqueous media, hydrophilic modification of MIPs surface was proposed, which involved a two-step polymerization procedure. 114,174 Fig. 8 displays the synthesis process of restricted access material MIPs (RAM-MIPs).…”

“…As expected, the hydrophilic external layer formed by the glycidyl methacrylate epoxide ring opening on the polymeric surface reduced the non-specific hydrophobic interactions and increased water compatibility. Ye et al 114 proposed a dramatically ingenious approach to synthesize core-shell structured hydrophilic molecularly imprinted nanoparticles by one-pot distillation precipitation polymerization, where the hydrophobic core contained prorpanolol-imprinted binding sites and the hydrophilic shell was nonimprinted. The hydrophilic shell was grafted to the core particles via copolymerization of the residual CQC bond remaining in the core with the hydrophilic monomers added in the second phase.…”

Polymeric nanoparticles for optical sensing

“…However, MIPs are gaining more and more success in the diagnostic field, due to continuous improvements in their synthesis and in the recognition and quantification process of the analyte (template). (Yang et al, 2009a). By using a distillation precipitation polymerization technique, they synthesized NPs imprinted for R,S-propranolol.…”

Double water compatible molecularly imprinted polymers applied as solid-phase extraction sorbent for selective preconcentration and determination of triazines in complicated water samples

“…The third one involved a post-modification procedure for the preformed MIPs. Surface-grafting of hydrophilic polymer brush or chemical bonded hydrophilic functional groups on the surface of the MIP particles were two commonly used methods [20][21][22][23][24]. For example, Zhang's group [22][23][24] prepared a series of WC-MIPs by grafting of hydrophilic polymer brush, such as poly(N-isopropylacrylamide) (PNIPAM), poly(2-hydrozyethyl methacrylate) (PHEMA) onto the MIP microspheres via surfaceinitiated reversible addition-fragmentation chain transfer (RAFT) polymerization.…”