Monoclonal Behavior of Molecularly Imprinted Polymer Nanoparticles in Capillary Electrochromatography

Abstract

A new approach based on miniemulsion polymerization is demonstrated for synthesis of molecularly imprinted nanoparticles (MIP-NP; 30-150 nm) with "monoclonal" binding behavior. The performance of the MIP nanoparticles is characterized with partial filling capillary electrochromatography, for the analysis of rac-propranolol, where (S)-propranolol is used as a template. In contrast to previous HPLC and CEC methods based on the use of MIPs, there is no apparent tailing for the enantiomer peaks, and baseline separation with 25,000-60,000 plate number is achieved. These effects are attributed to reduction of the MIP site heterogeneity by means of peripheral location of the core cross-linked NP and to MIP-binding sites with the same ordered radial orientation. This new MIP approach is based on the substitution of the functional monomers with a surfactant monomer, sodium N-undecenoyl glycinate (SUG) for improved inclusion in the MIP-NP structure and to the use of a miniemulsion in the MIP-NP synthesis. The feasibility of working primarily with aqueous electrolytes (10 mM phosphate with a 20% acetonitrile at pH 7) is attributable to the micellar character of the MIP-NPs, provided by the inclusion of the SUG monomers in the structure. To our knowledge this is the first example of "monoclonal" MIP-NPs incorporated in CEC separations of drug enantiomers.

CEC separation of ofloxacin enantiomers using imprinted microparticles prepared in molecular crowding conditions

“…Therefore, higher column efficiency can be obtained for CEC-based MIP separations [17][18][19][20]. Furthermore, many formats of MIP can be used in CEC analysis, including monolithic column [21][22][23], open tubular capillary [24][25][26][27] and particle-based technique [28][29][30][31][32][33][34][35][36][37]. For example, using the partial-filling technique, MIP microparticles can be used as additive in the background electrolyte [31][32][33][34][35][36][37] for CEC and has been shown to have higher efficiency on enantiomeric separation.…”

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

“…At present, water compatible MIPs for determination of quinolones in urine, 4,37 milk, 38 river water, 39 and serum 40 have been synthesized. Besides quinolones, propranolol, [41][42][43][44] tetracycline, 45,46 digoxin, 47,48 dopamine, 49 and sulfonamides 50,51 imprinted polymers have also been prepared.…”

“…Combining the concept of molecular micelles with MIT, a remarkably clever approach to ensure homogeneous binding sites was described by Feliciano et al, 42 which is based on substitution of functional monomer with a surfactant monomer by mini-emulsion polymerization. Imprinted nanoparticles for rac-propranolol analysis were prepared by using (S)-propranolol, sodium N-undecenoyl glycinate and EGDMA as template, surfactant monomer and cross-linker, respectively.…”

Microseparation of membrane proteins

“…Since its introduction in the early 1980s, CE has drawn increasing attention of researchers due to its advantages of low sample cost, high separation performance, and ease of system integration and automation. Various CE separation modes have also been developed in the past few decades for enhanced separation selectivity, such as CZE [45,46], MEKC [47,48], capillary sieving electrophoresis (CSE) [49,50], CIEF [51,52], and CEC [53,54].…”