1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) imprinted polymer was prepared as microspheres by precipitation polymerization method to obtain molecular recognition systems based on the noncovalent interactions between DBU template, methacrylic acid (MAA), and ethylene .glycol dimethacrylate (EDMA) in acetonitrile. 1H NMR analysis of DBU/ MAA mixture has been performed and hydrogen bonding interactions have been established. Microspheres have been characterized by FTIR studies with evidence of DBU linkage in polymer particles and by Scanning Electron Microscopy (SEM) to study their morphological properties. How pH values affect the binding capacity of imprinted polymer during the binding stage has been also discussed and results suggest that imprinted poly-(MAA-EDMA) behavior is related to the influence of DBU basicity during rebinding processes and the optimum pH value for binding has been found around neutral range. Binding ability of the imprinted polymer towards different concentration of DBU buffered solutions has been evaluated and compared with binding ability of the nonimprinted polymer. A more sensitive response to the template in the imprinted system suggests that a reasonable number of specific binding sites is formed. Finally, differential selectivity towards other less strong than DBU nitrogen bases, such as pyridine, imidazole, and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) has been also discussed. Our results indicate that both specific sites and basic properties are involved in the rebinding process
Non-covalent imprinted microspheres: Preparation, Evaluation and Selectivity of DBU Template.
DEL SOLE, Roberta;DE LUCA, Agnese;MELE, Giuseppe Agostino;VASAPOLLO, Giuseppe
2007-01-01
Abstract
1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) imprinted polymer was prepared as microspheres by precipitation polymerization method to obtain molecular recognition systems based on the noncovalent interactions between DBU template, methacrylic acid (MAA), and ethylene .glycol dimethacrylate (EDMA) in acetonitrile. 1H NMR analysis of DBU/ MAA mixture has been performed and hydrogen bonding interactions have been established. Microspheres have been characterized by FTIR studies with evidence of DBU linkage in polymer particles and by Scanning Electron Microscopy (SEM) to study their morphological properties. How pH values affect the binding capacity of imprinted polymer during the binding stage has been also discussed and results suggest that imprinted poly-(MAA-EDMA) behavior is related to the influence of DBU basicity during rebinding processes and the optimum pH value for binding has been found around neutral range. Binding ability of the imprinted polymer towards different concentration of DBU buffered solutions has been evaluated and compared with binding ability of the nonimprinted polymer. A more sensitive response to the template in the imprinted system suggests that a reasonable number of specific binding sites is formed. Finally, differential selectivity towards other less strong than DBU nitrogen bases, such as pyridine, imidazole, and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) has been also discussed. Our results indicate that both specific sites and basic properties are involved in the rebinding processI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
