Preparation and characteristics of protein molecularly imprinted membranes on the surface of multiwalled carbon nanotubes

A novel protein molecularly imprinted membrane (PMIM) was synthesized on the surface of multiwalled carbon nanotubes (MWNTs) through a surface molecular imprinting technique by using bovine serum albumin (BSA) as the template molecule, acrylamide (AAm) as the functional monomer, N,N′-methylenebisacrylamide (NNMBA) as the cross-linker and ammonium persulphate [(NH4)2S2O8] as the initiator. The amounts of raw materials were optimized in this paper and the suitable amount is 0.1 g of CNTs, 0.02 g of BSA, 0.24 g of AAm, 0.1 g of MBA and 0.025 mg of (NH4)2S2O8. The selective recognition ability of PMIM/MWNTs was evaluated using adsorption experiments. Maximum adsorption capacity was 5.53 μg/mg PMIM/MWNTs and a saturation value was achieved at a BSA concentration of 0.2 mg/mL. The selectivity adsorption experiments showed that the PMIM/MWNTs also had higher adsorption capacities for BSA than for such molecules, as HSA, HB, pepsin and HRP. The PMIM/MWNTs displayed a 2.6-fold increase in affinity to BSA compared to the nPMIM/MWNTs. The PMIM/MWNTs, on the other hand, did not exhibit any significant change in affinity to other molecules compared to the nPMIM/MWNTs. In the experiment, the characteristics of the PMIM/MWNTs were analyzed using infrared spectroscopy and their configurations were observed using scanning electron microscopy.