A surface molecularly imprinted electrospun polyethersulfone (PES) fiber mat for selective removal of bilirubin

Electrospinning has been widely recognized as a facile and scalable method for fabricating fibrous materials, which could be used as adsorption materials because of their high surface area. Surface molecular imprinting based on adsorption materials has shown excellent adsorption performance, including large binding capacity, a fast adsorption rate and selective adsorption. In this study, electrospinning and surface molecular imprinting were used together to prepare a surface molecularly imprinted electrospun polyethersulfone (PES) fiber mat (PES@MIP). The mat was prepared by self-polymerization of dopamine (as a functional monomer) on the electrospun PES fiber mat surface in weak alkaline aqueous solution in the presence of a template, bilirubin. The results indicated that a polydopamine coating was formed on the PES fiber mat surface successfully, and the template bilirubin could be removed. The adsorption performance of PES@MIP was investigated in detail, showing a higher adsorption capacity (184.24 mg g^-1), faster adsorption kinetics and a short adsorption equilibrium time of 2 h, as well as a good selectivity toward bilirubin with an imprinting factor (IF) of 1.4. In addition, the selectivity coefficient (α) of PES@MIP toward cholesterol and testosterone could be calculated to be 1.11 and 1.43. Also, both adsorption kinetic and isotherm models were used to analyze the adsorption process. Besides, the dynamic adsorption indicated that PES@MIP adsorbed much more bilirubin, and had a shorter equilibrium time of about 40 minutes for bilirubin removal. In addition, PES@MIP had a much lower hemolysis ratio and exhibited a little anticoagulant property compared to the original PES fiber mat. Therefore, this work provided a new strategy to build practical PES@MIP for bilirubin adsorption.