Abstract: Molecularly imprinted polymers (MIPs) with core-shell structure for efficient, reliable, and selective extraction of ascorbic acid (AA) were developed via co-polymerization process based on acrylamide (AM) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linker, 2,2'-azobis(2-methylpropionitrile) (AIBN) as initiator, and AA as template. The inorganic core comprised of amino-functionalized silica microspheres (AFSM) was prepared by co-condensation of tetraethylorthosilicate (TEOS) and (3-aminopropyl)trimethoxysilane) (APTMS) in a water-in-oil (W/O) macroemulsion. The synthesized materials were characterized by IR-ATR, SEM, and N2 adsorption-desorption isotherm. The binding properties and selectivity of the AFSM@MIP and AFSM@NIP (i.e., non-imprinted polymers) were demonstrated by adsorption capacity and imprinting factor obtained based on UV-Vis absorption measurements. Furthermore, synthesis conditions were optimized such that imprinting efficiency and adsorption capacity were maximized. Finally, it was demonstrated that generated MIP core-shell hybrid microspheres provide rapid adsorption with high binding capacities (up to 5.08 mg g-1), excellent imprint factors, and exceptional reusability. A comparative study using AFSM@MIP and AFSM@NIP for simultaneous extraction of AA and citric acid (CA), allowed verifying the excellent selectivity of AFSM@MIP, which presented an imprinting factor of 2.30
Author keywords: Core-shell, Porous silica microspheres amino-functionalized, Molecularly imprinted polymer, MIP, Ascorbic acid