A ring-like hollow porous molecularly imprinted polymer for highly selective clean-up followed by influential preconcentration of ultra-trace glibenclamide from bio-fluid

Molecularly imprinted polymers (MIPs) have attracted much attention for their outstanding mechanical and chemical robustness, cheap and easy synthesis, and high selectivity to target molecule [1, 2]. Traditional MIPs have been prepared by bulk polymerization methods, resulted in macroporous monolith materials. Recently, surface imprinting strategy based on hollow porous polymer has been developed in the recent years [3]. Combination of molecularly imprinted technology (MIT) with hollow porous polymers preparation strategy can lead to highly porous MIPs structures; possess in higher sorption capacity as well as faster kinetics to efficient uptake of target molecules from complex matrices. The main advantages have been recognized in the use of porous polymers, correspond to high density of effective recognition sites on their surface, facilitating in the effective transport of analyte.In the present work, a ring like hollow porous molecularly imprinted polymer (R-HPMIP) was prepared via adopting a sacrificial support approach using glibenclamide (GB) as a template, methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate as a cross-linker (EGDMA), and mesoporous MCM-48 nanospheres as a support. Owing to a short thickness of the foresaid HPMIP ring, a suitable steric structure was readily provided, causing a fast and effective mass transfer of target analyte and consequently a highly acquirement of binding capacity. After ultrasonic-assisted dispersive solid phase extraction of urine sample, the analyte of interest was quantitatively determined by high performance liquid chromatography-ultraviolet detection (HPLC-UV). Factors affecting the extraction efficiency such as sonication time, sample pH, sorbent dosage, and volumes of eluent and washing agents as well as their significant interactions were simultaneously optimized by experimental design methodology. Under optimized conditions, a wide linear range 10-3000 µg L-1 was accurately obtained in human urine samples with a satisfactory detection limit close to 3.5 µg L-1. The inter-day precision of the current method was presented as a coefficient of variation lower than 5%.