Preparation and Selectivity Evaluation of Glutathione Molecularly Imprinted Polymers from Aqueous Media

A novel polymer, by molecularly imprinting glutathione (GSH), capable of being directly utilized in the aqueous phase, was developed for uptaking GSH. To significantly improve cross-linking density of this molecular imprinted polymer (MIP), the pseudoternary phase diagram of N,N′-methylene-biacrylamide, methanol, and water was investigated to increase solubility of NMBA. Subsequently, key fabrication variables, including a functional monomer, cross-linker, and initiator quantity, polymerization temperature, and time were optimized. Under optimum conditions, the maximum adsorption capacity of GSH approached 27 mg g–¹, and the separation degree was as high as 2.84. The Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), and Brunauer–Emmett–Teller (BET) analysis results from GSH-MIP and the control indicated that the high adsorption capacity and selectivity of GSH originated from the arrangement of functional groups and cavities. Additionally, this MIP demonstrated appealing long-time stability and reusability. The adsorption kinetics could be well described by a pseudo-first-order model, while the thermodynamics of the adsorption process could be described by neither classic Langmuir nor Freundlich model. The adsorption and separation study was applied in urine, and the adsorption rate was 90.30%, the desorption rate was 75.32%, and the purity was 58.74%.