Preparation And Evaluation Of Molecularly Imprinting Nano-membranes With Multi-selectivity

Objective：Food, water and soil contain low doses of environmental estrogens BPAand TBZ. Trace BPA and TBZ can be enriched through food chain. Sensitive andaccurate detection of trace BPA and TBZ in environment is important to evaluate thepotential environmental risk of these two pollutants. However, interferences inenvironment will significantly affected the sensitivity and accuracy in detecting tracepollutants. Methods that can selectively and simultaneously separate and enrichseveral pollutants are in great need.Molecular Imprinting Technology (MIT) is atechnique to design artificial receptors with a predetermined selectivity and specificityfor a given analyte, which can be used as ideal materials in various application fields.Molecularly Imprinted Polymers (MIPs), the polymeric matrices obtained using theimprinting technology, are robust molecular recognition elements able to mimicnatural recognition entities, such as antibodies and biological receptors. In most cases,MIPs are made only for recognition of one predetermined target. The single molecularspecificity of MIP can be a serious limitation when several classes of compounds needto be extracted simultaneously, as for example in solid-phase extraction for analyticalsample preparation. To improve the efficiency of solid-phase extraction, MIPs that areselective for multiple analytical targets are highly desirable. Multi-templateimprinting (using several templates at one time) requires careful optimization of thesynthetic conditions, because the molecular imprinting effect for each template canvary dramatically depending on its chemical structure.Methods：In this study, molecularly imprinted nanofiber membrane (nano-MIM) thatcan selective and simultaneous separate and enrich BPA and TBZ was perared. Binding characters of these membranes were also evaluated. The main contents of thiswork included:1. A series of MIPs microspheres were prepared by precipitation polymerizationusing BPA, TBZ, or BPA+TBZ as templates. Morphology, selectivity and bindingcharacters of each MIP was evaluated.2. Different nano-MIMs were prepared by encapsulating different MIPsmicrospheres into electrospun polyvinyl alcohol (PVA) nanofiber membranes.Results：The equilibrium binding analysis results show that D-MIM prepared from thedual-template imprinted nanoparticles also displayed lower binding capacity (Bmax)and selectivity (IPB) for BPA and TBZ than membrane containing two single-templateimprinted nanoparticles (B&T-MIM).Conclusions：B&T-MIM can be used for selective adsorption of trace acidic pollutantBPA and alkaline pollutant TBZ simultaneously.