Construction Of Highly Selective And Highly Sensitive Molecularly Imprinted Polymer Membrane-Based Potentiometric Sensor

BPAF is an analogue of BPA,which is widely used in daily life and industrial production,such as medicine,food packaging and so on.Due to its easy degradation,it has caused some harm to the environment,moreover,it also acts as an endocrine disruptor and is potentially toxic to organisms.Therefore,researchers are increasingly concerned about the detection and analysis of bisphenol AF.Based on this,a soluble molecularly imprinted polymer potentiometric sensor was developed for the detection of ionic bisphenol AF.Using precipitation polymerization and high-temperature swelling methods,the soluble molecularly imprinted polymer synthesized was not only soluble in organic solvents,but also soluble in plasticizer doped with PVC membrane.Soluble molecularly imprinted polymers were used as ionophores to achieve a highly selective and highly sensitive potential detection of bisphenol AF.In order to further improve the detection sensitivity of the molecularly imprinted polymer membrane potentiometric sensor,an ultra-thin membrane molecularly imprinted polymer ion-selective electrode was constructed,which greatly inhibited the diffusion of the analyte from the membrane interface to the membrane interior,making it effectively aggregated in the sensitive membrane layer,thereby the interface potential response of the liquid membrane was significantly increased,and finally a high sensitivity detection of bisphenol AF was realized.The specific research contents are as follows:1.Construction of soluble molecularly imprinted polymer potentiometric sensorSince the synthesis of the conventional precipitation polymerization method is insoluble in organic solvents,this study uses a highly polar solvent 1,2,4-trichlorobenzene(TCB)in hightemperature gel permeation chromatography on the basis of precipitation polymerization.Swelling by high temperature,the obtained molecularly imprinted polymer not only can be dissolved in organic solvents,but also can be dissolved in a plasticizer-doped PVC membrane.The morphological characterization of the soluble molecularly imprinted polymers has a larger particle size distribution with respect to the conventional ones,and this method increases the solubility of the conventional rigid imprinted polymers.The resulting molecularly imprinted polymer was used as a selective ionophore for potentiometric determination of neutral bisphenol AF.In this experiment,the sensitivity of the proposed sensor to the neutral BPAF was significantly improved compared to the traditional insoluble MIP.The linear range of determination for neutral bisphenol AF was 0.1~1?M,and the detection limit can up to 60n M(3?/S).In addition,the sensor shows good selectivity for other neutral phenols.2.Detection of ionic bisphenol AF with ultrathin membrane ion-selective electrodeThe thickness of sensitive membrane is about 200?m,organic molecules are extracted into the membrane phase,and easily diffused from the liquid membrane interface to the inside of the membrane.At the same time,the free indicator ions and the complex indicator ions of the membrane also occur ion-exchange,which does not effectively accumulate at the sensitive membrane interface,accordingly significantly enhancing the sensitivity.In this experiment,a solid-contact ultra-thin membrane potentiometric sensor was developed to detection the ionic bisphenol AF,and the sensitivity is significantly increased by the ultra-thin membrane ionselective electrode.The proposed response of potentiometric sensor has a range of 1.0×10-9 to 3×10-8 M for bisphenol AF,and then the detection limit is 80 n M(3?/S).The sensor will lay the foundation for the further development of potential determination of inorganic ions and electrically neutral organic molecules.