Preparation,Characterization And Analytical Application Of Bisphenol A And Kanamycin Molecularly Imprinted SPR Sensors

As a booming technique, molecular imprinting has attracted extensive attention. In the existence of cross-linking agent and initiator, the template molecule and functional monomer react to form a rigid polymer with the specific binding sites. Because of the advantages of high chemical stability, simple preparation, recycling, low costs and so on, MIPs have been widely used in various fields.Surface plasmon resonance(SPR) is associated with the evanescent electromagnetic field generated on the surface of a thin metal film when excited by an incident beam of light of appropriate wavelength at a particular angle. When a surface immobilized recognition film binds to an analyte, the change in the interfacial refractive index can be detected as a shift in the SPR wavenumber at SPR angle. Lots of chemosensors and biosensors based on SPR have been developed due to the properties of simplicity, speed, no labeling and high-sensitivity. For the past few years, SPR has been used in food security, environmental monitoring, pharmaceutical analysis and so on.In this paper, with the combination of molecular imprinting and surface plasmon resonance, two SPR sensors were prepared. The molecular interaction of the functional monomer 4-vinyl pyridine with the template bisphenol A was analysed by spectrophotometric method. On that basis, a bisphenol A imprinted membrane on the surface of a surface plasmon resonance chip was assembled using 4-vinyl pyridine as the functional monomer, ethylene glycol dimethacrylate as the cross-linking agent, and azodiisobutyronitrile as the initiator. The adsorptivity and selectivity of the imprinted film to bisphenol A were evaluated at optimum pH. The imprinted sensor had a better imprinting effect and higher selectivity for bisphenol A than the non-imprinted one. The linear range of imprinted sensor for bisphenol A was from 1.0×10-8 to 1.0×10-6 mol/L(R2 = 0.9902). Based on a signal-to-noise ratio of 3, the detection limits of bisphenol A were 6.15×10-9 mol/L for the bottled water and 6.84×10-9 mol/L for the polycarbonate water bottle, which showed good sensitivity. The combination of surface plasmon resonance sensing with imprinted film is a promising alternative method for detection of bisphenol A.A kanamycin molecular imprinted SPR sensor was prepared with 4-vinylbenzeneboronic acid as the functional monomer, polyethylene glycol acrylate and 2,2’-azo isobutyl amidine hydrochloride as the cross-linking agent and the initiator, respectively. The adsorptivity and selectivity of the imprinted film to kanamycin were evaluated at optimum pH. The imprinted sensor had a better imprinting effect and higher selectivity for kanamycin than the non-imprinted one. The linear range of imprinted sensor for bisphenol A was from 1.0×10-7 to 1.0×10-5 mol/L(R2 = 0.9941). Based on a signal-to-noise ratio of 3, the detection limits of kanamycin were 4.33×10-8 mol/L for milk powder and 1.20×10-8 mol/L for honey, with the RSD as 1.18% and 0.31%, respectively.