Molecularly Imprinted Polymers For Determination Of Bovine Serum Albumin Based Surface Plasmon Resonance Biosensor

Bovine serum protein(BSA)is the most prevalent proteins present in bovine plasma and has widespread applications in the biological medicine.Currently,the reported methods for BSA detection include high performance liquid chromatography,fluorescence resonance energy transfer technology,capillary electrophoresis,enzyme-linked immunosorbent assay and surface plasmon resonance technology,etc.Among these methods,SPR plays an important role in the detection of proteins due to its label-free,real-time measurement,high selectivity,high sensitivity,and short analysis time.However,SPR biosensors require the implementation of biological antibodies as recognition elements,which are unstable and expensive.In this paper,molecularly imprinted polymers(MIP)were prepared as recognition elements for SPR detection of BSA.Bovine serum albumin(BSA)was chosen as the template,dopamine(DA)was used as the functional monomer and cross-linker and sodium periodate(SP)was used as the oxidant to prepare BSA molecularly imprinted polymer(MIP)surface plasmon resonance(SPR)biosensors.BSA molecules were fixed in advance through hydrogen bond via indroducing poly(acrylic acid)(PAA-SH)to increase recognition sites,and partially hydrolyzed poly(2-methyl-2-oxazoline)(PMOXA-EI)was also introduced into the noncavity regions to resist nonspecific adsorption of proteins.The prepared BSA-MIP SPR biosensor was characterized by X-ray photoelectron spectroscopy,atomic force microscopy,variable angle spectroscopic ellipsometry,and static water contact angle.SPR adsorption studies were carried out in aqueous BSA solutions with the concentration of 0.1～10 μg/mL.The limit of quantification and the limit of detection values were obtained as 161 ng/mL and 53 ng/mL,respectively.Selectivity studies were performed against β-lactoglobulin,ovalbumin,lysozyme,and cytochrome C,and the corresponding selectivity coefficients were determined to be 4.43,3.45,3.17 and 3.64,respectively.Furthermore,the BSA-MIP biosensor exhibited favorable reproducibility based on 6 cycles of equilibrium-adsorption-regeneration experiments,with relative standard deviation(RSD)of merely 6.2%.The preparation of five biosensors utilizing the same methodology exhibited exceptional reproducibility,with RSD of only 2.7%.Finally,BSA-MIP biosensor was used to detect BSA in the mixture solution of above five proteins.The recovery of BSA was 97.5～102.5%.