Adsorption of bovine serum albumin (BSA) on polystyrene (PS) and its acid copolymer |
| |
Authors: | Thidarat Wangkam Sirasa Yodmongkol Jarupat Disrattakit Boonsong SutapunRathasart Amarit Armote SomboonkaewToemsak Srikhirin |
| |
Institution: | a Center of Intelligence Materials and Systems, NANOTEC Center of Excellence at Mahidol University, Thailand b Materials Science and Engineering Programme, Thailand c Physics Department, Faculty of Science, Mahidol University, Bangkok 10400, Thailand d Photonics Technology Laboratory, National Electronics and Computer Technology Center (NECTEC), Pathumthani 12120, Thailand |
| |
Abstract: | The effect of surface polarity on the adsorption of bovine serum albumin (BSA) on polystyrene (PS), 7% polystyrene-co-maleic anhydride (7%PSMAn) and 50% polystyrene-co-maleic acid (50%PSMA), at pH 7.4, was investigated. Polystyrene represented the non-polar surface while 7%PSMAn and 50%PSMA represented a low and high acid content copolymer. The amount of the adsorbed BSA depended on the amount of the acid content in the copolymer. BSA formed a monolayer with a side-on orientation on the low polarity PS surface, a mixed side-on and end-on orientation on 7%PSMAn and a predominantly side-on orientation on 50%PSMA. The thickness of adsorbed BSA, measured with an atomic force microscope (AFM), varied from 3 nm to 5 nm for the side-on orientation and from 10 nm to 15 nm for the end-on orientation. The average area occupied per BSA molecule was consistent with the proposed orientation, and was 34.8 nm2, 27.8 nm2 and 18.0 nm2 for PS, 7%PSMAn and 50%PSMA, respectively. The adsorption showed a concentration dependency following the Freundlich isotherm, which indicated the interactions among adsorbed BSA molecules on the polymer surface. The adsorption took place as an island-like morphology and started to fuse into a patch-like morphology at higher concentrations before achieving a complete monolayer formation. A non-uniform surface coverage and defects were observed in all cases. It is recommended that for an effective blocking of PS, 7%PSMAn and 50%PSMA, the BSA concentration should be higher than 3 mg/mL. |
| |
Keywords: | Surface plasmon resonance Bovine serum albumin Monolayer Surface blocking |
本文献已被 ScienceDirect 等数据库收录! |
|