In this work, the adsorption of protein on Au surface coated by self-assembled monolayers (SAMs) of alkanethiol chains is studied by molecular dynamics simulations with an all-atom model. Particularly, a more realistic embedded-atom method potential has been used to characterize the Au-Au interactions in the system as compared to previous studies. With this all-atom model, many experimental observations have been reproduced from the simulations. It is found that the SAMs have the lowest adsorption energy on Au (111) surface where the alkanethiol chains form a well-ordered (√3x√3) R30° triangular lattice at 300 K. Furthermore, it is confirmed that carboxyl-terminated SAMs are more effective to absorb proteins than the methyl-terminated SAMs. Base on the simulation results, we propose that the experimentally observed aggregation of protein-Au nanoparticle conjugates is mainly due to the electrostatic interactions between protein amino acids and carboxyl-terminated SAMs from multiple Au surfaces. / October 2016
| Identifer | oai:union.ndltd.org:MANITOBA/oai:mspace.lib.umanitoba.ca:1993/31807 |
| Date | 27 May 2016 |
| Creators | Wei, Aoran |
| Contributors | Deng, Chuang (Mechanical Engineering), Xing, Malcolm (Mechanical Engineering) Budzelaar, Peter (Chemistry) |
| Publisher | The Journal of Physical Chemistry C |
| Source Sets | University of Manitoba Canada |
| Detected Language | English |
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