The mechanism of nitric oxide release through gold nanoparticles-mediated catalytic decomposition of S-nitrosothiols by density functional theory

First principles calculations were performed to study the mechanism of nitric oxide release through the catalytic decomposition of S-nitrosothiols mediated by gold nanoparticles within the density functional theory. The gold nanoparticles and S-nitrosothiols were modeled by Au₃₈ cluster and SPEN compound, respectively. The results reveals a two-step reaction process. The primary step is SPEN adsorbs on Au₃₈ cluster surface by S atom to form the intermediate. In the next step, NO dissociates from SPEN under the catalysis of Au₃₈ cluster and thereafter a specie of Au-thiolate complex was produced as the product. Furthermore, we found that the overall catalytic reaction is exothermic with a small energy barrier, which confirms the reaction process is kinetically feasible. (paper)