Effect of functionalization on stability, solubility, and plasmonic features of gold nanoparticle with the general formula of Au₁₈(SR)₁₄ in water solvent has been studied in this work. Thiol functional groups including 1,1-mercapto-ethyl alcohol, s-cysteamine, thioglycolic acid, and beta-mercaptoethanol have been used. Electronic band-gap, excitation energies, dipole moment, and hardness for all gold nanoparticles in water solvent were investigated using the quantum mechanical approach. Intermolecular forces, radial distribution function (RDF), mean square displacement (MSD), and solvation free energy were calculated by using simulation methods. Electronic band-gap, and excitation energy analysis show that surface modification of gold nanoparticles can change their electronic and plasmonic properties. The analysis of dipole moments indicates that ligands affect the nanoparticle’s solubility. An increase of hardness and therefore chemical stability can be observed for functionalized nanoparticles compared to the bare structure. Intermolecular energies analyses suggest that structure with 1,1-mercapto ethyl alcohol ligand has the strongest interaction with the solvent. The analysis of RDF diagrams also indicates that the molecule with 1,1-mercapto ethyl alcohol ligand has the sharpest pick. The slope of the linear part of MSD diagrams that is the criterion of solute’s lateral diffusion is the highest value for nanoparticle with 1,1-mercapto ethyl alcohol ligand. Furthermore, functionalization also affects solvation free energy contributions. According to obtained data of quantum mechanical calculations and molecular dynamics simulations, it may be concluded that particle with 1,1-mercapto ethyl alcohol is the best ligand for increasing solubility, stability, and plasmonic functions of Au₁₈(SR)₁₄ structures among the examined ones.

功能化对通式为Au ₁₈（SR）₁₄的金纳米粒子的稳定性，溶解度和等离子体特性的影响在这项工作中已经研究了在水中的溶剂。已经使用了包括1，1-巯基乙醇，s-半胱胺，巯基乙酸和β-巯基乙醇的硫醇官能团。使用量子力学方法研究了所有金纳米颗粒在水溶剂中的电子带隙，激发能，偶极矩和硬度。使用模拟方法计算分子间力，径向分布函数（RDF），均方位移（MSD）和溶剂化自由能。电子带隙和激发能分析表明，金纳米粒子的表面改性可以改变其电子和等离子体性能。偶极矩的分析表明，配体会影响纳米颗粒的溶解度。与裸露的结构相比，可以观察到官能化的纳米颗粒的硬度增加，因此化学稳定性提高。分子间能量分析表明，具有1,1-巯基乙醇配体的结构与溶剂的相互作用最强。对RDF图的分析还表明，具有1，1-巯基乙醇配体的分子具有最强的拾取性。MSD图的线性部分的斜率是溶质横向扩散的标准，是具有1,1-巯基乙醇配体的纳米颗粒的最大值。此外，官能化还影响溶剂化自由能的贡献。根据获得的量子力学计算和分子动力学模拟的数据，可以得出结论，具有1的粒子₁₈（SR）_14个结构在被检查的结构中。