探討在陰離子界面活性劑中金奈米粒子的銀殼成長機制與這些金屬粒子的穩定性。我們以SDS-AuNPs做為晶種溶液，並加入硝酸銀與維生素C，然而銀離子不會被還原，而是分別吸附在SDS-AuNPs表面、SDS單體以及SDS微胞，導致SDS-AuNPs聚集。為了改善維生素C的還原能力，我們在溶液內添加NaOH，則銀殼會在金奈米粒子表面成長。此外，溶液內添加EDTA做為螯合劑，目的是為了避免SDS與銀離子產生交互作用，此作用會增加銀奈米粒子形成之機率。在SDS-AuNPs溶液內依序加入EDTA、NaOH、AgNO3與AA，再加入數次AgNO3與AA的方法，可以讓金核表面包覆的銀殼均勻度較佳。另一方面，若添加數次NaBH4至SDS-Au@AgNPs溶液內，銀殼會受到影響而分解。最後，SDS-AuNPs溶液內含銀離子莫爾數為2.54 x 10-7至25.4 x 10-7時，硝酸銀莫爾數與吸收波長470 nm的吸收強度成正比，可得到一檢量線，應用於偵測未知溶液內的銀離子濃度。 Mechnism of the growth of silver shells on the gold nanoparticles and the stability of these metal particles are studied in anionic surfactant solutions. Silver nitrate and ascorbic acid were added to the SDS-AuNPs seed solution. Silver ions were not reduced but adsorbed on SDS-AuNPs surfaces, the SDS monomer and SDS micelles, which led to the aggregation of SDS-AuNPs. To improve the reducing ability of ascorbic acid , NaOH was added and resulted in the growth of silver shells on the surface of AuNPs. Further, EDTA is used as the chelating agent to prevent the interaction of SDS and silver ions which could enhanced the probability of AgNPs formed in the solution. For coating a thicker layer of silver, EDTA solution, NaOH solution, silver nitrate solution and ascorbic acid solution were sequentially added to SDS-AuNPs solution at first. Then, the addition of silver nitrate solution and ascorbic acid solution were repeatedly followed. On the other hand, decomposition of the outer silver shell was observed when extra NaBH4 agents were added to SDS-Au@AgNPs solution. Finally, a calibration curve of silver is stablished in the range of 2.54 - 25.4 x 10-7 mole based on the inetnsity of th absorption peak at 470 nm, which could be applied to detect the concentration of silver ions in the unknown solution.