利用简单的湿化学方法制备出多刺状的银@金和银@金@银纳米结构作为高活性的表面增强拉曼散射(SERS)基底.使用不同形状的银纳米结构(纳米球、纳米棒和纳米片片)作为前躯体来合成银@金和银@金@银纳米结构,其形状相似但具有不同刺状表面的两种纳米材料.它们的形貌、组成、光学性质和SERS活性分别用过扫描电镜、元素分析、紫外可见吸收光谱和拉曼光谱进行表征.这些刺状结构在可见光区域具有宽的较强的吸收峰且具有较高的SERS活性.用结晶紫(CV)作为探针分子,所有不同形貌的刺状银@金@银复合物比相应银@金结构的S阻S信号大大提高.在这些纳米材料中,以纳米球为前躯体的刺状的银@金@银纳米球具有最强的增强能力,用SERS来检测CV时的最低检测浓度为1x10-10moVL.该合成方法具有成本低廉,操作简单,产率高等优点,可以用来制备各种刺状的金、银结构，在SERS 、催化、光学等等领域具有更好的应用前景.%A general,robust but simple wet-chemical approach is proposed to prepare spinous silver@gold (Ag@Au) or silver@gold@silver (Ag@Au@Ag) nanostructures as highly active substrates for surface enhanced Raman scattering(SERS).Using silver nanostructures with different shapes (nanospheres,nanorods,or nanosheets) as precursors,Ag@Au or Ag@Au@Ag with similar shape to precursors but with a spiny surface can be facilely prepared.The morphology,component,optical properties and SERS activity of these spiny products were investigated by SEM,EDS,UV-vis absorption,and Raman spectra.These spinous products display a broad and enhanced absorption spectrum in the visible light region,and a high enhancement ability as SERS substrates.For probing crystal violet (CV),all spiny Ag@Au@Ag with different shapes display much stronger SERS signal than those of corresponding silver precursors.Among these products,the spiny Ag@Au@Ag with spherical shape shows the highest enhancement ability,on which the lowest SERS detectable concentration of CV can be down to 0.1 nmol/L.The proposed method with low cost,simple operation,and high-yield can be used to prepare various spinous gold/silver structures,which have promising applications in SERS,catalysis,optics and so on.
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