摘　要：为实现活性细菌的快速和原位检测，使用无机碱性双氧水作为“清洁”还原剂，还原制备了一种毛丹状Au@Ag合金纳米颗粒，并将其作为表面增强拉曼散射（SERS）基底材料。研究发现：构建的毛丹状Au@Ag合金纳米颗粒具有较高的表面粗糙度和致密的表面纳米毛刺，该结构对细菌表面的吸附能力较强，且不影响细菌的生物活性；构建的毛丹状Au@Ag合金纳米颗粒在单颗粒表面具有大量的“纳米针尖”和“纳米间隙”，这种结构可产生较强的局部表面等离子体共振效应；将毛丹状Au@Ag合金纳米颗粒吸附于细菌表面，可以有效地增加细菌表面的SERS“热点”，且在实际检测中容易操作。利用以上特点，在633 nm的激发光激发下，可以有效获得活性细菌的SERS指纹谱信号，该方法的灵敏度和检测效率高，能广泛应用于微生物细胞的SERS传感分析。
关键词：金纳米结构；局部表面等离子体共振；光激发及散射；细菌传感；SERS指纹谱信号
中图分类号：O657.37　　　　　　文献标志码： ADOI：10.3969/j.issn.1007-7146.2021.03.002

Abstract: In order to achieve rapid and in situ detection of active bacteria, inorganic alkaline hydrogen peroxide was used as a “clean” reducing agent to reduce and prepare a kind of rambutan-like Au@Ag alloy nanoparticles, which was used as surface enhanced Raman scattering (SERS) substrate material. The results showed that the constructed rambutan-like Au@Ag alloy nanoparticles had high surface roughness and dense surface nano burrs, and the structure had strong adsorption ability on the surface of bacteria, and did not affect the biological activity of bacteria. The rambutan-like Au@Ag alloy nanoparticles have large number of “nano-tip” and “nano-gap” on the surface of single particles, which can produce strong local surface plasmon resonance effect. The rambutan-like Au@Ag alloy nanoparticles are adsorbed on the bacterial surface, which could effectively increase the SERS “hot spots” on the bacterial surface, and it was easy to operate in the actual detection. Using the above characteristics, under the excitation of 633 nm light, the SERS fingerprint spectrum signals of active bacteria could be effectively obtained. With high sensitivity and efficiency of detection, it could be widely used in the SERS sensing analysis of microbial cells.
Key words: gold nanostructure; local surface plasmon resonance; light excitation and scattering; bacterial sensing of surface enhanced Raman scattering; SERS fingerprint signal
（Acta Laser Biology Sinica, 2021, 30(3): 200-206）