水稻白叶枯病菌生理小种在纳米银膜上的表面增强拉曼光谱初探

SERS Spectra of Xanthomonas Oryzae pv.Oryzae(Xoo) on Nano Silver Film Prepared by Electrolysis Method

用硝酸银和聚乙烯醇混合溶液作为电解液,把载玻片放入电解液中,用银棒作为电极在直流电压下电解1 h,使载玻片在电解出的银胶中静置12 h后,取出晾干,即得制备的银膜。用便携式拉曼光谱仪测得在银膜上的白叶枯病菌7个生理小种的表面增强拉曼光谱(SERS)。7个生理小种分别是1-YN1,2-YN7,3-YN11,4-GD414,5-SCYC6,6-HEN11,7-FWJ,7个生理小种的SERS谱在峰位及峰的相对强度上都有很多差别。这可用于生理小种的鉴别。因为银膜上的纳米银颗粒是银胶中银颗粒的聚合体,这种聚合体大大缩小了纳米银之间的距离,从而产生了很强的电磁增强作用。电解法制备的银膜价格低廉,增强效果好,普通实验室便可以制备。此研究为快速、方便检测白叶枯病菌不同生理小种提出了一种新的方法,对白叶枯病的防治具有重要的意义。

The nano silver film was prepared by electrolysis method using silver nitrate and polyvinyl alcohol （PVA） in deionized water as the electrolyte, with four glass slides put in the electrolyte and two silver rods dipped into the electrolyte as the anode and cathode. A direct current was applied to the rods, then the four glass slides stayed in the silver colloids. Thus the authors got ~he nano silver film. Transmission electron microscopy （TEM） and scanning electron microscopy （SEM） were employed to detect the silver particles in the silver colloids and on the nano silver film. From the SEM we can see that the silver particles on the film formed different laycrs. In one layer, the distance between two particles was about 100 nm The samples of Xan- thomonas oryzae pv. Oryzae （Xoo） were 7 different kinds of bacterial blight, namely 1-YN1, 2-YN7, 3-YN11, 4-GD414, 5- SCYC6, 6-HEN11 and 7-FWJ. Because the silver particles in the colloids were aggregated on the film, there was large electro magnetic potentiation. So the SERS spectra of Xoo were perfect. The authors used the area analytical method to distinguish the different kinds of Xoo. The silver film prepared by electrolysis was cheap and active, the preparation time of the samples was short, and any normal chemistry lab can make it, which can find excellent application to detecting the Xoo in agriculture. On the mher hand, this film is active on biomolecules and bioorganism, which may be a new kind of SERS fundus to explain the creation of the SERS. Further study was under way.