物理化学学报 >> 2010, Vol. 26 >> Issue (02): 397-402.doi: 10.3866/PKU.WHXB20100136

光化学与光谱 上一篇    下一篇

DNA碱基与高氯酸根共吸附行为的表面增强拉曼光谱研究

崔丽, 任斌, 田中群   

  1. 中国科学院城市环境研究所, 福建 厦门 361021; 厦门大学化学化工学院化学系, 固体表面物理化学国家重点实验室, 福建 厦门 361005
  • 收稿日期:2009-08-12 修回日期:2009-09-23 发布日期:2010-01-26
  • 通讯作者: 崔丽, 任斌 E-mail:bren@xmu.edu.cn; lcui@iue.ac.cn

Surface-Enhanced Raman Spectroscopic Study on the Co-adsorption of DNA Bases with Perchlorate

CUI Li, REN Bin, TIAN Zhong-Qun   

  1. Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, Fujian Province, P. R. China; State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian Province, P. R. China
  • Received:2009-08-12 Revised:2009-09-23 Published:2010-01-26
  • Contact: CUI Li, REN Bin E-mail:bren@xmu.edu.cn; lcui@iue.ac.cn

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摘要：

共吸附有助于实现弱吸附分子或离子的高灵敏表面增强拉曼光谱(SERS)检测. 本文研究了四种脱氧核糖核酸(DNA)碱基, 即腺嘌呤、鸟嘌呤、胞嘧啶、胸腺嘧啶与高氯酸根(ClO-4)在金纳米粒子表面的共吸附行为, 并考察了吸附能力、电位、共存阴离子等因素的影响. 研究发现四种碱基在质子化后都可以与ClO-4发生共吸附, 但在金表面吸附能力弱的胸腺嘧啶与ClO-4共吸附所获得的ClO-4信号最弱. 另外, 负电位下电极的排斥作用, 以及较正电位下基底SERS增强效应减小等因素都会导致ClO-4信号衰减. 此外, Cl-、NO-3、SO2-4等阴离子可以与ClO-4发生可逆动态竞争共吸附, 同时引起ClO-4信号减弱. 以上结果将为提高共吸附法检测弱吸附离子的灵敏度提供重要参考.

关键词: 共吸附, 表面增强拉曼光谱, DNA碱基, 高氯酸根

Abstract:

Co-adsorption with molecules that strongly adsorb on metallic surfaces is beneficial in improving the surface-enhanced Raman spectroscopy (SERS) detection sensitivity of some weakly adsorbed molecules or ions. In this paper, the co-adsorption of four deoxyribonucleic acid (DNA) bases: adenine, guanine, cytosine, and thymine with ClO-4 was studied. Factors like adsorption ability, applied potentials, and coexisting anions were examined to illustrate how they affect co-adsorption. We found that the four DNA bases in their protonated forms could co-adsorb with ClO-4. Among them, thymine with the weakest adsorption ability on Au showed the weakest co-adsorption ability with ClO-4. In addition, repulsion from both negative potentials and reduced SERS enhancements of Au substrates at relatively positive potentials led to a decrease in the SERS intensity of ClO-4. Moreover, anions such as Cl-, NO-3 , and SO2-4 were shown to influence the co-adsorption of ClO-4 with adenine based on a dynamic and reversible competitive co-adsorption process. The above results are very helpful in optimizing the SERS detection sensitivity of weakly adsorbed ions or molecules via the co-adsorption method.

Key words: Co-adsorption, Surface-enhanced Raman spectroscopy, DNA bases, ClO-4