Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (02): 397-402.doi: 10.3866/PKU.WHXB20100136

• PHOTOCHEMISTRY AND SPECTROSCOPY • Previous Articles     Next Articles

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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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