PNA-DNA hybridization study using labeled streptavidin by voltammetry and surface plasmon fluorescence spectroscopy.
Using ferrocene-streptavidin conjugates as amplifiers, we recently have demonstrated the simultaneous detection of DNA hybridization to peptide nucleic acid (PNA)-modified gold surfaces at the femtomole level by electrochemical and surface plasmon resonance techniques (Liu, J.; Tian, S.; Tiefenauer, L.; Nielsen, P. E.; Knoll, W. Anal. Chem. 2005, 77, 2756-2761). In this paper, a detailed study of the binding behavior of PNA-DNA is presented by square wave voltammetry and surface plasmon field-enhanced fluorescence spectroscopy (SPFS). The different binding constants for fully matched and single-mismatched DNA were obtained. The effect of the buffer concentration on the PNA-DNA hybrids was investigated using labeled streptavidin by cyclic voltammetry (CV) and SPFS. At high ionic strength, both the CV and SPFS signals were restrained dramatically, which is most probably due to a conformational change of the short-strand PNA-DNA helices on the surface. We conclude that the combination of electrochemical techniques with SPFS is very useful for the study of short DNA structure transformation.
Liu
Jianyun
J
Max-Planck-Institute for Polymer Research, Ackermannweg 10, D-55128, Mainz, Germany. jyliu26@yahoo.com
Tiefenauer
Louis
L
Tian
Shengjun
S
Nielsen
Peter Eigil
PE
Knoll
Wolfgang
W
D004247:DNA / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry; D009693:Nucleic Acid Hybridization / Q000379:methods*; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D011199:Potentiometry; D013050:Spectrometry, Fluorescence; D019809:Streptavidin / Q000737:chemistry*; D020349:Surface Plasmon Resonance
D005456:Fluorescent Dyes; D020135:Peptide Nucleic Acids; D004247:DNA; D019809:Streptavidin