Restructuring and cleaavage of ferrocene-alkanethiol ester SAMs in lipase-based activity assays.

Anders B. Olesen ,  Majken Hansen ,  Stepan Shipovskov ,  Duncan Sutherland ,  Kurt Gothelf ,  Elena E. Ferapontova 

University of Aarhus, Chemistry Department, Center for DNA Nanotechnology (CDNA), Langelandsgade 140, Aarhus 8000, Denmark


Electrochemical activity of ferrocene (Fc)-terminated SAM of alkane ester immobilised on gold electrode is shown to depend on the buffer conditions used. It is demonstrated that upon electrochemical activation in phosphate buffer solutions and further in sulphuric acid solutions the SAMs undergo restructuring, which stabilises the signal from the Fc groups and exposes the internal ester groups to the SAM/solution interface. The restructuring of the SAM enables efficient hydrolysis of the ester bond by lipase enzyme accompanied by the release of the part of the Fc redox active groups from the electrode surface, thus decreasing the electrochemical signal from the surface-confined Fc groups. This reaction was used in electrochemical sandwich DNA hybridisation assay with lipase as a label.


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Presentation: Poster at SMCBS'2009 International Workshop, by Anders B. Olesen
See On-line Journal of SMCBS'2009 International Workshop

Submitted: 2009-08-30 17:01
Revised:   2009-08-30 17:11