Stable, colourless and water-soluble electron-transfer mediators used in enzyme electrochemistry

作者：Vuorilehto K^*

来源：Journal of Applied Electrochemistry, 2008, 38(10): 1427-1433.

DOI：10.1007/s10800-008-9587-2

• colourless
• complex ion
• redox enzyme
• indirect electrochemistry
• mediator
• redox titration

Electron-transfer mediators are needed to transport charge between electrodes and enzymes, as enzymes hardly react on conventional electrode surfaces. Several complex ions were tested for their stability, absorbance and ability to work as electron-transfer mediators. A set of five stable mediators covering the potential range from 0 mV to +800 mV vs. SHE was established: [Fe-DCTA](0/1+) (DCTA is 1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid), [Co-terpyridine(2)](2+/3+), [Fe(CN)(6)](4-/3-), [W(CN)(8)](4-/3-) and [Mo(CN)(8)](4-/3-). These mediators are water-soluble, pH-independent and able to transfer one electron at a time. This set offers promising mediator candidates whenever indirect electrochemistry is needed, as is not restricted to any particular enzyme. It is especially useful for redox titrations and other enzyme research, where colourlessness is required. As all charge is consumed by the desired redox reactions, and not by degradation reactions, even amperometric and coulometric titrations are possible.

• 出版日期2008-10