Detection of molecular interactions with modified ferrocene self-assembled monolayers

Area of Science:

• Electrochemistry
• Surface Science
• Molecular Recognition

Background:

• Ferrocene-terminated self-assembled monolayers (Fc-SAMs) are widely used for studying electron transfer.
• They offer a stable and reproducible platform for investigating microenvironmental effects on electrochemical parameters.

Purpose of the Study:

• To introduce a new application of Fc-SAMs for detecting molecular interactions.
• To demonstrate the modification of Fc-SAMs with target-specific receptors for sensing.

Main Methods:

• Fabrication of mixed self-assembled monolayers (SAMs) on gold electrodes.
• Co-immobilization of thiolated alkane chains with different head groups (hydroxy, ferrocene, biotin).
• Characterization using AC voltammetry and measurement of formal potential shifts.

Main Results:

• Binding of charged target molecules (e.g., streptavidin) to receptors on the SAM.
• Modification of the electrostatic potential at the electron transfer plane.
• Observable shifts in the formal potential (E°') upon target binding, dependent on pH.

Conclusions:

• Fc-SAMs functionalized with receptors can detect molecular interactions through electrochemical signal changes.
• The observed shifts in formal potential confirm the charge-based detection mechanism.
• This approach provides a sensitive method for molecular interaction analysis.