engleski

Potential Induced Desorption, Adsorption and Real Time Monitoring of Organised Phospholipid Structures on Mercury Electrodes

Dioleoly-phospholipid molecules possess an amphiphilic character that enables their self assembly into ordered and yet mobile structures. These molecules can be directed to self-assemble onto a mercury surface under potential control to form monolayers with the phopholipid head groups orientated towards the electrolyte and the tail groups adsorbed onto the metal surface. Such surfaces resemble one half of a simplified biological membrane and represent a functional model that is capable of providing information on potentially toxic compounds that interact with biological membranes. Interactions with such compounds are observed by changes in the electrode capacitance that can be recorded in real-time using rapid cyclic voltammetry. By changing the electrode potential and thus surface charge density such adsorbed layers are motivated to undergo structural changes followed by desorption at extremes of potential. These structural changes are exhibited as electrical current peaks that occur at specific potentials and possess well defined spreads and magnitudes that are indicative of the adsorbed layer composition (Figure 1). These processes have been investigated on microfabricated mercury film electrodes with adsorbed layers of dioleoyl-sn-glycero-3-phosphocholine (DOPC) using rapid cyclic voltammetry and DC pulse techniques with attempts being made to image such surfaces with atomic force microscopy.

Desorption; /Adsorption; real time; Phospholipids; Mercury Electrode

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