Preparation of Polymer Film Biosensors

Polymer film biosensors are formed by coating the electrode surface with preformed polymers or by in situ formation and deposition of polymer films on the 

Another method of casting preformed polymer films on electrode surface involves using droplet evaporation in a desiccator, open air, or with a heat gun cross-linking reagents, such as glutaraldehyde, are usually needed in this procedure. The advantage of this method is that the thickness of the film can be controlled through the amount of biosensor film solution deposited on the electrode surface. 

Electrochemical polymerization can be effected by potentiostatic, gal-vanostatic, or potentiodynamic (i.e., cyclic voltammetric) methods. In the gal-vanostatic mode, an amount of current is passed through the solution containing the monomer, and the polymer film is formed on the working electrode. In the potentiostatic mode the working electrode is kept at a potential at which polymerization takes place on the electrode. In the cyclic voltammetric method, the potential of the working electrode is scanned within a range determined by the oxidation potential of the polymer film. Potentiostatic and cyclic voltammetric formations of polymer films have wider applications in biosensor fabrication than the gal-vanostatic method.  

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