Glucose polymer protocol

In this paper, we have evaluated three different protocols for the preparation of AQ-enzyme film using choline and glucose oxidases and mixture of AQ 29D and AQ 55D (1 1). This AQ mixture is recommended by Eastman Kodak to increase the adherency of the film to a surface such as a platinum electrode (17). The values 29 and 55 represent the glass transition temperature of each polymer. Also, the main structural difference between the two polymers is that, in the case of AQ 55D, an aliphatic glycol moiety replaces the cycloaliphatic glycol moiety found in the AQ29 (17,18). 

Film Fabrication. The platinum electrode (0.28 cm area) was fabricated and cleaned as previously described (19). Thin films of AQ-enzyme were prepared by dissolving an amount of the enzyme, as indicated below, in 10 il of 1.5% AQ polymers solution at room temperature. Two aliquots of 5 il were deposited atop the platinum electrode and the first aliquot was allowed to dry before the second addition. This procedure corresponds to the first protocol. In addition, for the second protocol, 10 il of the 0.5% Nafion solution was casted atop the dried AQ-enzyme film and the methanol was allowed to evaporate at room temperature. The third protocol consisted in the deposition of 10 il of a 1% of AQ solution containing the enzyme, atop the platinum electrode followed by heating in an oven at 50°C during 30 min. In each case, 2 U of glucose oxidase were used. 

D. Modified Semi-Quantitative Solid Surface Studies. The ASTM protocol for polymer biodegradation by fungus was modified for the studies involving the zinc chloride-containing polymer matrices. Zinc chloride (10% w/w) was dissolved in 2 mL acetone and added to the polymer solutions. Films were cast on the bottom of sterile petri dishes and the solvent allowed to evaporate. Warm glucose supplemented (1% w/w) BMS-agar (20 mL) was inoculated with 0.1 mL of the spore suspension and then poured over the surface of each polymer film. The plates were incubated at room temperature for two to four weeks after which the effect of the zinc on microbial growth was visually observed. 

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