Publication details
OPTIMIZATION OF SARCOSINE OXIDASE BIOSENSOR FOR DETERMINATION CARBOXYLIC ACIDS IN REAL SAMPLES OF FRUIT WINE
| Authors | |
|---|---|
| Year of publication | 2014 |
| Type | Article in Proceedings |
| Conference | CECE 2014: 11TH INTERNATIONAL INTERDISCIPLINARY MEETING ON BIOANALYSIS |
| MU Faculty or unit | |
| Citation | |
| Keywords | ORGANIC-ACIDS; CAPILLARY-ELECTROPHORESIS |
| Description | The flow-through one-channel amperometric biosensor for monitoring of relative inhibition of sarcosine oxidase (SOX) was presented. Biosensor was based on two sensing layers deposited on a screen-printed platinum electrode. The inner layer eliminated interferences by limiting diffusion of electrochemically active substances such as ascorbic acid and polyphenols. This layer was formed by electropolymerization using the equimolar mixture of o-phenylenediamine and resorcinol in 2 mM or 4 mM concentration. The outer layer was prepared by crosslinking the enzyme SOX and bovine serum albumin (BSA) using glutaraldehyde (GA). The formation of enzymatically produced hydrogen peroxide was monitored at 650 mV vs. an Ag/AgCl reference electrode. The addition of carboxylic acids caused competitive reversible inhibition of the immobilized enzyme and a decrease in signal. The assay was optimized for determination of carboxylic acids in fruit wine samples. The 10-fold dilution of real samples and a 5 mM concentration of sarcosine was chosen as optimal for competition. In case of real samples, the biosensor measured the sum of all carboxylic acids, which served as a parameter describing the quality of fruit wines. Two types of fruit wines including bilberry and chokeberries were used for biosensor optimization. To better understand the influence of phenolic compounds during sample measurement, the solid phase extraction (SPE) for elimination of phenolic compounds was used. |