A highly sensitive ethanol biosensor based on A. aceti biofilm, which contains PQQ-ADH enzyme for halal detection in food and beverages has been developed. In this study, before the biosensor construction, A. aceti cells were purified by determining the conditions of growth time, incubation temperature and pH to suppress yeast growth as contaminants. Selection of optimum conditions for biofilm formation was also carried out to obtain a stable sensor operation. The optimum biofilm formation was 14 days. The performance of biosensor was investigated by the cyclic voltammetry technique. Linear range, sensitivity, limit of detection and limit of quantification were found to be 5 x 10^-5 3 x 10^-4 %, 43076 µA %^-1, 2.32 x 10^-5 and 7.03 x 10^-5 % , respectively. The repeatability of biosensor was tested in 1 x 10^-5 1 % ethanol concentration and the resulted relative standard deviation (RSD) was 1.08 % (for n = 7).The stability studies have shown that the cyclic voltammetry response of biosensor to ethanol leave the act of 98.99 % at the 7 weeks. Thus, the developed biosensor is promising to be used for simple analysis of halal products and has been tested on real sample.
Key words: Biosensors, Ethanol, A. aceti, biofilm, PQQ-ADH, Halal
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