Development of the bacteria and plant tissue-based biosensor for determination of phenolic compounds

In this study, biosensors have been developed for the detection of phenolic compounds in various samples using corn tassel, pepper seed and Pseudomonas putida isolated from Batman South Raman, which showed polyphenoloxidase enzyme activity using phenolic compounds as substrate. For this purpose, polyphenol oxidase enzyme activities of the crude enzyme extracts of corn tassel, pepper seed and Pseudomonas putida were determined in the presence of 0.1 M catechol by spectrophotometric method. To develop biosensors, plant tissues and bacteria were immobilized onto oxygen electrode using gelatin as the immobilization material and glutaraldehyde as the crosslinker. The effect of temperature and pH on the biosensor responses of the prepared biosensors were determined and the effect of corn tassel, pepper seed and bacteria, glutaraldehyde and gelatin amount on the biosensor were examined. The linear range of the catechol used as a substrate was determined by the biosensors prepared, the reproducibility of the results, storage stability, interference effect of some chemicals and the applicability of biosensors in the determination of phenolic compounds in real samples were examined. In the studies, the optimum pH of the biosensor prepared with corn tassel homoganete was 7.0 and the optimum temperature was 40 ºC.In optimization studies of bioactive layer components; The most suitable tissue amount was 100 mg, the most suitable gelatin amount was 10 mg and the most suitable glutaraldehyde percentage was determined as 1.5%.The linear range for catechol, which is the most suitable substrate of plant tissue-based biosensor prepared under optimum conditions, was determined as 0.05-0.2 M. In order to determine the stability and reproducibility of the biosensor, measurements were carried out 6 times at 30 min intervals. In determination of storage stability of biosensor; measurements were performed at different intervals for 30 days. It was determined that the activity continued for the first 20 days. It was found that zinc had the most interference effect. Phenol analysis of apple juice and waste water samples nearby copper mining field in Maden town of Elazığ city. The optimum pH of the biosensor prepared with pepper seed homogenate was 7.0 and the optimum temperature was 40 ºC. In optimization studies of bioactive layer components; The most suitable tissue amount was 100 mg, the most suitable gelatin amount was 10 mg and the most suitable glutaraldehyde percentage was determined as 1%. The linear range for catechol, which is the most suitable substrate of plant tissue-based biosensor prepared under optimum conditions, was determined as 0.1 –0.2 M. In order to determine the stability and reproducibility of the biosensor, measurements were carried out 6 times at 30 min intervals. In determination of storage stability of biosensor; Measurements were performed at different intervals for 35 days. It was determined that the activity continued for the first 30 days. It was determined that zinc and manganese had the most interference effects. Phenol analysis of apple juice and waste water samples nearby copper mining field in Maden town of Elazığ city. The optimum pH of the biosensor prepared with the bacteria was 7.0 and the optimum temperature was determined as 30 ºC. The optimum extract amount was 100 mg, the optimum gelatin amount was 5 mg and the optimum glutaraldehyde percentage was 1.5%. . The linear range for catechol, which is the most suitable substrate of bacterial-based biosensor prepared under optimum conditions, was determined as 0.1 –0.4 M. In order to determine the stability and reproducibility of the biosensor prepared with bacterial homogenate, measurements were carried out 5 times at 30 min intervals. In determination of storage stability of biosensor; Measurements were performed for 30 days. It was determined that the activity continued during the first 30 days. When the interference effect of some chemicals was examined, it was found that nickel had the most interference effect. Phenol analysis of apple juice and waste water samples nearby copper mining field in Maden town of Elazığ city.