Implantable wireless enzyme biosensor for monitoring of physiological states in Streptococcus iniae infected Tilapia

• Main Authors: Chen, Wei-Hung, 陳威宏
• Other Authors: Huang, Shih-Hao
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/d842x9

碩士 === 國立臺灣海洋大學 === 機械與機電工程學系 === 106 === Tilapia, an economically important cultured fish in Taiwan, plays a significant role in the fisheries development. It has less tolerable attributes of cold in winter and common bacterial infections in summer. Measurements of the variation of fish blood glucose and lactate concentration is a useful index to observe the change of physiological conditions. In this study, we adopted enzyme method to developed enzymatic biofuel cells and mediator-type biosensor. Enzymatic biofuel cell that consists of a needle bioanode used for glucose dehydrogenase (GDH) and a gas-diffusion biocathode used for bilirubin oxidase (BOD). The assembled device for glucose oxidation was inserted into Tilapia, producing maximum current density 41 (µA/cm^2),open voltage 0.41V, maximum power density 6.3(µW/cm^2) at 22℃ and maximum current density 52 (µA/cm^2), maximum power density 8.6(µW/cm^2) at 15℃ in free-swimming fish in the aquarium. We developed a wireless biosensor system to monitor glucose and lactate concentration in Tilapia. The biosensor was used Pt-Ir wire as the working electrode and Ag/AgCl as the reference electrode. Glucose dehydrogenase and lactate oxidase were immobilized on the working electrode to be glucose biosensor and lactate biosensor respectively. The sensor was inserted into Tilapia in order to wirelessly monitor the glucose and lactate concentration in free-swimming fish.We confirmed that blood glucose levels increased from 40mg/dl to 90mg/dl and lactate levels decreased from 20mg/dl to 10mg/dl in the blood when the temperatures dropped from 20℃to 15℃ in the aquarium. We also monitored the concentrations of glucose and lactate in Tilapia when it was infected by Streptococcosis. The results confirmed that blood glucose concentration increased from 41mg/dl to 92mg/dl and lactate concentration increased from 20mg/dl to 39mg/dl in the blood. The concentration from the sensor gradually increased and decreased during the application of stress, which hinted that the stress was monitored by this system. Keywords: Tilapia, Glucose enzyme, Lactate enzyme, Blood, Streptococcosis , Electrochemical analyzer , Wireless potential