Development of needle-type biosensor system for monitoring of fish health

点击翻译按钮获取中文摘要

Mass outbreaks of pathogenic bacterial infections have killed large quantities of fish in recent years, causing great financial damage to fish farms. Periodic checks of fish health and detection of abnormalities as quickly as possible are thus necessary at fish farms. Several studies have shown blood glucose levels closely correlate to the level of stress in fish and represent the state of respiratory or nutritional disturbance. Recent studies have also clarified that decreased levels of blood cholesterol represent a useful indicator of reduced resistance to bacterial infection. In this manner, determination of blood glucose and cholesterol is important for ascertaining the health of fish. A needle-type biosensor system was developed for rapid and simple determination of glucose levels in fish blood. The sensor comprises a needle-type hollow container (18-gauge needle), immobilized enzyme membrane and optic fiber probe with ruthenium complex. The enzyme membrane was prepared from glucose oxidase, azide-unit pendant water-soluble photopolymer and an ultra-thin dialysis membrane. The optic fiber probe was inserted into the rolled enzyme membrane placed in the needle-type hollow container. The calibration curve was linear for glucose levels in fish plasma. One assay was completed within 3 min. A good reproducibility was observed for 60 times without exchange of the enzyme membrane. The sensor was inserted into the caudal vein of fish to measure blood glucose levels. The sensor responded immediately after insertion and glucose levels could be monitored. Good correlations were observed between values determined using the sensor and conventional methods in the range of 48-157 mg d1-1 (correlation coefficient, 0.9474).