Fabrication And Analytical Application Of Dissolved Oxygen Biosensors

Chapter 1: Biosensors are analytical devices composed of a recognition element of biological origin and a physico-chemical transducer. The biological element is capable of sensing the presence, activity or concentration of a chemical analyte in solution. The conception, basal constitution, principles, types, characteristic and research status of biosensors are reviewed.Chapter 2: A glucose biosensor using an enzyme-immobilized eggshell membrane and oxygen electrode for glucose determination has been fabricated. Glucose oxidase was covalently immobilized on an eggshell membrane with glutaraldehyde as a cross-linking agent. The glucose biosensor was fabricated by positioning the enzyme-immobilized eggshell membrane on the surface of a dissolved oxygen sensor. The detection scheme was based on the depletion of dissolved oxygen content upon exposure to glucose solution and the decrease in the oxygen level was monitored and related to the glucose concentration. The effect of glutaraldehyde concentration, pH, phosphate buffer concentration and temperature on the response of the glucose biosensor has been studied in detail. Common matrix interferents did not give significant interference. The resulting sensor exhibited a fast response, high sensitivity and good storage stability. The linear response is 1.0×10^-5—1.3 × 10^-3 mol/L glucose. The glucose content in real samples was determined, and the results were comparable to the values obtained from a commercial glucose assay kit based on a spectrophotometric method.Chapter 3: A biosensor for determination of glucosinolates has been fabricated by employing a bienzyme system composed of myrosinase and glucose oxidase immobilized onto an eggshell membrane and a dissolved oxygen electrode as the transducer. The detection scheme was based on the...