Europium tetracycline biosensor for the determination of cholesterol

Abstract

Development of cholesterol biosensors is of great importance in clinical analysis because the concentration of cholesterol in blood is a fundamental parameter for the prevention and diagnosis of a number of clinical disorders such as heart disease, hypertension and arteriosclerosis. In general, determination of cholesterol is based on spectrophotometry; but this method involves complicated procedures and the cost is high because expensive enzyme must be used in each assay. We report here the observation, for the first time, of the enhancement of Europium-Tetracycline complex emission in cholesterol solutions. This enhancement was initially observed with the addition of the enzyme cholesterol oxidase, which produces H2O2, the agent driver of the Europium tetracycline complex, to the solution. However, it was found that the enzyme is not needed to enhance the luminescence. A calibration curve was determined, resulting in an easy-handling immobilization method with a cheap stable material. This method shows that the complex can be used as a sensor to determine cholesterol in biological systems with good selectivity, fast response, miniature size, and reproducible results.