Chemiluminescence flow biosensor system for cholesterol with immobilized reagents

A chemiluminescence biosensor combined with flow injection analysis has been developed for determining cholesterol. Cholesterol oxidase was immobilized onto amine-modified silica gel via glutaraldehyde activation and packed in a column. The analytical reagents, including luminol and ferricyanide, were electrostatically coimmobilized on an anion-exchange column. Cholesterol was sensed by the CL reaction between hydrogen peroxide released from the enzymatic reaction and luminol and ferricyanide, which were released from a column with immobilized reagents by elution. The calibration graph was linear over the range 5x10-6 to 1x10-4 g ml-1 and the detection limit was 5x10-6 g ml-1. The proposed method has been successfully applied to the determination of cholesterol in human serum.