Amperometric determination of choline with enzyme immobilized in a hybrid mesoporous membrane

Choline sensor is successfully prepared by using immobilized enzyme, i.e., choline oxidase (ChOx) within a hybrid mesoporous membrane with 12 nm pore diameter (F127M). The measurement was based on the detection of hydrogen peroxide, which is the co-product of the enzymatic choline oxidation. The determination range and the response time are 5.0-800 microM and approximately 2 min, respectively. The sensor is very stable compared to the native enzyme sensor and 85% of the initial response was maintained even after storage for 80 days. These results indicate that ChOx is successfully immobilized and well stabilized, and at the same time, enzyme reaction proceeds efficiently. Such ability of hybrid mesoporous membrane F127M suggests great promise for effective immobilization of enzyme useful for electrochemical biosensors.