Enzyme biosensors based on carbon nanotubes applied for diabetes management

3-hydroxybutyrate dehydrogenase enzyme biosensor based on screen-printed electrode modified with single layer carbon nanotubes was designed by Iranian researchers to determine the concentration of 3-hydroxybutyrate (HB) in serum. Precise determination of 3-hydroxybutyrate in biological samples is vital for the management of diabetes. Concentration of 3-hydroxybutyrate is usually determined through methods such as chromatography, isotopic measurements, and spectrophotometry. These methods, however, are usually time-consuming and require a number of processing stages. They also need specific equipment and detectors, and large number of professional experts. Dr. Kobra Omidfar, one of the executors of the plan, stated, “In this study, a simple method was presented to fabricate hydroxybutyrate (HB) biosensor by using single layer carbon nanotubes. The use of carbon nanotubes decreases the oxidation potential of NADH to -0.05 V, which is desirable for electrochemical detection.” The reason for the decrease in NADH potential can be explained by the use of nanotechnology and nanomaterials. Nanomaterials are used in the design of biosensors and various immunological detection methods due to their capacity in increasing stability and sensitivity in addition to improving the efficiency. Carbon nanotubes (CNTs) are considered appropriate options to stabilize the enzyme on the surface of electrochemical sensors due to their chemical reactivity, high stability, and appropriate mechanical resistance. Physical adsorption and covalent bond with carbon nanotubes are among the most common methods to stabilize enzymes on the surface of these nanomaterials. The designed biosensor has low NADH oxidation potential, high sensitivity, high stability, and appropriate linear range. The simplicity in the design of the biosensor makes it an ideal example in the design of other biosensors based on dehydrogenase. By creating some changes in these tests, they can be used in laboratories, clinics, and houses. Results of the research have been published in March 2013 in IET Nanobiotechnology, vol. 7, issue 1. For more information about the details of the research, study the full article on pages 1-6 on the same journal.