[25a-P04-1~14] 12.7 Biomedical Engineering and Biochips

[25a-P04-9] Biosensor for ketone body detection

Kazushi Suzuki¹, 〇Hitoshi Muguruma^1,2, Hisanori Iwasa³, Takeshi Tanaka², Tetsuo Shimizu², Atsunori Hiratsuka², Yoko Hoshino², Katsumi Tsuji³, Takahide Kishimoto³ (1.Shibaura Inst., 2.AIST, 3.Toyobo)

Keywords:3-hydroxybutyrate dehydrogenase, carbon nanotube

We report an amperometric biosensor strip for the detection of ketone 3-hydroxybutyrate (3HB) in blood. The biosensor strip has small volume (ca. 2 microL) capillary chamber. Working electrode is consisted with carbon nanotube (CNT) and enzyme 3HB dehydrogenase (HBDH). The CNT is dispersed in aqueous media with surfactant sodium cholate and it is mixed with HBDH solution. UV-vis, electrochemical impedance spectroscopy, and atomic force microscopy show that the CNT well-dispersed in aqueous solution. Any kinds of CNTs enhance the current due to enzymatic reaction without electron transfer mediator. The small amount (ca. 0.5 microL) of HBDH/CNT solution is dipped into the small area of (1.5 mm²) electrode and is sealed with coversheet to make the reaction chamber. The sensor can detect 3-hydroxybutyrate in human serum at the range of 0.05-4.4 mM, which can cover the physiological use. The response time was 15 s.