[10p-Z12-1~21] 12.6 Nanobiotechnology

▼ [10p-Z12-11] The effect of elevated temperature on fluorocarbon thin film for pH sensing using boron-doped diamond solution-gate field-effect transistors

〇YuHao Chang¹, Yutaro Iyama¹, Kaito Tadenuma¹, Syuto Kawaguchi¹, Teruaki Takarada¹, Hiroshi Kawarada^1,2 (1.Waseda Univ., 2.Kagami Memorial Research Inst. for Material Science and Tech.)

Keywords:polycrystalline diamond, fluorine termination, pH sensor

Diamond has many appealing properties including chemical inertness, biocompatibility, and simple chemical modification on the surface. These properties are favorable for biosensing applications, especially pH sensing. In addition, the lack of passivation layer as opposed to ISFETs has enabled direct sensing on the device’s channel. Since 2001, we have reported diamond SGFETs where the semiconductor surface was directly immersed in electrolyte solution and the drain current was controlled by an electric double layer at the diamond surface¹. Several studies utilizing different functional groups including hydrogen, oxygen nitrogen, and fluorine have been report^2,3,4. We have also reported pH insensitive results by using fluorine-terminated diamond SGFETs where the diamond surface is dominated by C-F bonding⁵. Comparing with this C-F bonding, fluorocarbon thin film is composed of layers of C-CF, C-F, C-F₂, and C-F₃. In this work, we investigate the use of fluorocarbon thin film with boron-doped diamond (BDD) SGFETs for pH sensing for the first time.