Theoretical optimization method of buffer ionic concentration for protein detection using field effect transistors

Sho Hideshima*, Hila Einati, Takahiro Nakamura, Shigeki Kuroiwa, Yosi Shacham-Diamand, Tetsuya Osaka


研究成果: Article査読

22 被引用数 (Scopus)


Field effect transistors (FETs) may respond to charge variations occurring when proteins are adsorbed to the gate surface. The electrolyte electrostatic screening allows a practical detection of charges that are only within a distance of approximately the double layer thickness, which is related to the Debye length in the electrolyte. Hence, operating the FET biomolecular sensors at the highest possible ionic concentration improves reproducibility; however, it may reduce the signal if the concentration is too high. Here, we propose an optimization method of the buffer ionic concentration using a figure of merit "charge number," Zd, which is defined as the ratio between the effective number of the surface charges and the number of immobilized molecules. The theoretical Zd was calculated using a three-dimensional conformation data taken from the Protein Data Bank. The Z d was obtained from the total number of four charged amino acids of avidin, arginine (positive), lysine (positive), aspartic acid (negative), and glutamic acid (negative), which are within the double layer length from the surface. To verify this model, we chose avidin-biotin interaction. The experimental Zd, which was obtained for three buffer concentrations, matched the theoretical Zd. This method shortens the solution calibration time and reduces the analyte amount.

ジャーナルJournal of the Electrochemical Society
出版ステータスPublished - 2010 11月 24

ASJC Scopus subject areas

  • 電子材料、光学材料、および磁性材料
  • 再生可能エネルギー、持続可能性、環境
  • 表面、皮膜および薄膜
  • 電気化学
  • 材料化学


「Theoretical optimization method of buffer ionic concentration for protein detection using field effect transistors」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。