Open AccessCalcium Ion Detection Using Miniaturized InN-based Ion Sensitive Field Effect Transistors
Author(s) -
Kun-Wei Kao,
Yun-Wen Su,
Yi Lu,
Shangjr Gwo,
J. Andrew Yeh
Publication year - 2012
Publication title -
international journal of automation and smart technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.148
H-Index - 10
ISSN - 2223-9766
DOI - 10.5875/ausmt.v2i1.117
Subject(s) - isfet , detection limit , materials science , transistor , field effect transistor , ion , optoelectronics , calcium , analytical chemistry (journal) , aqueous solution , nanotechnology , chemistry , electrical engineering , chromatography , engineering , organic chemistry , voltage , metallurgy
An Ultrathin (~10 nm) InN ion sensitive field effect transistor (ISFET) with gate regions functionalized with phosphotyrosine (p-Tyr) is proposed to detect calcium ions (Ca2+) in aqueous solution. The ISFET was miniaturized to a chip size of 1.1 mm by 1.5 mm and integrated at the tip of a hypodermic injection needle (18 G) for real-time and continuous monitoring. The sensor shows a current variation ratio of 1.11% with per decade change of Ca2+ and a detection limit of 10-6 M. The response time of 5 sec. reveals its great potential for accomplishing fast detection in chemical and physiological sensing applications. The sensor would be applied in medical diagnosis and used to monitor continuous and real-time variations of Ca2+ levels in human blood in the near future