Open AccessTowards in vivo biosensors for low‐cost protein sensing
Author(s) -
Ramesh A.,
Ren F.,
Berger P.R.,
Casal P.,
Theiss A.,
Gupta S.,
Lee S.C.
Publication year - 2013
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2012.4283
Subject(s) - capacitor , alkali metal , materials science , silicon dioxide , biosensor , semiconductor , ion , transistor , optoelectronics , silicon , dielectric , oxide , nanotechnology , voltage , chemistry , electrical engineering , composite material , engineering , organic chemistry , metallurgy
In vivo biosensing requires stable transistor operation in high‐salt concentration bodily fluids while exhibiting impermeability to mobile alkali ions that would otherwise render the metal‐oxide‐semiconductor (MOS) threshold voltage to drift. Metal oxide semiconductor capacitor structures using Al 2 O 3 as the gate dielectric were soaked in a sterile physiological buffer solution (PBS) up to 24 hours and for thicknesses from 100 to 10 nm. The triangular voltage sweep technique characterised alkali ion penetration, and measured no detectable alkali ions for the Al 2 O 3 capacitors. By contrast, the dose of alkali ions in silicon dioxide MOS capacitors steadily increased with increasing soak times in the PBS solution.