Sensor100 June 2014
6
“Graphene Bio-Field-EffectTransistor Myth”
The following email correspondence was contributed by Prof. Jiri Janata, Geor-
gia Tech. It is reproduced here verbatim, but the student’s name has been
deleted.
On Jun 19, 2014, at 8:24 xxxx wrote:
Dear prof.
I read your paper and it made me to think if what i am doing is right or not in
my research.
i work on bio sensors based on CNT films and we record some gate leakage
in order of nano amps.
my test volume is around 50 micro ltr and salt concentration KCl of 1 nano
molar.
in this case the gate leakage does not goes down even after 2 hours and keeps
on flowing does it means that we have changed the concentration something
in the volume.
If so what could it be that makes the current flow for so long and not de-
creasing with time.
I found your paper quite true and fact that no one reports the gate leakage
current is also very much true. It would be a great help if you could say if i
am doing a mistake in interpreting the result.
sincere regards, xxxx
OnThu, Jun 19, 2014 at 3:27 PM, Jiri Janata wrote:
Dear xxxx:
The leakage current is serious issue and it is always indication that electri-
cal integrity is failing.This is a major problem particularly in potentiometric
devices. However, the even more serious issue is the non-polarizability of all
interfaces that contain an electrolyte.That is the main point of my paper and
is is also the main reason why potentiometric biosensors cannot work.You
would find a more detail discussion of this problem in my book “Principles of
Chemical Sensors”, Springer 2009. Good luck and best regards,
Jiri Janata
