PMID- 19367840
OWN - NLM
STAT- MEDLINE
DCOM- 20090427
LR  - 20240418
IS  - 1530-6984 (Print)
IS  - 1530-6992 (Electronic)
IS  - 1530-6984 (Linking)
VI  - 8
IP  - 12
DP  - 2008 Dec
TI  - Mechanism and optimization of pH sensing using SnO2 nanobelt field effect 
      transistors.
PG  - 4179-84
AB  - We report a systematic investigation about the mechanism of pH sensing using SnO2 
      nanobelt field effect transistors (FETs). The FETs, based on single SnO2 
      nanobelts, are channel-limited and with proper contact passivation; the pH 
      sensing was conducted with sodium phosphate solutions through integrated 
      microfluidics. The responses of the FET channel conductance to pH were measured 
      at different gate voltages: a linear pH dependence was observed in the linear 
      transport "on" state, while an exponential dependence was observed in the 
      subthreshold regime. Measurements at the same pH but different ion concentrations 
      demonstrated that the FET's pH sensitivity decreases logarithmically with the ion 
      concentration. The effect of APTES-functionalization was evaluated by comparing 
      the pH responses of the same device with and without the surface modification. 
      The APTES functionalization results in a slight enhancement of the pH sensitivity 
      and a large suppression of the noise level, leading to marked improvement in the 
      signal-to-noise ratio. The results indicate that the pH sensing is based on a 
      screened field-effect response of the FETs to the surface 
      protonation/deprotonation on the nanobelt. This study provides several useful 
      guidelines for optimizing the sensor performance for chemical and biomolecular 
      detection.
FAU - Cheng, Yi
AU  - Cheng Y
AD  - Department of Physics and Center for Materials Research and Technology, Florida 
      State University, Tallahassee, Florida 32306, USA.
FAU - Xiong, P
AU  - Xiong P
FAU - Yun, C Steven
AU  - Yun CS
FAU - Strouse, G F
AU  - Strouse GF
FAU - Zheng, J P
AU  - Zheng JP
FAU - Yang, R S
AU  - Yang RS
FAU - Wang, Z L
AU  - Wang ZL
LA  - eng
GR  - R21 GM079592/GM/NIGMS NIH HHS/United States
GR  - R21 GM079592-02/GM/NIGMS NIH HHS/United States
GR  - GM079592/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - Nano Lett
JT  - Nano letters
JID - 101088070
RN  - 0 (Tin Compounds)
RN  - KM7N50LOS6 (stannic oxide)
SB  - IM
MH  - *Hydrogen-Ion Concentration
MH  - Microfluidics
MH  - *Nanotechnology
MH  - Tin Compounds/*chemistry
PMC - PMC2771949
MID - NIHMS88255
EDAT- 2009/04/16 09:00
MHDA- 2009/04/28 09:00
PMCR- 2009/12/01
CRDT- 2009/04/16 09:00
PHST- 2009/04/16 09:00 [entrez]
PHST- 2009/04/16 09:00 [pubmed]
PHST- 2009/04/28 09:00 [medline]
PHST- 2009/12/01 00:00 [pmc-release]
AID - 10.1021/nl801696b [doi]
PST - ppublish
SO  - Nano Lett. 2008 Dec;8(12):4179-84. doi: 10.1021/nl801696b.