Volatile organic compound detection using nanostructured copolymers.
Regioregular polythiophene-based conductive copolymers with highly crystalline nanostructures are shown to hold considerable promise as the active layer in volatile organic compound (VOC) chemresistor sensors. While the regioregular polythiophene polymer chain provides a charge conduction path, its chemical sensing selectivity and sensitivity can be altered either by incorporating a second polymer to form a block copolymer or by making a random copolymer of polythiophene with different alkyl side chains. The copolymers were exposed to a variety of VOC vapors, and the electrical conductivity of these copolymers increased or decreased depending upon the polymer composition and the specific analytes. Measurements were made at room temperature, and the responses were found to be fast and appeared to be completely reversible. Using various copolymers of polythiophene in a sensor array can provide much better discrimination to various analytes than existing solid state sensors. Our data strongly indicate that several sensing mechanisms are at play simultaneously, and we briefly discuss some of them.
Li
Bo
B
Electrical and Computer Engineering Department, Chemistry Department, Robotics Institute, and Chemical Engineering Department, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
Sauvé
Genevieve
G
Iovu
Mihaela C
MC
Jeffries-El
Malika
M
Zhang
Rui
R
Cooper
Jessica
J
Santhanam
Suresh
S
Schultz
Lawrence
L
Revelli
Joseph C
JC
Kusne
Aaron G
AG
Kowalewski
Tomasz
T
Snyder
Jay L
JL
Weiss
Lee E
LE
Fedder
Gary K
GK
McCullough
Richard D
RD
Lambeth
David N
DN
D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005740:Gases / Q000032:analysis*; D008839:Microelectrodes; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D009930:Organic Chemicals / Q000032:analysis*; D011108:Polymers / Q000032:analysis / Q000737:chemistry*; D013876:Thiophenes / Q000032:analysis / Q000737:chemistry*; D014159:Transducers; D014835:Volatilization
D005740:Gases; D009930:Organic Chemicals; D011108:Polymers; D013876:Thiophenes; C066730:polythiophene