Facile and scalable fabrication of chemiresistive sensor array for hydrogen detection based on gold-nanoparticle decorated SWCNT network

We report a facile and scalable process to fabricate chemiresistive hydrogen sensors based on the singlewalled carbon nanotube (SWCNT) network decorated with metal nanoparticles (NPs). In order to obtain the statistical and reliable results in the detection, 100 unitary sensing array are fabricated on a single chip at one go. Two device structures were studied; one coated on top of the SWCNT network (SWCNN) and the other sandwiched by Au-NPs (the Au/SWCNT/Au structure). The sensor response of the AuNP decorated SWCNN was found to be similar to 3.6 and 18.5 times superior to that of the Cu- and Sn-NP coated SWCNN, respectively, at room temperature. Sensing response of the sensor was further improved 3 times from 16.1 to 50% by using the sandwiched structure of Au/SWCNN/Au. Based on reproducible electrical responses and statistical understanding, we also found that the enhancement of sensing response is proportional to the increase of the change in resistance by the Au-NP decoration. (C) 2014 Elsevier B.V. All rights reserved.