Metal nanoparticles and DNA co-functionalized single-walled carbon nanotube gas sensors

Metal/DNA/SWNT hybrid nanostructure-based gas sensor arrays were fabricated by means of ink jet printing of metal ion chelated DNA/SWNTs on microfabricated electrodes, followed by electroless deposition to reduce metal ions to metal. DNA served as a dispersing agent to effectively solubilize pristine SWNTs in water and as metal ion chelating centers for the formation of nanoparticles. Noble metals including palladium, platinum, and gold were used because the high binding affinity toward specific analytes enhances the selectivity and sensitivity. The sensitivity and selectivity of the gas sensors toward various gases such as H 2 , H 2 S, NH 3 , and NO 2 were determined at room temperature. Sensing results indicated the enhancement of the sensitivity and selectivity toward certain analytes by functionalizing with different metal nanoparticles (e.g., Pd/DNA/SWNTs for H 2 and H 2 S). The combined responses give a unique pattern ...

Heng C Su, Miluo Zhang, Wayne Bosze, Jae-Hong Lim and Nosang V Myung

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