Heme-enabled electrical detection of carbon monoxide at room temperature using networked carbon nanotube field-effect transistors

Thiolated heme molecules-enabled electric detection of carbon monoxide at room temperature using single-walled carbon nanotubes (SWNT) network field-effect transistors (SNFET) was used to detect the change of drain current upon exposure to 4.9 ppm of CO. SNFET were fabricated in a top contact device geometry, where a highly p-doped silicon wafer with an 100-nm-thick SiO 2 layer was used as a back gate. No significant drain current response is observed for the Au-SNFET after the gas flow is switched from N 2 to CO. The thiolated heme-modified Cr-SNFET could be reused for up to 40 cycles of N2-CO testing without any deterioration in the sensing response. The results show that for he-Cr-SNFET, the drain current is decreased and there is a small negative shift in threshold voltage while switching from N2 to 4.9 ppm of CO.