Papers Abstract

Room temperature monitoring of hydrogen peroxide vapor using platinum nanoparticles-decorated single-walled carbon nanotube networks
Sensitive and selective vapor detection of hydrogen peroxide have been especially demanded in the fields of both the detection of peroxide-based explosives and the analysis of exhaled breath for clinical diagnosis. In this paper, we report hydrogen peroxide vapor sensor transducers operated at room temperature using platinum (Pt) nanoparticles-decorated single-walled carbon nanotube (SWCNT) network films. The SWCNT films are coated on a SiO2/Si substrate using a low-cost, effective, and scalable spray printing process. Then, the Pt nanoparticles are decorated on SWCNT surfaces by an effective photo-reduction process, which is performed by immersing the SWCNT films into the H2PtCl6 solution mixed with methanol and deionized water under UV irradiation with a wavelength of 254 nm. The active organic radicals produced from methanol under UV irradiation rapidly reduce PtCl62− ions to Pt0 on SWCNT surfaces within 5 min. The nanoparticle size is modulated from 2 to 10 nm by controlling the molar concentrations of the H2PtCl6 solutions in a range from 2 to 50 mM. By forming interdigitated electrodes on the Pt nanoparticles-decorated SWCNT films, sensor transducers are fabricated for detection of hydrogen peroxide (H2O2) vapor. The sensors show a linear response to H2O2 vapor in a range from ca. 2 to 60 ppm and weak responses to NH3 and SO2 gases and negligible responses to NO2, CO, and C6H6 gases, which are representative biomarkers of exhaled breath. We expect that in the future, our sensing films will be able to be utilized in highly sensitive, real-time hydrogen peroxide vapor sensors.