title: Laser chemosensor with rapid responsivity and inherent memory based on a polymer of intrinsic microporosity.
abstract: This work explores the use of a polymer of intrinsic microporosity (PIM-1) as the active layer within a laser sensor to detect nitroaromatic-based explosive vapors. We show successful detection of dinitrobenzene (DNB) by monitoring the real-time photoluminescence. We also show that PIM-1 has an inherent memory, so that it accumulates the analyte during exposure. In addition, the optical gain and refractive index of the polymer were studied by amplified spontaneous emission and variable-angle ellipsometry, respectively. A second-order distributed feedback PIM-1 laser sensor was fabricated and found to show an increase in laser threshold of 2.5 times and a reduction of the laser slope efficiency by 4.4 times after a 5-min exposure to the DNB vapor. For pumping at 2 times threshold, the lasing action was stopped within 30 s indicating that PIM-1 has a very fast responsivity and as such has a potential sensing ability for ultra-low-concentration explosives.
authors.affiliation: Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews, Fife KY16 9SS, UK. yw244@st-and.ac.uk
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.forename: Neil B
authors.initials: NB
authors.lastname: McKeown
authors.forename: Kadhum J
authors.initials: KJ
authors.lastname: Msayib
authors.forename: Graham A
authors.initials: GA
authors.lastname: Turnbull
authors.forename: Ifor D W
authors.initials: ID
authors.lastname: Samuel
mesh_terms: D000042:Absorption; D004136:Dinitrobenzenes / Q000737:chemistry; D007834:Lasers; D008163:Luminescent Measurements; D055095:Optics and Photonics / Q000295:instrumentation*; D011108:Polymers / Q000737:chemistry*; D016062:Porosity
chemical_list: D004136:Dinitrobenzenes; D011108:Polymers