ZnO nanowires as effective luminescent sensing materials for nitroaromatic derivatives

Roy Aad (1) , Vesna Simic (2) , Loïc Le Cunff (3, 1) , Licinio Rocha (2) , Vincent Sallet (4) , Corinne Sartel (4) , Alain Lusson (4) , Christophe Couteau (1) , Gilles Lerondel (1)

1 LNIO - Laboratoire de Nanotechnologie et d'Instrumentation Optique
2 LCAE - Laboratoire Capteurs et Architectures Electroniques
3 UMT Géno-vigne® - Géno-vigne®
4 GEMAC - Groupe d'Etude de la Matière Condensée

We report on the efficient room-temperature photoluminescence (PL) quenching of ZnO in the presence of 2,4-dinitrotoluene (DNT) vapor and for concentration as low as 180 ppb. Compared to ZnO thin films, ZnO nanowires exhibit a strong (95%) and fast (41 s) quenching of the PL intensity in the presence of DNT vapor. Assuming that the PL quenching is due to a trapping of the ZnO excitons by adsorbed DNT molecules, Monte-Carlo calculations show that the nanometric dimensions as well as the better crystallographic quality (longer mean free path) of the ZnO nanowires result in an enhanced trapping process at the origin of the improved sensing properties of the nanowires. The results demonstrate the importance of nanostructures in improving the sensitivity of ZnO. The study also reveals the sensing capability of ZnO nanowires and paves the path towards the potential realization of low-cost sub-ppb nitroaromatic derivative sensors.

Keywords: sub-ppb nitroaromatic derivative sensors; nanostructure; crystallographic quality; nanometric dimension; Monte-Carlo calculations; 4-dinitrotoluene (DNT); ZnO excitons; nanowire; 2; photoluminescence; quenching; ZnO

Domains: Physics [physics]; Physics [physics]; Instrumentation and Detectors [physics.ins-det]; Engineering Sciences [physics]; Optics / Photonic

Roy Aad, Vesna Simic, Loïc Le Cunff, Licinio Rocha, Vincent Sallet, et al.. ZnO nanowires as effective luminescent sensing materials for nitroaromatic derivatives. Nanoscale, 2013, 5, pp.9176. ⟨10.1039/C3NR02416D⟩. ⟨cea-01791239⟩