Detection of Molecular-Surface Adsorbates at the 10(-6)-Monolayer Level and Below
Voumard, P., Zhan, Q., & Zenobi, R. (1995). Detection of Molecular-Surface Adsorbates at the 10(-6)-Monolayer Level and Below. Chemical Physics Letters, 239(1-3), 89-94. DOI: 10.1016/0009-2614(95)00436-8
Ultrathin molecular surface overlayers were deposited in an UHV chamber and were detected using pulsed infrared laser desorption followed by resonant laser post-ionization. A single-shot detection limit in the 10?6 monolayer range was found for aniline adsorbed on silica, a system whose adsorption, laser desorption and ionization properties have been well studied. An excellent signal-to-noise ratio, as well as some simple modifications that will improve the detection efficiency suggest ultimate detection limits in the 10?9 to 10?10 ML range with this scheme.