A New Radio Frequency Plasma Oxygen Primary Ion Source on Nano Secondary Ion Mass Spectrometry for Improved Lateral Resolution and Detection of Electropositive Elements at Single Cell Level.
An important application field of secondary ion mass spectrometry at the nanometer scale (NanoSIMS) is the detection of chemical elements and, in particular, metals at the subcellular level in biological samples. The detection of many trace metals requires an oxygen primary ion source to allow the generation of positive secondary ions with high yield in the NanoSIMS. The duoplasmatron oxygen source is commonly used in this ion microprobe but cannot achieve the same quality of images as the cesium primary ion source used to produce negative secondary ions (C(-), CN(-), S(-), P(-)) due to a larger primary ion beam size. In this paper, a new type of an oxygen ion source using a rf plasma is fitted and characterized on a NanoSIMS50L. The performances of this primary ion source in terms of current density and achievable lateral resolution have been characterized and compared to the conventional duoplasmatron and cesium sources. The new rf plasma oxygen source offered a net improvement in terms of primary beam current density compared to the commonly used duoplasmatron source, which resulted in higher ultimate lateral resolutions down to 37 nm and which provided a 5-45 times higher apparent sensitivity for electropositive elements. Other advantages include a better long-term stability and reduced maintenance. This new rf plasma oxygen primary ion source has been applied to the localization of essential macroelements and trace metals at basal levels in two biological models, cells of Chlamydomonas reinhardtii and Arabidopsis thaliana.
Université de Pau et des Pays de l'Adour , CNRS, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), UMR 5254, 64000 Pau, France.
Julien
J
Malherbe
Université de Pau et des Pays de l'Adour , CNRS, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), UMR 5254, 64000 Pau, France.
Florent
F
Penen
Université de Pau et des Pays de l'Adour , CNRS, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), UMR 5254, 64000 Pau, France.
Marie-Pierre
MP
Isaure
Martin-Luther Universität Halle-Wittenberg , Institute for Biochemistry and Biotechnology, Plant Biochemistry, Weinbergweg 22, 06120 Halle (Saale), Germany.
Julia
J
Frank
Martin-Luther-Universität Halle-Wittenberg , Biozentrum, Weinbergweg 22, 06120 Halle (Saale), Germany.
Gerd
G
Hause
Martin-Luther Universität Halle-Wittenberg , Institute for Biochemistry and Biotechnology, Plant Biochemistry, Weinbergweg 22, 06120 Halle (Saale), Germany.
Dirk
D
Dobritzsch
Université de Bordeaux , Bordeaux Imaging Center UMS 3420 CNRS - US4 INSERM, Pôle d'Imagerie Électronique, 146 Rue Léo Saignat, 33076 Bordeaux, France.
Etienne
E
Gontier
CAMECA , 29 Quai des Grésillons, 92622 Gennevilliers, France.
François
F
Horréard
CAMECA , 29 Quai des Grésillons, 92622 Gennevilliers, France.
François
F
Hillion
Université de Pau et des Pays de l'Adour , CNRS, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), UMR 5254, 64000 Pau, France.
Dirk
D
Schaumlöffel
D017360:Arabidopsis / Q000737:chemistry; D016825:Chlamydomonas reinhardtii / Q000737:chemistry; D019216:Metals, Heavy / Q000032:analysis; D010100:Oxygen / Q000737:chemistry*; D058626:Plasma Gases / Q000737:chemistry*; D011846:Radio Waves; D059010:Single-Cell Analysis; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods*; D014131:Trace Elements / Q000032:analysis*
D019216:Metals, Heavy; D058626:Plasma Gases; D014131:Trace Elements; D010100:Oxygen