Jean-Luc Vorng oral presentation (FN3-Fri1-2-1)
Development and characterization of a test device for measurement of molecular lateral resolution for SIMS
National Physical Laboratory, Hampton Road, TW11 0LW Teddington, United Kingdom
SIMS is becoming an important technique for the identification and localization of pharmaceuticals and biomolecules in tissue and cells. The quality of the image is affected by both the lateral resolution and the sensitivity of the instrument. Here, we have developed a well characterized test device to measure the SIMS lateral resolution for organic molecules. The device consists of a logarithmically spaced periodic grating of stripes of PEG/Biotin/streptavidin on gold and silicon. The test device was fabricated with UV lithography. The features spacing range from 1 mm to 2 m. The strong non-specific binding between streptavidin and biotin allows us to easily wash away the protein from the silicon regions of the test device. [1-2].
Each step of the functionalization process was characterized with ToF-SIMS. We show specific binding of the biotin-PEG-SH on the gold surface (Figure 1), as well as, the specific binding of streptavidin to the biotin-PEG-SH by the follow up of the small fragment of biotin . We demonstrate the utility of the device to measure the ToF-SIMS and 3D OrbiSIMS lateral resolution for different primary ion beams using the spread edge function (ESF) and the image quality via the measurement of the modulation transfer function (MTF) as described in a previous work . Progress towards an interlaboratory study will be discussed.