Research Projects
To image antibody antigen interaction through the use of Atomic Force Microscopy.
The DEPSCoR project has been looking different paint samples to find correlations between AFM image and composition of the paint. Below are some of our elemental maps showing rich locations of various chemicals in a paint surface.
To utilize Atomic Force Microscopy to image effects of marine organisms on different surfaces and the organisms themselves.
Red areas are titanium rich, green areas are iron rich, and blue are silicon rich.
Project in conjunction with the Idaho National Environmental Engineering Laboratory.
Currently the focus of this project is the characterization of known clay samples using ToF SIMS. The characterization is of the adsorption and desorption of cations as a function of laser ablation. Through the use of ToF SIMS and Origin a series of data graphs are being produced for later use.
Why LASIMS?
The LASIMS is being developed to meet a need of the Idaho National Engineering and Environmental Laboratory (INEEL). Cold War era nuclear waste store at INEEL’s facility has caused groundwater contamination.In order to analyze the contamination and characterize the contaminants interaction with soil a new analytical technique was necessary. It was necessary for this technique to meet two requirements: 1) Iit must generate large fragment molecules and image their distribution on the subsurface soil contaminated with organic and inorganic toxic materials and 2) It must increase the detection sensitivity of the radionuclide trace elements absorbed in the subsurface soil.
Most current surface analysis techniques do not meet the objectives stated above. Mass spectroscopy techniques offered the most promise in that not only can one have high detection sensitivities of molecular fragments but also molecular imaging is possible. Unfortunately the focused ion beams used for mass spec have limited probability of desorbing large molecular fragment ions, which are very important to determine the interaction mechanism of the toxic compounds and ions with the underlying subsurface soil. Lasers have been used to generate large molecular fragment ions under special sample preparation techniques such as the one used in matrix assisted laser desorption mass spectrometry (MALDI). LASIMS takes advantage of both mass spectroscopy and laser desorption by combining the capabilities of ToFSIMS (time of flight secondary ion mass spectroscopy) and ToFLDMS (time of flight laser desorption mass spectroscopy).
What is LASIMS?
LASIMS proposes that SIMS and LDS can be combined to analyze a mineral surface. This technique will utilize a short laser pulse to bring the surface of the sample to just under laser desorption threshold by means of heating. A highly concentrated Ga+ beam that is well synchronized to the laser pulse will then be used to further energize the sample surface to yield molecular desorption from that surface.
One problem with SIMS alone technique is the fact that information is gathered from a close proximity of the point of impact of the primary ion beam, but the laser used with the LASIMS bethod will bring to desorption threshold a large area. The result is that molecular information can now be gathered from an undamaged area in the vicinity of the point of impact of the Ga+ beam. This method has the advantage over unassisted SIMS in that the yield of chemical information from a minimal microscopic area is greatly increased.
How it works?
LASIMS proposes that SIMS and LDS can be combined to analyze a mineral surface. This technique will utilize a short laser pulse to bring the surface of the sample to just under laser desorption threshold by means of heating. A highly concentrated Ga+ beam that is well synchronized to the laser pulse will then be used to further energize the sample surface to yield molecular desorption from that surface.
One problem with SIMS alone technique is the fact that information is gathered from a close proximity of the point of impact of the primary ion beam, but the laser used with the LASIMS bethod will bring to desorption threshold a large area. The result is that molecular information can now be gathered from an undamaged area in the vicinity of the point of impact of the Ga+ beam. This method has the advantage over unassisted SIMS in that the yield of chemical information from a minimal microscopic area is greatly increased.
Figure 1: Schematic representation of the LASIMS method. The primary ion beam (Ga+) is preceded by a short laser pulse.
Figure 2: Schematic representation of the LASIMS method. The primary ion beam (Ga+) is preceded by a short laser pulse.
MAP student program to use Atomic Force Microscopy and Scanning Electron Microscopy to measure the accuracy of an Anatech Hummer VII sputter coater and to measure the roughness of three different coatings: gold, gold/palladium, and platinum. Clik for results.