Micro-x-ray fluorescence(MXRF) is among the newest technology used to detect fingerprints. It is a new visualization technique which rapidly reveals the elemental composition of a sample by irradiating it with a thin beam of X-rays without disturbing the sample. It was discovered recently by scientists at the Los Alamos National Laboratory. The newly discovered technique was then first revealed at the 229th national meeting of the American Chemical Society, the world’s largest scientific society. This new discovery could prove to be very beneficial to the law enforcement world, because it is expected that MXRF will be able to detect the most complex molecules in fingerprints.
Michael Bernstein of the American Chemical Society describes how the process works "Salts such as sodium chloride and potassium chloride excreted in sweat are sometimes present in detectable quantities in fingerprints. Using MXRF, the researchers showed that they could detect the sodium, potassium and chlorine from such salts. And since these salts are deposited along the patterns present in a fingerprint, an image of the fingerprint can be visualized producing an elemental image for analysis." This basically means that we can “see” a fingerprint because the salts are deposited mainly along the patterns present in a fingerprint.
Since MXRF technology uses X-ray technology to detect fingerprints, instead of traditional techniques, the image comes out much clearer. Traditional fingerprints are performed by using a technique called Contrast Enhancement which involves using powders, liquids, or vapors to add color to the fingerprint so it can be easily distinguished. But sometimes this process may alter the fingerprint or may not be able to detect some of the more complex molecules.