New technique to detect fingerprints on wet paper

Researchers at the Hebrew University (HU) in Jerusalem, Israel, have found a new way to detect fingerprints on wet paper, a task that earlier technology was difficult to implement.

Typically, when investigators want to find fingerprints on paper, they often use the technique of sprinkling gold nanoparticles onto the surface of the paper, the gold particles sticking to the amino acids in the remnants of the left hand to show the fingerprints. They then proceeded to use silver nanoparticles to enhance their fingerprints.

By using fat and black-and-white contrast techniques, new methods
Clear fingerprints even in wet paper environments. (Photo: Gizmag)

However, the image obtained with very low contrast. To overcome these drawbacks, the team at the HU Institute of Chemistry replaced the new method that caused the paper to be sprinkled with gold turning black, highlighting the fingerprints in white. Thanks to the contrast of white and black, the fingerprints appear more clearly.

Because the method uses only sebum (a substance secreted by the sebaceous glands to prevent hair and skin from drying out) from fingerprints rather than relying on amino acids in sweat-the substance is easily lost. When the paper is wet, new technology can help the police track fingerprints even when the papers are wet. As fat is not washed away.

The new fingerprinting method was presented in English in the German Chemistry Association's Angewandte Chemie.