Elevating Latent Fingerprint Visualization: Sebaceous Fingerprint Residues-Responsive Fluorescent Powders for Colour-Changing Visual Enhancement

A new fluorescent fingerprint powder (DFF-MMT) was formulated by blending cyclic chalcone dye DFF with montmorillonite (MMT), which can develop latent fingerprints (LFPs) with exceptional resolution and contrast on various surfaces, including ordinary glass, tin foil, marble, LED screens, and materials with distinct colors and fluorescent backgrounds. The fluorescence of DFF-MMT transforms from orange to bright yellow with LFPs, allowing for a flawless visualization of fingerprints on uneven surfaces or materials with static electricity. Impressively, fingerprints developed by DFF-MMT can be stored for over 21 months and conveniently duplicated. The developed LFPs by DFF-MMT still keep high quality under the influence of aquatic condition, illumination and thermal effects. DFF-MMT also exhibits benefits, such as affordability, real-time, high-resolution, high-contrast development and no damage to DNA, making it an ideal choice for sophisticated criminal investigations.