Visualization of latent fingerprints based on composites of dye-doped cellulose with red emissive fluorescence

Novel cellulose-based composites were developed by integrating the rhodamine B (RhB) with cellulose microparticles and used to detect latent fingerprints (LFPs). The cellulose-based composites containing the various contents of RhB (5.4, 9.7, and 19.6 mg g) with good luminescence were obtained by simple adsorption method. Under 365 nm light irradiation, cellulose-based composite can produce the bright red fluorescence in solid-state. The images of the LFPs on the surface of the substrates with variable textures and colors can be detected with integral ridge patterns and finely clear detail characteristics in level 2 (such as scar, core, island, bifurcation and termination) and level 3 (such as sweat holes and line shape). The fresh and aging LFPs can be finely detected by the cellulose-based composite with the little interference of background because the red-emissive can efficiently avoid the interference from self-fluorescence of the substrates. These results suggested that the cellulose-based composite with favorable applicability and dependability could be a promising candidate for the visualization of the LFPs.