Sensitive development of latent fingerprints using Rhodamine B-diatomaceous earth composites and principle of efficient image enhancement behind their fluorescence characteristics

Abstract

Latent fingerprints, by definition, are not directly visible traces that usually found at crime scenes and need physical or chemical treatment before image capture and fingerprint identification. Research of novel powders for latent fingerprint development and establishment of efficient methods for fingerprint image enhancement have always been key focuses in forensic science and related fields involving chemistry, materials science and biology. Relying on physical adsorption between cationic fluorophores and porous silica, Rhodamine B-diatomaceous earth composites have been prepared as novel fluorescent fingerprint powders. A luminescence mode for latent fingerprint development and image enhancement that matches the fluorescence characteristics of these composites has been theoretically explained and a fingerprint image capture and processing system designed based on it has been successfully constructed. In the luminescence mode, the first and second level information of a latent fingerprint on the surface of an object showing either background interference or not can be precisely visualized and captured. This entire approach is demonstrated to be promising for scenarios of practical application.