Fluorescent Conjugated Polymers for Latent Blood Fingermark Visualization with Enhanced Ridge Details

ABSTRACT While fluorescent polymers have demonstrated remarkable effectiveness in the visualization of latent sweat fingermarks, research and application in the crucial area of blood fingermark visualization remain relatively scarce. To bridge this gap, this paper delves into and reports the synthesis and characterization of a series of PF‐SO10 (blue), PF‐SO10‐BT1(green), and PF‐SO10‐DTBT1 (red) fluorescent polymers. These multicolored polymers are characterized to contain excellent ultraviolet‐exciting fluorescence properties, which lays a foundation for their forensic application in bloodstain visualization. Experimental results indicate that our multicolor fluorescent polymer solution can be precisely applied to enhance blood fingermarks on various complex substrate surfaces, including glass, metal, plastic, and ceramic materials, achieving effective coverage and enhancement. Notably, this method is verified to possess significant characteristics of high contrast and low background interference through semiquantitative grayscale analysis, enabling the enhanced ridge details of blood fingermark in complex surfaces with a wide range of applicability. This study thereby establishes a robust and versatile platform for high‐contrast blood fingermark detection, offering promising implications for future forensic investigations and practical crime scene analysis.