From invisible to visible: a concise review on conjugated polymer materials in latent fingerprint analysis

AbstractOver the past decades, significant scientific and technological advancements have been made in the field of forensic science, particularly in the advancement of fingerprint technology. Latent fingerprints (LFPs) are considered to be the most crucial evidence found at crime scenes, necessitating extensive research efforts for their advancement. Conversely, conjugated polymers are extremely adaptable substances that are utilized in many domains like photonics, bio-imaging, optoelectronics, nanomedicine, and more. Conjugated polymers, especially conjugated polymer nanoparticles and polymer dots, exhibit remarkable photophysical and chemical features that contribute to their high resolution, enhanced selectivity, and heightened sensitivity in the development of LFPs. This provides a detailed overview of the production of LFPs utilizing conjugated polymers, as well as the imaging techniques employed for their visualization. Particular attention is given to conjugated polymer nanoparticles and polymer dots. In addition, the most often employed techniques for producing conjugated polymer-based nanoparticles have also been examined. Additionally, it encompasses the historical background of LFP identification and offers a valuable understanding of the diverse conventional approaches investigated for their advancement. This article offers a comprehensive examination of conjugated polymers as contrasting agents for imaging LFPs on different surfaces.