Latent blood fingerprints (LBFPs) are critical forensic evidence in violent crime investigations, offering unique personal identification markers. However, current visualization techniques often suffer from low sensitivity, complex procedures, or poor compatibility with challenging substrates. This study presents a novel, simple, and highly effective method for LBFP development using an amphiphilic fluorescent conjugated polymer, PPEOR-NH₃⁺, integrated with a cotton-pad-based protocol. The polymer features two protonated primary amino groups and two long dodecyloxy ester chains per repeat unit, enabling strong affinity to blood proteins while maintaining solubility in organic solvents. By simply covering the fingerprint substrate with a polymer-soaked cotton pad and peeling it off after 1–2 minutes, clear and detailed fingerprint patterns—showing ridge structures, sweat pores, and fine texture—are revealed under 415 nm excitation light. This method successfully visualizes LBFPs on diverse surfaces including painted wood, multicolored cans, dark plastic, aluminum foil, and glass, even when the prints are aged over 600 days or contaminated with sebaceous matter, dust, or mold. Gray value analysis confirms a significant enhancement in ridge-furrow contrast, with differences increasing from less than 20 before development to up to 120 post-development.p53 Antibody manufacturer Importantly, the developed images exhibit exceptional stability during long-term storage and resist solvent washing, indicating robustness in real-world conditions.TWIST1 Antibody web Crucially, no degradation of DNA is observed after treatment, preserving the potential for downstream genetic profiling. Mechanistic studies reveal that image formation depends on the balance between polymer-substrate affinity and polymer-blood interaction: positive images form on low-affinity substrates like aluminum foil due to stronger emission on ridges, while inverted images appear on high-affinity substrates where furrows fluoresce more intensely.PMID:35064001 The key to stability lies in covalent bonding between the protonated amino groups of the polymer and carboxyl groups in blood proteins, confirmed through dissociation agent tests and microsphere experiments. This work demonstrates a rational molecular design strategy for conjugated polymers in forensic applications, combining simplicity, universality, and nondestructiveness. The approach holds great promise for routine use in criminal investigations, particularly in cases involving bloodied scenes with complex backgrounds or degraded evidence.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
